Pub Date : 2025-12-29DOI: 10.1016/j.beproc.2025.105324
Rui Han , Jun Zhang , Xin-Hui Chen , Jing-Wen Duo , Yi-Yi Li , Yi-Ran Chen , Si-Tong Chen , Lin-Xiang Liu , Xiang-Haoran Lin
Mating behaviour plays a key role in animal reproduction and profoundly affects the physiological state and behavioural performance of individuals. Although numerous studies have focused on the behavioural responses of single-sex groups of Drosophila melanogaster under mating contexts, systematic comparisons of male and female fruit flies across different mating contexts are still relatively limited. This study investigated the locomotion of 86 male and female fruit flies under different mating contexts, including virgin, continuously exposed to the opposite sex (mated), beginning cohabitation with the opposite sex on the 8th day of the experiment (virgin-mated), and opposite-sex cohabitation on the 8th day and switching to same-sex cohabitation (mated-deprived). The results showed that virgin males exhibited the highest overall movement speed and that continuous exposure to the opposite sex led to a transient reduction in male movement speed. In contrast, females displayed a temporary increase in movement speed under opposite-sex cohabitation but rapidly returned to levels comparable to virgins. These sex-specific and time-dependent changes indicate that mating context exerts dynamic effects on movement speed. Moreover, in contrast to the negative effects of social isolation reported in previous studies, our findings suggest that mating status and social environment jointly shape locomotor performance under non-isolated conditions. Overall, this study highlights how males and females dynamically adjust locomotor strategies in response to changing reproductive and social contexts, providing an evolutionary perspective on behavioural plasticity and sex-specific trade-offs in insects.
{"title":"Sex differences in locomotor recovery across mating contexts in Drosophila melanogaster","authors":"Rui Han , Jun Zhang , Xin-Hui Chen , Jing-Wen Duo , Yi-Yi Li , Yi-Ran Chen , Si-Tong Chen , Lin-Xiang Liu , Xiang-Haoran Lin","doi":"10.1016/j.beproc.2025.105324","DOIUrl":"10.1016/j.beproc.2025.105324","url":null,"abstract":"<div><div>Mating behaviour plays a key role in animal reproduction and profoundly affects the physiological state and behavioural performance of individuals. Although numerous studies have focused on the behavioural responses of single-sex groups of <em>Drosophila melanogaster</em> under mating contexts, systematic comparisons of male and female fruit flies across different mating contexts are still relatively limited. This study investigated the locomotion of 86 male and female fruit flies under different mating contexts, including virgin, continuously exposed to the opposite sex (mated), beginning cohabitation with the opposite sex on the 8th day of the experiment (virgin-mated), and opposite-sex cohabitation on the 8th day and switching to same-sex cohabitation (mated-deprived). The results showed that virgin males exhibited the highest overall movement speed and that continuous exposure to the opposite sex led to a transient reduction in male movement speed. In contrast, females displayed a temporary increase in movement speed under opposite-sex cohabitation but rapidly returned to levels comparable to virgins. These sex-specific and time-dependent changes indicate that mating context exerts dynamic effects on movement speed. Moreover, in contrast to the negative effects of social isolation reported in previous studies, our findings suggest that mating status and social environment jointly shape locomotor performance under non-isolated conditions. Overall, this study highlights how males and females dynamically adjust locomotor strategies in response to changing reproductive and social contexts, providing an evolutionary perspective on behavioural plasticity and sex-specific trade-offs in insects.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105324"},"PeriodicalIF":1.5,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145877629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-23DOI: 10.1016/j.beproc.2025.105323
Chris T. Tromborg, Richard G. Coss, Kenneth R. Henry
California ground squirrels (Otospermophilus becheeyi) exhibit adaptive variation to their local environments based on antipredator, immunological, and social-communication evaluations. The following pair of experiments investigated the acoustic and behavioral responses of California ground squirrels from the higher-elevation Sierra Valley (alt. ∼1900 m) and from the lower-elevation Sunol region (alt. ∼270 m). Analyses of their genetic distance suggest that these populations diverged during the Late Pleistocene. The first experiment compared small groups from these populations on the basis of their auditory brainstem responses (ABR) to a range of sound frequencies. The ABR audiograms of Sierra Valley squirrels showed greater acoustic sensitivity to frequencies lower than 4 kHz than the Sunol squirrels. Both groups exhibited similar audiograms for higher frequencies. Such an adaptation would be useful for coping with dangerous circumstances possibly masked by inclement weather. The second experiment compared the squirrel groups for several 9-hr observation periods focusing on the number of egress bouts from nest boxes centered in a laboratory room equipped with sound playback equipment to simulate far-field naturalistic sounds. Three sound treatments were compared: 1) ambient room sound, 2) temperate forest, and 3) rainstorm. Analyses indicated that the higher-altitude Sierra Valley squirrels were reliably less likely to leave the nestbox to explore the room than were low-altitude Sunol squirrels under the rain treatment. The results of both studies suggest that the enhanced low-frequency hearing of Sierra Valley squirrels is a sensory adaptation for coping with the reduced sound transmission of low frequencies at higher altitudes.
