Taste receptor cells are morphologically classified as types II and III. Type II cells form a unique type of synapses referred to as channel synapses where calcium homeostasis modulator 1 (CALHM1) together with CALHM3 forms voltage-gated channels that release the neurotransmitter, adenosine triphosphate (ATP). To validate the proposed structural model of channel synapses, the ultrastructural localization of CALHM1 in type II cells of both fungiform and circumvallate taste buds was examined. A monoclonal antibody against CALHM1 was developed and its localization was evaluated via immunofluorescence and immunoelectron microscopy using the immunogold-silver labeling technique. CALHM1 was detected as puncta using immunofluorescence and along the presynaptic membrane of channel synapses facing atypical mitochondria, which provide ATP, by immunoelectron microscopy. In addition, it was detected along the plasma membrane lined by subsurface cisternae at sites apposed to afferent nerve fibers. Our results support the validity of a previously proposed structural model for channel synapses and provide insights into the function of subsurface cisternae whose function in taste receptor cells is unknown. We also examined the localization of CALHM1 in hybrid synapses of type III cells, which are conventional chemical synapses accompanied by mitochondria similar to atypical mitochondria of channel synapses. CALHM1 was not detected in the six hybrid synapses examined using immunoelectron microscopy. We further performed double immunolabeling for CALHM1 and Bassoon, which is detected as puncta corresponding to conventional vesicular synapses in type III cells. Our observations suggest that at least some, and probably most, hybrid synapses are not accompanied by CALHM1.
味觉感受器细胞在形态上分为 II 型和 III 型。Ⅱ型细胞形成一种独特的突触,被称为通道突触,其中钙稳态调节器1(CALHM1)与CALHM3一起形成电压门控通道,释放神经递质三磷酸腺苷(ATP)。为了验证所提出的通道突触结构模型,研究人员检测了 CALHM1 在菌形味蕾和环状味蕾 II 型细胞中的超微结构定位。研究人员开发了针对 CALHM1 的单克隆抗体,并利用免疫金银标记技术通过免疫荧光和免疫电镜对其定位进行了评估。通过免疫荧光,CALHM1 以点状形式被检测到;通过免疫电镜,CALHM1 沿通道突触前膜被检测到,通道突触前膜面向提供 ATP 的非典型线粒体。此外,在与传入神经纤维相邻的部位,沿着表面下贮水池内衬的质膜也检测到了这种物质。我们的研究结果支持了之前提出的通道突触结构模型的正确性,并对表面下贮液器的功能提供了见解,而这些贮液器在味觉感受器细胞中的功能尚不清楚。我们还研究了 CALHM1 在 III 型细胞混合突触中的定位情况,这种突触是传统的化学突触,伴有与通道突触的非典型线粒体相似的线粒体。使用免疫电镜检查的六个混合突触中均未检测到 CALHM1。我们进一步对 CALHM1 和巴松进行了双重免疫标记,在 III 型细胞中,巴松被检测为与传统囊泡突触相对应的点。我们的观察结果表明,至少有一部分(可能是大部分)混合突触不伴有 CALHM1。
{"title":"Ultrastructural localization of calcium homeostasis modulator 1 in mouse taste buds.","authors":"Rio Ikuta, Yuu Kakinohana, Shun Hamada","doi":"10.1093/chemse/bjae019","DOIUrl":"10.1093/chemse/bjae019","url":null,"abstract":"<p><p>Taste receptor cells are morphologically classified as types II and III. Type II cells form a unique type of synapses referred to as channel synapses where calcium homeostasis modulator 1 (CALHM1) together with CALHM3 forms voltage-gated channels that release the neurotransmitter, adenosine triphosphate (ATP). To validate the proposed structural model of channel synapses, the ultrastructural localization of CALHM1 in type II cells of both fungiform and circumvallate taste buds was examined. A monoclonal antibody against CALHM1 was developed and its localization was evaluated via immunofluorescence and immunoelectron microscopy using the immunogold-silver labeling technique. CALHM1 was detected as puncta using immunofluorescence and along the presynaptic membrane of channel synapses facing atypical mitochondria, which provide ATP, by immunoelectron microscopy. In addition, it was detected along the plasma membrane lined by subsurface cisternae at sites apposed to afferent nerve fibers. Our results support the validity of a previously proposed structural model for channel synapses and provide insights into the function of subsurface cisternae whose function in taste receptor cells is unknown. We also examined the localization of CALHM1 in hybrid synapses of type III cells, which are conventional chemical synapses accompanied by mitochondria similar to atypical mitochondria of channel synapses. CALHM1 was not detected in the six hybrid synapses examined using immunoelectron microscopy. We further performed double immunolabeling for CALHM1 and Bassoon, which is detected as puncta corresponding to conventional vesicular synapses in type III cells. Our observations suggest that at least some, and probably most, hybrid synapses are not accompanied by CALHM1.</p>","PeriodicalId":9771,"journal":{"name":"Chemical Senses","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140956373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Janine Gellrich, Pauline Breidel, Cahit Birdir, Elisabeth C Lohrer, Valentin A Schriever
In this study, the transfer of odorants, namely vanilla, and garlic, into the amniotic fluid (AF) during the second trimester was investigated by examination of collected AF samples through healthy adults. Eleven AF samples were collected from pregnant women (aged 32.9 ± 4.9 yr, 16-25 wk of gestation) undergoing diagnostic amniocentesis after eating garlic oil or vanilla powder in high-fat yogurt. The control group did not receive food before amniocentesis. Two vanilla, 3 garlic, and 6 control samples were collected through amniocentesis 60-120 min after ingestion. Samples were collected at -80 °C and carefully defrosted over 12 h at the same time point. Sixteen healthy volunteers (8 males, aged 26.5 ± 5.0 yr) were asked to judge AF samples with potential garlic or vanilla odors from controls in a 2-alternative forced choice (2AFC) paradigm. Judges were able to identify vanilla in the AF samples with an estimated probability of 50%, resulting in a significant P-value of < 0.001. In contrast, the identification of garlic was unsuccessful with a P-value of 0.86, and only 2 judges were able to identify both vanilla and garlic. According to the results of this study, the vanilla odor probably passes into the amniotic fluid.
{"title":"Smelling of the mothers' diet in amniotic fluid by adult noses.","authors":"Janine Gellrich, Pauline Breidel, Cahit Birdir, Elisabeth C Lohrer, Valentin A Schriever","doi":"10.1093/chemse/bjae003","DOIUrl":"10.1093/chemse/bjae003","url":null,"abstract":"<p><p>In this study, the transfer of odorants, namely vanilla, and garlic, into the amniotic fluid (AF) during the second trimester was investigated by examination of collected AF samples through healthy adults. Eleven AF samples were collected from pregnant women (aged 32.9 ± 4.9 yr, 16-25 wk of gestation) undergoing diagnostic amniocentesis after eating garlic oil or vanilla powder in high-fat yogurt. The control group did not receive food before amniocentesis. Two vanilla, 3 garlic, and 6 control samples were collected through amniocentesis 60-120 min after ingestion. Samples were collected at -80 °C and carefully defrosted over 12 h at the same time point. Sixteen healthy volunteers (8 males, aged 26.5 ± 5.0 yr) were asked to judge AF samples with potential garlic or vanilla odors from controls in a 2-alternative forced choice (2AFC) paradigm. Judges were able to identify vanilla in the AF samples with an estimated probability of 50%, resulting in a significant P-value of < 0.001. In contrast, the identification of garlic was unsuccessful with a P-value of 0.86, and only 2 judges were able to identify both vanilla and garlic. According to the results of this study, the vanilla odor probably passes into the amniotic fluid.</p>","PeriodicalId":9771,"journal":{"name":"Chemical Senses","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139650307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jörn Lötsch, Anne Wolter, Antje Hähner, Thomas Hummel
Clinical assessment of an individual's sense of smell has gained prominence, but its resource-intensive nature necessitates the exploration of self-administered methods. In this study, a cohort of 68 patients with olfactory loss and 55 controls were assessed using a recently introduced olfactory test. This test involves sorting 2 odorants (eugenol and phenylethyl alcohol) in 5 dilutions according to odor intensity, with an average application time of 3.5 min. The sorting task score, calculated as the mean of Kendall's Tau between the assigned and true dilution orders and normalized to [0,1], identified a cutoff for anosmia at a score ≤ 0.7. This cutoff, which marks the 90th percentile of scores obtained with randomly ordered dilutions, had a balanced accuracy of 89% (78% to 97%) for detecting anosmia, comparable to traditional odor threshold assessments. Retest evaluations suggested a score difference of ±0.15 as a cutoff for clinically significant changes in olfactory function. In conclusion, the olfactory sorting test represents a simple, self-administered approach to the detection of anosmia or preserved olfactory function. With balanced accuracy similar to existing brief olfactory tests, this method offers a practical and user-friendly alternative for screening anosmia, addressing the need for resource-efficient assessments in clinical settings.