{"title":"Adaptive variation in the acoustic sensitivity of California ground squirrels (Otospermophilus beecheyi) living in higher- and lower-elevation habitats","authors":"Chris T. Tromborg, Richard G. Coss, Kenneth R. Henry","doi":"10.1016/j.beproc.2025.105323","DOIUrl":"10.1016/j.beproc.2025.105323","url":null,"abstract":"<div><div>California ground squirrels (<em>Otospermophilus becheeyi</em>) exhibit adaptive variation to their local environments based on antipredator, immunological, and social-communication evaluations. The following pair of experiments investigated the acoustic and behavioral responses of California ground squirrels from the higher-elevation Sierra Valley (alt. ∼1900 m) and from the lower-elevation Sunol region (alt. ∼270 m). Analyses of their genetic distance suggest that these populations diverged during the Late Pleistocene. The first experiment compared small groups from these populations on the basis of their auditory brainstem responses (ABR) to a range of sound frequencies. The ABR audiograms of Sierra Valley squirrels showed greater acoustic sensitivity to frequencies lower than 4 kHz than the Sunol squirrels. Both groups exhibited similar audiograms for higher frequencies. Such an adaptation would be useful for coping with dangerous circumstances possibly masked by inclement weather. The second experiment compared the squirrel groups for several 9-hr observation periods focusing on the number of egress bouts from nest boxes centered in a laboratory room equipped with sound playback equipment to simulate far-field naturalistic sounds. Three sound treatments were compared: 1) ambient room sound, 2) temperate forest, and 3) rainstorm. Analyses indicated that the higher-altitude Sierra Valley squirrels were reliably less likely to leave the nestbox to explore the room than were low-altitude Sunol squirrels under the rain treatment. The results of both studies suggest that the enhanced low-frequency hearing of Sierra Valley squirrels is a sensory adaptation for coping with the reduced sound transmission of low frequencies at higher altitudes.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105323"},"PeriodicalIF":1.5,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145833061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Captive animals are commonly used in laboratory research, however, captive and wild animals often differ, limiting the applicability of laboratory findings based on captive animals to the “real” world. A comprehensive understanding of how captive and wild animals differ is necessary to assess if captive animals are suitable substitutes for their wild counterparts, however, few studies have compared cognition between captive and wild animals. In this study, we compared aspects of cognition between captive and wild fathead minnow (Pimephales promelas) to investigate how life in captivity might impact traits essential to fitness in the wild. Specifically, we assessed aversive learning performance using an associative learning assay and a more complex reversal learning assay, and we also measured anxiety and brain mass. Performance in the associative learning task was negatively correlated with performance in the reversal learning task, suggesting a potential tradeoff. No differences were observed between captive and wild fish in associative learning performance, anxiety, or brain mass, but wild fish were three times more likely to complete the more complex reversal learning task. Aversive reversal learning, which appears to be dampened in captive fathead minnow, may be particularly relevant for appropriate antipredator responses and fitness in challenging or fluctuating environments. We advocate for further research comparing wild and captive animal cognition and urge researchers to exercise caution when generalizing results from captive animals to wild populations.