{"title":"Odor dilution sorting as a clinical test of olfactory function: normative values and reliability data.","authors":"Jörn Lötsch, Anne Wolter, Antje Hähner, Thomas Hummel","doi":"10.1093/chemse/bjae008","DOIUrl":"10.1093/chemse/bjae008","url":null,"abstract":"<p><p>Clinical assessment of an individual's sense of smell has gained prominence, but its resource-intensive nature necessitates the exploration of self-administered methods. In this study, a cohort of 68 patients with olfactory loss and 55 controls were assessed using a recently introduced olfactory test. This test involves sorting 2 odorants (eugenol and phenylethyl alcohol) in 5 dilutions according to odor intensity, with an average application time of 3.5 min. The sorting task score, calculated as the mean of Kendall's Tau between the assigned and true dilution orders and normalized to [0,1], identified a cutoff for anosmia at a score ≤ 0.7. This cutoff, which marks the 90th percentile of scores obtained with randomly ordered dilutions, had a balanced accuracy of 89% (78% to 97%) for detecting anosmia, comparable to traditional odor threshold assessments. Retest evaluations suggested a score difference of ±0.15 as a cutoff for clinically significant changes in olfactory function. In conclusion, the olfactory sorting test represents a simple, self-administered approach to the detection of anosmia or preserved olfactory function. With balanced accuracy similar to existing brief olfactory tests, this method offers a practical and user-friendly alternative for screening anosmia, addressing the need for resource-efficient assessments in clinical settings.</p>","PeriodicalId":9771,"journal":{"name":"Chemical Senses","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139943959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Evidence for parental environments profoundly influencing the physiology, biology, and neurobiology of future generations has been accumulating in the literature. Recent efforts to understand this phenomenon and its underlying mechanisms have sought to use species like rodents and insects to model multi-generational legacies of parental experiences like stress and nutritional exposures. From these studies, we have come to appreciate that parental exposure to salient environmental experiences impacts the cadence of brain development, hormonal responses to stress, and the expression of genes that govern cellular responses to stress in offspring. Recent studies using chemosensory exposure have emerged as a powerful tool to shed new light on how future generations come to be influenced by environments to which parents are exposed. With a specific focus on studies that have leveraged such use of salient chemosensory experiences, this review synthesizes our current understanding of the concept, causes, and consequences of the inheritance of chemosensory legacies by future generations and how this field of inquiry informs the larger picture of how parental experiences can influence offspring biology.
{"title":"Legacies of salient environmental experiences-insights from chemosensation.","authors":"Brian G Dias","doi":"10.1093/chemse/bjae002","DOIUrl":"10.1093/chemse/bjae002","url":null,"abstract":"<p><p>Evidence for parental environments profoundly influencing the physiology, biology, and neurobiology of future generations has been accumulating in the literature. Recent efforts to understand this phenomenon and its underlying mechanisms have sought to use species like rodents and insects to model multi-generational legacies of parental experiences like stress and nutritional exposures. From these studies, we have come to appreciate that parental exposure to salient environmental experiences impacts the cadence of brain development, hormonal responses to stress, and the expression of genes that govern cellular responses to stress in offspring. Recent studies using chemosensory exposure have emerged as a powerful tool to shed new light on how future generations come to be influenced by environments to which parents are exposed. With a specific focus on studies that have leveraged such use of salient chemosensory experiences, this review synthesizes our current understanding of the concept, causes, and consequences of the inheritance of chemosensory legacies by future generations and how this field of inquiry informs the larger picture of how parental experiences can influence offspring biology.</p>","PeriodicalId":9771,"journal":{"name":"Chemical Senses","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10825851/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139466413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Studies on taste bud cells and brain stem relay nuclei suggest that alternative pathways convey information regarding different taste qualities. Building on the hypothesis that amiloride (epithelial Na channel antagonist)-sensitive neurons respond to palatable salt (low-concentration) and amiloride-insensitive neurons respond to aversive salt (high-concentration), we investigated the histological distribution of taste-sensitive neurons in the rostral nucleus of the solitary tract in rats and their NaCl and amiloride sensitivities. We recorded neuronal activity in extracellular single units using multi-barrel glass micropipettes and reconstructed their locations on the rostrocaudal and mediolateral axes. Seventy-three taste-sensitive neurons were categorized into the best-taste category. The amiloride sensitivities of the 31 neurons were examined for 0.1, 0.2, 0.4, and 0.8 M NaCl. The neuronal distribution of amiloride-sensitive neurons was located in the lateral region, while amiloride-insensitive neurons were located in the medial region. The amiloride-sensitive neurons responded to low salt concentrations, signaling the NaCl levels required by body fluids. Amiloride-insensitive neurons were silent at low salt concentrations but may function as warning signals for high salt concentrations. Low-threshold and/or high-response neurons were located in the rostrolateral region. In contrast, high-threshold and/or low-response neurons were located in the caudal-medial region.