{"title":"Cognition in captivity: Investigating learning, anxiety, and brain mass differences between captive and wild fathead minnow","authors":"Megan Dorothy Cyr , Jacqueline Bikker , Adrienne Yau , Sigal Balshine","doi":"10.1016/j.beproc.2025.105322","DOIUrl":"10.1016/j.beproc.2025.105322","url":null,"abstract":"<div><div>Captive animals are commonly used in laboratory research, however, captive and wild animals often differ, limiting the applicability of laboratory findings based on captive animals to the “real” world. A comprehensive understanding of how captive and wild animals differ is necessary to assess if captive animals are suitable substitutes for their wild counterparts, however, few studies have compared cognition between captive and wild animals. In this study, we compared aspects of cognition between captive and wild fathead minnow (<em>Pimephales promelas)</em> to investigate how life in captivity might impact traits essential to fitness in the wild. Specifically, we assessed aversive learning performance using an associative learning assay and a more complex reversal learning assay, and we also measured anxiety and brain mass. Performance in the associative learning task was negatively correlated with performance in the reversal learning task, suggesting a potential tradeoff. No differences were observed between captive and wild fish in associative learning performance, anxiety, or brain mass, but wild fish were three times more likely to complete the more complex reversal learning task. Aversive reversal learning, which appears to be dampened in captive fathead minnow, may be particularly relevant for appropriate antipredator responses and fitness in challenging or fluctuating environments. We advocate for further research comparing wild and captive animal cognition and urge researchers to exercise caution when generalizing results from captive animals to wild populations.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105322"},"PeriodicalIF":1.5,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145761982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.beproc.2025.105321
Fionnghuala L.J. James , Sayed K. Ahamed , Cheng Yang , Jigme Thinley , Carmelo M. Vicario , Juan J. Canales , Sukhwinder S. Sohal , Richard Wilson , Luke R. Johnson , Vanni Caruso
The processes of memory consolidation and reconsolidation are important in understanding the dynamics of memory storage and modification. Models to condition aversive memory have been characterised in rodents yet have been less explored in invertebrates such as planaria. Planaria are a potentially important animal model for the study of threat learning and memory as they can learn conditioned responses and may show conserved neural mechanisms underpinning these responses compared to mammals. However, no model for the study of memory in classical threat conditioning exists for planaria. The aim of this study is to replicate a standardised cued threat conditioning model for memory acquisition and reconsolidation in mice, in brown planaria (Girardia dorotocephala), using shock as the unconditioned stimulus (US) and light as the conditioned stimulus (CS). Defensive behaviours (C-shaped movements and scrunching) were assessed to evaluate learning. Planaria underwent memory acquisition training for a total of 18 learning trials. In the consolidation model, memory retention was tested 24 h after the final training session with a CS exposure. In the reconsolidation model, memory stability was assessed using a recall test 24 h after a reactivation session. In both tests, the paired shock-light group exhibited a significant increase in defensive behaviours, compared to all control groups, suggesting that the pairing of both shock and light was essential for forming a lasting memory. Furthermore, planaria exhibited a gradual extinction of defensive responses to the CS. These findings highlight the utility of planaria for studying associative learning and memory, including memory reconsolidation.
{"title":"Adapting rodent cued threat conditioning to planarians: Memory acquisition, consolidation, and reconsolidation","authors":"Fionnghuala L.J. James , Sayed K. Ahamed , Cheng Yang , Jigme Thinley , Carmelo M. Vicario , Juan J. Canales , Sukhwinder S. Sohal , Richard Wilson , Luke R. Johnson , Vanni Caruso","doi":"10.1016/j.beproc.2025.105321","DOIUrl":"10.1016/j.beproc.2025.105321","url":null,"abstract":"<div><div>The processes of memory consolidation and reconsolidation are important in understanding the dynamics of memory storage and modification. Models to condition aversive memory have been characterised in rodents yet have been less explored in invertebrates such as planaria. Planaria are a potentially important animal model for the study of threat learning and memory as they can learn conditioned responses and may show conserved neural mechanisms underpinning these responses compared to mammals. However, no model for the study of memory in classical threat conditioning exists for planaria. The aim of this study is to replicate a standardised cued threat conditioning model for memory acquisition and reconsolidation in mice, in brown planaria (<em>Girardia dorotocephala</em>), using shock as the unconditioned stimulus (US) and light as the conditioned stimulus (CS). Defensive behaviours (C-shaped movements and scrunching) were assessed to evaluate learning. Planaria underwent memory acquisition training for a total of 18 learning trials. In the consolidation model, memory retention was tested 24 h after the final training session with a CS exposure. In the reconsolidation model, memory stability was assessed using a recall test 24 h after a reactivation session. In both tests, the paired shock-light group exhibited a significant increase in defensive behaviours, compared to all control groups, suggesting that the pairing of both shock and light was essential for forming a lasting memory. Furthermore, planaria exhibited a gradual extinction of defensive responses to the CS. These findings highlight the utility of planaria for studying associative learning and memory, including memory reconsolidation.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"235 ","pages":"Article 105321"},"PeriodicalIF":1.5,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145751461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1016/j.beproc.2025.105320
Marilia Pinheiro de Carvalho , Ana Paula Rocha , Soraya Tavares , Armando Machado , Marco Vasconcelos
Given a choice between a simple option offering a preferred-food item (e.g., a grape, G) and a combo option offering the same preferred-food item plus a less-preferred food item (e.g., a grape + a slice of cucumber, GC), animals often behave suboptimally by either being indifferent between the two options or by preferring the simple option—the “less-is-better” effect. To explain indifference, the selective-value hypothesis assumes that, in the choice context, the subjective value (V) of the less-preferred food is zero (i.e., VGC = VG + 0 = VG). To explain the less-is-better effect, the average-quality hypothesis assumes that the value of the combo equals the average of its components’ values [i.e., VGC = Average(VG,VC) < VG]. No unified account explains both sets of experimental findings. To test these hypotheses further, we presented six capuchin monkeys (Sapajus sp.) with a variety of choice tests, some simple (GC vs. G) and some complex (2G1C vs. 3G1C; or 2C1G vs. 3C1G), with a final sample of four individuals per test. The results confirm that capuchin monkeys also behave suboptimally, revealing either indifference or the less-is-better effect. Crucially, our findings suggest that the value of the less-preferred food, C, may become negative through a contrast-like effect. By expanding the selective-value hypothesis to accommodate situations where the less-preferred item’s value may be reduced to zero or become negative, we suggest a unified, process-based account of the two sets of research findings.