对味蕾细胞和脑干中继核的研究表明,不同的味觉质量有不同的信息传递途径。基于阿米洛利(上皮 Na 通道拮抗剂)敏感神经元对适口盐(低浓度)和阿米洛利不敏感神经元对厌恶盐(高浓度)反应的假设,我们研究了大鼠孤束喙核中味觉敏感神经元的组织学分布及其对 NaCl 和阿米洛利的敏感性。我们使用多管玻璃微量滴管记录了细胞外单个单元的神经元活动,并重建了它们在喙尾轴和内外侧轴上的位置。73个味觉敏感神经元被归入最佳味觉类别。对这 31 个神经元的阿米洛利敏感性进行了检测,检测浓度分别为 0.1、0.2、0.4 和 0.8 M NaCl。对阿米洛利敏感的神经元分布在外侧区域,而对阿米洛利不敏感的神经元分布在内侧区域。氨苯蝶啶敏感神经元对低盐浓度有反应,表明体液所需的氯化钠水平。氨苯蝶啶不敏感神经元在低盐浓度时保持沉默,但可能对高盐浓度起警示作用。低阈值和/或高反应神经元位于喙外侧区域。相反,高阈值和/或低反应神经元位于尾内侧区域。
{"title":"Different taste map for amiloride sensitivity, response frequency, and threshold to NaCl in the rostral nucleus of the solitary tract in rats.","authors":"Tatsuko Yokota, Katsunari Hiraba","doi":"10.1093/chemse/bjae036","DOIUrl":"10.1093/chemse/bjae036","url":null,"abstract":"<p><p>Studies on taste bud cells and brain stem relay nuclei suggest that alternative pathways convey information regarding different taste qualities. Building on the hypothesis that amiloride (epithelial Na channel antagonist)-sensitive neurons respond to palatable salt (low-concentration) and amiloride-insensitive neurons respond to aversive salt (high-concentration), we investigated the histological distribution of taste-sensitive neurons in the rostral nucleus of the solitary tract in rats and their NaCl and amiloride sensitivities. We recorded neuronal activity in extracellular single units using multi-barrel glass micropipettes and reconstructed their locations on the rostrocaudal and mediolateral axes. Seventy-three taste-sensitive neurons were categorized into the best-taste category. The amiloride sensitivities of the 31 neurons were examined for 0.1, 0.2, 0.4, and 0.8 M NaCl. The neuronal distribution of amiloride-sensitive neurons was located in the lateral region, while amiloride-insensitive neurons were located in the medial region. The amiloride-sensitive neurons responded to low salt concentrations, signaling the NaCl levels required by body fluids. Amiloride-insensitive neurons were silent at low salt concentrations but may function as warning signals for high salt concentrations. Low-threshold and/or high-response neurons were located in the rostrolateral region. In contrast, high-threshold and/or low-response neurons were located in the caudal-medial region.</p>","PeriodicalId":9771,"journal":{"name":"Chemical Senses","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142342558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Toxic puffers accumulate tetrodotoxin (TTX), a well-known neurotoxin, by feeding on TTX-bearing organisms and using it to defend themselves from predators. Our previous studies have demonstrated that toxic puffers are attracted to 5,6,11-trideoxytetrodotoxin (TDT), a nontoxic TTX analog that is simultaneously accumulated with TTX in toxic puffers and their prey. In addition, activity labeling using immunohistochemistry targeting neuronal activity marker suggests that TDT activates crypt olfactory sensory neurons (OSN) of the green spotted puffer. However, it remains to be determined whether individual crypt OSNs can physiologically respond to TDT. By employing electroporation to express GCaMP6s in OSNs, we successfully identified a distinct group of oval OSNs that exhibited a specific calcium response when exposed to TDT in green spotted puffers. These oval OSNs showed no response to amino acids (AAs), which serve as food odor cues for teleosts. Furthermore, oval morphology and surface positioning of TDT-sensitive OSNs in the olfactory epithelium closely resemble that of crypt OSNs. These findings further substantiate that TDT is specifically detected by crypt OSNs in green spotted puffer. The TDT odor may act as a chemoattractant for finding conspecific toxic puffers and for feeding TTX-bearing organisms for effective toxification.