如果让动物在提供偏好食物的简单选项（如葡萄，G）和提供相同偏好食物加上不太偏好食物的组合选项（如葡萄+一片黄瓜，GC）之间做出选择，它们的行为通常不是最优的，要么对这两种选项漠不关心，要么更喜欢简单的选项——即“越少越好”的效果。为了解释无差异，选择价值假设假设，在选择情境中，不太受欢迎的食物的主观价值(V)为零（即VGC = VG + 0 = VG）。为了解释“越少越好”的效应，平均质量假设假设组合的值等于其组成部分值的平均值[即VGC = average (VG，VC) < VG]。没有统一的解释可以解释这两组实验结果。为了进一步验证这些假设，我们对6只卷尾猴（Sapajus sp.）进行了各种选择测试，有些是简单的（GC vs. G），有些是复杂的（2G1C vs. 3G1C；或2C1G vs. 3C1G），每次测试的最终样本为4个人。结果证实，卷尾猴的行为也不是最优的，要么表现出冷漠，要么表现出越少越好的效果。至关重要的是，我们的研究结果表明，不太受欢迎的食物C的价值可能会通过一种类似对比的效应变成负值。通过扩展选择价值假设，以适应不太受欢迎的项目的价值可能减少到零或变为负值的情况，我们建议对两组研究结果进行统一的，基于过程的说明。
{"title":"The ‘less-is-better’ effect in capuchin monkeys (Sapajus sp.): Some data and a contrast-like hypothesis","authors":"Marilia Pinheiro de Carvalho , Ana Paula Rocha , Soraya Tavares , Armando Machado , Marco Vasconcelos","doi":"10.1016/j.beproc.2025.105320","DOIUrl":"10.1016/j.beproc.2025.105320","url":null,"abstract":"<div><div>Given a choice between a simple option offering a preferred-food item (e.g., a grape, G) and a combo option offering the same preferred-food item <em>plus</em> a less-preferred food item (e.g., a grape + a slice of cucumber, GC), animals often behave suboptimally by either being indifferent between the two options or by preferring the simple option—the “less-is-better” effect. To explain indifference, the selective-value hypothesis assumes that, in the choice context, the subjective value (V) of the less-preferred food is zero (i.e., V<sub>GC</sub> = V<sub>G</sub> + 0 = V<sub>G</sub>). To explain the less-is-better effect, the average-quality hypothesis assumes that the value of the combo equals the average of its components’ values [i.e., V<sub>GC</sub> = Average(V<sub>G</sub>,V<sub>C</sub>) < V<sub>G</sub>]. No unified account explains both sets of experimental findings. To test these hypotheses further, we presented six capuchin monkeys (<em>Sapajus</em> sp.) with a variety of choice tests, some simple (GC vs. G) and some complex (2G1C vs. 3G1C; or 2C1G vs. 3C1G), with a final sample of four individuals per test. The results confirm that capuchin monkeys also behave suboptimally, revealing either indifference or the less-is-better effect. Crucially, our findings suggest that the value of the less-preferred food, C, may become negative through a contrast-like effect. By expanding the selective-value hypothesis to accommodate situations where the less-preferred item’s value may be reduced to zero or become negative, we suggest a unified, process-based account of the two sets of research findings.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"234 ","pages":"Article 105320"},"PeriodicalIF":1.5,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145699622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.beproc.2025.105312
Sergei A. Fedotov , Anna A. Goncharova , Natalia G. Besedina , Larisa V. Danilenkova , Elena A. Kamysheva , Ulyana N. Solodukhina , Aleksandr A. Rubel , Julia V. Bragina
The courtship ritual of Drosophila males toward females has been extensively studied to elucidate the mechanisms of behavioral plasticity in insects. Courtship is an innate, fixed sequence of behaviors that results in mating. The implementation of this instinct involves adjusting specific parameters of the courtship behaviors, such as sound production, to increase the likelihood of successful copulation. Moreover, courtship can be temporarily suppressed following an unsuccessful attempt with a previously mated female. While the neural mechanisms underlying courtship learning are well described, the interaction between male behavioral sequencing and known female-derived determinants of suppression (e.g., cVA from mated females and active rejection behaviors) remains unclear. In our study, we characterized the structure of male courtship towards virgin, mated, and immature females. We found that changes in the frequencies of transitions between courtship behaviors provide adaptive restructuring in the implementation of this ritual. Courtship towards mated females causes males to reinitiate the ritual more frequently, and we hypothesize that repeated unsuccessful initiations may ultimately result in courtship suppression. When courting immature females, males neither attempt copulation nor restart the ritual, which may explain the absence of courtship suppression with this type of female and raises the question of the evolutionary significance of courtship towards immature females.
{"title":"The structure of courtship behavior in Drosophila males: Boundaries of plasticity","authors":"Sergei A. Fedotov , Anna A. Goncharova , Natalia G. Besedina , Larisa V. Danilenkova , Elena A. Kamysheva , Ulyana N. Solodukhina , Aleksandr A. Rubel , Julia V. Bragina","doi":"10.1016/j.beproc.2025.105312","DOIUrl":"10.1016/j.beproc.2025.105312","url":null,"abstract":"<div><div>The courtship ritual of Drosophila males toward females has been extensively studied to elucidate the mechanisms of behavioral plasticity in insects. Courtship is an innate, fixed sequence of behaviors that results in mating. The implementation of this instinct involves adjusting specific parameters of the courtship behaviors, such as sound production, to increase the likelihood of successful copulation. Moreover, courtship can be temporarily suppressed following an unsuccessful attempt with a previously mated female. While the neural mechanisms underlying courtship learning are well described, the interaction between male behavioral sequencing and known female-derived determinants of suppression (e.g., cVA from mated females and active rejection behaviors) remains unclear. In our study, we characterized the structure of male courtship towards virgin, mated, and immature females. We found that changes in the frequencies of transitions between courtship behaviors provide adaptive restructuring in the implementation of this ritual. Courtship towards mated females causes males to reinitiate the ritual more frequently, and we hypothesize that repeated unsuccessful initiations may ultimately result in courtship suppression. When courting immature females, males neither attempt copulation nor restart the ritual, which may explain the absence of courtship suppression with this type of female and raises the question of the evolutionary significance of courtship towards immature females.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"234 ","pages":"Article 105312"},"PeriodicalIF":1.5,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145653330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-28DOI: 10.1016/j.beproc.2025.105311
Xinxiang Su , Junjun Pu , Jinxia Liao , Yuqian Tang , Liting Feng , Zhen Wu
Objective
This study aimed to explore the effect of Alzheimer's disease (AD) rats on the drinking behavior of Sprague-Dawley (SD) rats and observe the ultrasonic vocalizations (USVs) of AD rats and SD rats.
Methods
The 12 AD rats were equally divided into two groups (6 rats per group), and the 36 SD rats were divided into 6 groups (6 rats per group), with no rat reused across different experimental groups. Two independent experimental tasks were conducted: 1) A test field with a sugar area (containing 10 % sucrose solution) and a chili area (containing 0.02 % capsaicin solution) was constructed. The drinking behavior of SD rats (placed in the middle area of the test field) was recorded in the presence of different "guiding rats" (placed in the side area of the test field). The experiment was divided into 5 groups: unguided group (UG, no guiding rats in the side area), normal SD rats guiding group (NG), AD rats guiding group (ADG), AD rats guiding group with memantine administration (ADMG), and the Ultrasonic Vocalizations Guiding Group (USVsG, an animal ultrasonic sound player was used to broadcast the USVs). Additionally, the escape latency results of the Morris water maze test, a commonly used cognitive evaluation task in AD rats, were compared and correlated with the drinking behavior results — the core hypothesis here was to verify whether the drinking behavior method established in this study could serve as a valid tool for assessing AD behavioral phenotypes, consistent with the evaluation effect of the traditional Morris water maze. 2) USV characteristics of SD rats, AD rats, and memantine-administered AD rats were recorded and analyzed separately.
Results
Compared with the UG, the NG had more drinking bouts in the sugar area and fewer in the chili area. In contrast, the ADG showed the opposite trend vs. NG, indicating impaired social information transmission in AD rats. For USVs, normal SD rats had environment-specific frequency differentiation: dominant high-frequency USVs in sugar-water and low-frequency ones in chili-water, while AD rats had disorganized USV frequency bands. After memantine intervention, ADMG had enhanced sugar preference, shortened Morris water maze escape latency, and USV frequencies gradually approaching normal SD rats. Moreover, USVsG had no obvious difference in drinking behavior vs. NG, confirming USVs as the core medium of social guidance.
Conclusion
This study reveals AD rats' abnormal USV characteristics, preliminarily lays an experimental basis for an evaluation method combining USVs and drinking behavior, provides a new non-invasive, low-cost perspective for assessing AD rats' behavioral phenotypes, and verifies this method correlates with traditional cognitive evaluation (Morris water maze) and can effectively reflect the improvement of AD behavioral phenotypes after memantine intervention.
{"title":"Assessment of ultrasonic vocalization-mediated communication deficits in AD rats: A social learning paradigm using conspecific drinking behavior","authors":"Xinxiang Su , Junjun Pu , Jinxia Liao , Yuqian Tang , Liting Feng , Zhen Wu","doi":"10.1016/j.beproc.2025.105311","DOIUrl":"10.1016/j.beproc.2025.105311","url":null,"abstract":"<div><h3>Objective</h3><div>This study aimed to explore the effect of Alzheimer's disease (AD) rats on the drinking behavior of Sprague-Dawley (SD) rats and observe the ultrasonic vocalizations (USVs) of AD rats and SD rats.</div></div><div><h3>Methods</h3><div>The 12 AD rats were equally divided into two groups (6 rats per group), and the 36 SD rats were divided into 6 groups (6 rats per group), with no rat reused across different experimental groups. Two independent experimental tasks were conducted: 1) A test field with a sugar area (containing 10 % sucrose solution) and a chili area (containing 0.02 % capsaicin solution) was constructed. The drinking behavior of SD rats (placed in the middle area of the test field) was recorded in the presence of different \"guiding rats\" (placed in the side area of the test field). The experiment was divided into 5 groups: unguided group (UG, no guiding rats in the side area), normal SD rats guiding group (NG), AD rats guiding group (ADG), AD rats guiding group with memantine administration (ADMG), and the Ultrasonic Vocalizations Guiding Group (USVsG, an animal ultrasonic sound player was used to broadcast the USVs). Additionally, the escape latency results of the Morris water maze test, a commonly used cognitive evaluation task in AD rats, were compared and correlated with the drinking behavior results — the core hypothesis here was to verify whether the drinking behavior method established in this study could serve as a valid tool for assessing AD behavioral phenotypes, consistent with the evaluation effect of the traditional Morris water maze. 2) USV characteristics of SD rats, AD rats, and memantine-administered AD rats were recorded and analyzed separately.</div></div><div><h3>Results</h3><div>Compared with the UG, the NG had more drinking bouts in the sugar area and fewer in the chili area. In contrast, the ADG showed the opposite trend vs. NG, indicating impaired social information transmission in AD rats. For USVs, normal SD rats had environment-specific frequency differentiation: dominant high-frequency USVs in sugar-water and low-frequency ones in chili-water, while AD rats had disorganized USV frequency bands. After memantine intervention, ADMG had enhanced sugar preference, shortened Morris water maze escape latency, and USV frequencies gradually approaching normal SD rats. Moreover, USVsG had no obvious difference in drinking behavior vs. NG, confirming USVs as the core medium of social guidance.</div></div><div><h3>Conclusion</h3><div>This study reveals AD rats' abnormal USV characteristics, preliminarily lays an experimental basis for an evaluation method combining USVs and drinking behavior, provides a new non-invasive, low-cost perspective for assessing AD rats' behavioral phenotypes, and verifies this method correlates with traditional cognitive evaluation (Morris water maze) and can effectively reflect the improvement of AD behavioral phenotypes after memantine intervention.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"234 ","pages":"Article 105311"},"PeriodicalIF":1.5,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145647203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-22DOI: 10.1016/j.beproc.2025.105309
C.M. Bradshaw
An adjusting-concentration schedule is described, in which rats made choices between a fructose solution of fixed concentration (cB) and a sucrose solution the concentration of which (cA) was adjusted in successive blocks of trials according to the rat’s preference in the preceding block. If the rat showed preference for fructose in block n, cA was increased by 20 % in block n + 1; if the rat preferred sucrose in block n, cA was reduced by 20 % in block n + 1. The concentration of sucrose in the final five of fifteen sessions was taken as the indifference concentration of sucrose (cA(50)). cB was varied across successive phases of the experiment, between 200 and 800 mM, and the resulting values of cA(50) were measured. An equation derived from the Multiplicative Hyperbolic Model of reinforcer value (MHM) was used to analyse the relation between cB and cA(50). The concentration ratio (cB/cA(50)) was significantly greater than unity at all values of cB, there being no significant deviation of the slope of the relation between cB/cA(50) and cB from zero. The results suggest that rats prefer sucrose to fructose across a broad range of concentrations, but the asymptotes of the conventration/value functions of sucrose and fructose are similar.
{"title":"Application of a novel adjusting-concentration schedule to compare the reinforcing effectiveness of sucrose and fructose","authors":"C.M. Bradshaw","doi":"10.1016/j.beproc.2025.105309","DOIUrl":"10.1016/j.beproc.2025.105309","url":null,"abstract":"<div><div>An adjusting-concentration schedule is described, in which rats made choices between a fructose solution of fixed concentration (<em>c</em><sub>B</sub>) and a sucrose solution the concentration of which (<em>c</em><sub>A</sub>) was adjusted in successive blocks of trials according to the rat’s preference in the preceding block. If the rat showed preference for fructose in block <em>n</em>, <em>c</em><sub>A</sub> was increased by 20 % in block <em>n</em> + 1; if the rat preferred sucrose in block <em>n</em>, <em>c</em><sub>A</sub> was reduced by 20 % in block <em>n</em> + 1. The concentration of sucrose in the final five of fifteen sessions was taken as the indifference concentration of sucrose (<em>c</em><sub>A(50)</sub>). <em>c</em><sub>B</sub> was varied across successive phases of the experiment, between 200 and 800 mM, and the resulting values of <em>c</em><sub>A(50)</sub> were measured. An equation derived from the Multiplicative Hyperbolic Model of reinforcer value (MHM) was used to analyse the relation between <em>c</em><sub>B</sub> and <em>c</em><sub>A(50)</sub>. The concentration ratio (<em>c</em><sub>B</sub>/<em>c</em><sub>A(50)</sub>) was significantly greater than unity at all values of <em>c</em><sub>B</sub>, there being no significant deviation of the slope of the relation between <em>c</em><sub>B</sub>/<em>c</em><sub>A(50)</sub> and <em>c</em><sub>B</sub> from zero. The results suggest that rats prefer sucrose to fructose across a broad range of concentrations, but the asymptotes of the conventration/value functions of sucrose and fructose are similar.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"234 ","pages":"Article 105309"},"PeriodicalIF":1.5,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145595536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-20DOI: 10.1016/j.beproc.2025.105308
Angela J. Barbosa, Katie E. McGhee
Dealing with novelty can be challenging for animals. Approaching unfamiliar objects and environments allows individuals to discover and exploit new food sources and habitats, but novelty can also be dangerous and expose individuals to unfamiliar predators or toxic foods. Observing how others react to novel objects can enable an individual to indirectly assess the risks or benefits associated with particular objects without putting themselves directly in harm’s way via social transmission of information. Using the western mosquitofish (Gambusia affinis), we first manipulated whether individuals either witnessed a group of conspecifics interacting with a novel object in a beaker (shoal treatment) or witnessed the novel object alone in an empty beaker (alone treatment). Following this exposure, individuals then encountered that same object on their own and we measured how quickly they approached the object. We found that the effect of witnessing a group encounter a novel object depended on the sex and size of the focal individual. Seeing a group around a novel object caused males and similarly small-sized females to approach the object more quickly when they encountered it on their own later, compared to seeing the novel object without surrounding conspecifics. In contrast, large females were willing to approach the object regardless of the social context under which they had first encountered it. Sex, body size, and/or personality differences might affect the benefits of the social context and determine whether conspecifics attract individuals to a novel object.
{"title":"Witnessing others interact with a novel object has sex- and size-specific effects on neophilia in mosquitofish","authors":"Angela J. Barbosa, Katie E. McGhee","doi":"10.1016/j.beproc.2025.105308","DOIUrl":"10.1016/j.beproc.2025.105308","url":null,"abstract":"<div><div>Dealing with novelty can be challenging for animals. Approaching unfamiliar objects and environments allows individuals to discover and exploit new food sources and habitats, but novelty can also be dangerous and expose individuals to unfamiliar predators or toxic foods. Observing how others react to novel objects can enable an individual to indirectly assess the risks or benefits associated with particular objects without putting themselves directly in harm’s way via social transmission of information. Using the western mosquitofish (<em>Gambusia affinis</em>), we first manipulated whether individuals either witnessed a group of conspecifics interacting with a novel object in a beaker (shoal treatment) or witnessed the novel object alone in an empty beaker (alone treatment). Following this exposure, individuals then encountered that same object on their own and we measured how quickly they approached the object. We found that the effect of witnessing a group encounter a novel object depended on the sex and size of the focal individual. Seeing a group around a novel object caused males and similarly small-sized females to approach the object more quickly when they encountered it on their own later, compared to seeing the novel object without surrounding conspecifics. In contrast, large females were willing to approach the object regardless of the social context under which they had first encountered it. Sex, body size, and/or personality differences might affect the benefits of the social context and determine whether conspecifics attract individuals to a novel object.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"234 ","pages":"Article 105308"},"PeriodicalIF":1.5,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145581671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-20DOI: 10.1016/j.beproc.2025.105310
Rebeca Emanuelle da Silva Castor , Rafaela Tadei , Paulo de Souza , Elaine Cristina Mathias da Silva , Rogério Hartung Toppa
The use of technology as a tool for evaluating insect behavior provides significant advantages to researchers, as it increases the amount of collected data, reduces observer bias, and minimizes the time and effort required for direct field observations. However, when incorporating technology into research methodologies, it is crucial to ensure that the tool does not alter the natural behavior of the studied individuals. In recent years, the use of radiofrequency electronic identification (RFID) to monitor bees has increased significantly. Yet, little is known about its potential effects on bee behavior, mainly in stingless bees. To assess the influence of electronic tags, we evaluated locomotion parameters and foraging choices by comparing feeders with and without the neonicotinoid insecticide imidacloprid in the stingless bee Melipona quadrifasciata under laboratory conditions using video tracking. Whereas the presence of electronic tags did not affect the food choice as measured by the frequency of bee visits to contaminated versus uncontaminated food sources, it did influence locomotion. Tagged bees exhibited reduced average speed, lower rotation frequency, shorter distances traveled, and altered arena exploration patterns. These behavioral modifications observed in laboratory conditions highlight important considerations for applying RFID technology in field studies monitoring bee behavior.
{"title":"Influence of RFID tags on Melipona quadrifasciata behavior: Effects on locomotion and food choice","authors":"Rebeca Emanuelle da Silva Castor , Rafaela Tadei , Paulo de Souza , Elaine Cristina Mathias da Silva , Rogério Hartung Toppa","doi":"10.1016/j.beproc.2025.105310","DOIUrl":"10.1016/j.beproc.2025.105310","url":null,"abstract":"<div><div>The use of technology as a tool for evaluating insect behavior provides significant advantages to researchers, as it increases the amount of collected data, reduces observer bias, and minimizes the time and effort required for direct field observations. However, when incorporating technology into research methodologies, it is crucial to ensure that the tool does not alter the natural behavior of the studied individuals. In recent years, the use of radiofrequency electronic identification (RFID) to monitor bees has increased significantly. Yet, little is known about its potential effects on bee behavior, mainly in stingless bees. To assess the influence of electronic tags, we evaluated locomotion parameters and foraging choices by comparing feeders with and without the neonicotinoid insecticide imidacloprid in the stingless bee <em>Melipona quadrifasciata</em> under laboratory conditions using video tracking. Whereas the presence of electronic tags did not affect the food choice as measured by the frequency of bee visits to contaminated versus uncontaminated food sources, it did influence locomotion. Tagged bees exhibited reduced average speed, lower rotation frequency, shorter distances traveled, and altered arena exploration patterns. These behavioral modifications observed in laboratory conditions highlight important considerations for applying RFID technology in field studies monitoring bee behavior.</div></div>","PeriodicalId":8746,"journal":{"name":"Behavioural Processes","volume":"234 ","pages":"Article 105310"},"PeriodicalIF":1.5,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145581678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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