{"title":"The odor of a nontoxic tetrodotoxin analog, 5,6,11-trideoxytetrodotoxin, is detected by specific olfactory sensory neurons of the green spotted puffers.","authors":"Takehisa Suzuki, Ryota Nakahigashi, Masaatsu Adachi, Toshio Nishikawa, Hideki Abe","doi":"10.1093/chemse/bjae021","DOIUrl":"10.1093/chemse/bjae021","url":null,"abstract":"<p><p>Toxic puffers accumulate tetrodotoxin (TTX), a well-known neurotoxin, by feeding on TTX-bearing organisms and using it to defend themselves from predators. Our previous studies have demonstrated that toxic puffers are attracted to 5,6,11-trideoxytetrodotoxin (TDT), a nontoxic TTX analog that is simultaneously accumulated with TTX in toxic puffers and their prey. In addition, activity labeling using immunohistochemistry targeting neuronal activity marker suggests that TDT activates crypt olfactory sensory neurons (OSN) of the green spotted puffer. However, it remains to be determined whether individual crypt OSNs can physiologically respond to TDT. By employing electroporation to express GCaMP6s in OSNs, we successfully identified a distinct group of oval OSNs that exhibited a specific calcium response when exposed to TDT in green spotted puffers. These oval OSNs showed no response to amino acids (AAs), which serve as food odor cues for teleosts. Furthermore, oval morphology and surface positioning of TDT-sensitive OSNs in the olfactory epithelium closely resemble that of crypt OSNs. These findings further substantiate that TDT is specifically detected by crypt OSNs in green spotted puffer. The TDT odor may act as a chemoattractant for finding conspecific toxic puffers and for feeding TTX-bearing organisms for effective toxification.</p>","PeriodicalId":9771,"journal":{"name":"Chemical Senses","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11258809/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141070159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eleonora M C Trecca, Pier Gerardo Marano, Ferruccio Madaro, Francesca Fortunato, Daniela R Frisotti, Vito Carlo Alberto Caponio, Matteo Vocale, Michele Cassano
Only a few studies have investigated olfactory function in patients with obstructive sleep apnea syndrome (OSAS) using psychophysical testing, and there is a scarcity of data regarding taste evaluation in the existing literature. The primary objectives of this study were to assess both smell and taste in patients with OSAS and to explore the correlation between the severity of symptoms and sensory perception. A total of 85 OSAS patients and a control group comprising 81 subjects were enrolled. Initial assessments included anamnesis, nasal endoscopy, and the completion of questionnaires (Epworth Sleepiness Scale, Visual Analogue Scale, Questionnaire of Olfactory Disorders, and the importance of olfaction questionnaire). The diagnosis of OSAS was confirmed by polysomnography, while nasal airflow was evaluated using rhinomanometry. Olfaction was assessed using the Sniffin' Sticks test, and the Threshold-Discrimination-Identification (TDI) score was calculated. Taste evaluation was conducted in a subgroup of participants (42 patients, 38 controls) using taste strips. The mean TDI score was 31 ± 5.6 for OSAS patients and 35 ± 4.6 for controls, indicating a significant difference (P < 0.001). Similarly, the taste score was 7 ± 3.0 for OSAS patients and 12.6 ± 3.2 for controls (P < 0.001). No correlations were observed between TDI and Apnea Hypopnea Index (AHI) (r = -0.12; P = 0.28), as well as between the taste score and AHI (r = -0.31; P = 0.22). However, a weak but significant correlation between TDI score and Epworth Sleepiness Scale was detected (r = -0.05; P = 0.002). The study revealed a significant decrease in sensory perception among patients with OSAS, though open questions persist about the pathophysiology.
{"title":"Impact of obstructive sleep apnea syndrome on olfactory and gustatory capacity.","authors":"Eleonora M C Trecca, Pier Gerardo Marano, Ferruccio Madaro, Francesca Fortunato, Daniela R Frisotti, Vito Carlo Alberto Caponio, Matteo Vocale, Michele Cassano","doi":"10.1093/chemse/bjae022","DOIUrl":"10.1093/chemse/bjae022","url":null,"abstract":"<p><p>Only a few studies have investigated olfactory function in patients with obstructive sleep apnea syndrome (OSAS) using psychophysical testing, and there is a scarcity of data regarding taste evaluation in the existing literature. The primary objectives of this study were to assess both smell and taste in patients with OSAS and to explore the correlation between the severity of symptoms and sensory perception. A total of 85 OSAS patients and a control group comprising 81 subjects were enrolled. Initial assessments included anamnesis, nasal endoscopy, and the completion of questionnaires (Epworth Sleepiness Scale, Visual Analogue Scale, Questionnaire of Olfactory Disorders, and the importance of olfaction questionnaire). The diagnosis of OSAS was confirmed by polysomnography, while nasal airflow was evaluated using rhinomanometry. Olfaction was assessed using the Sniffin' Sticks test, and the Threshold-Discrimination-Identification (TDI) score was calculated. Taste evaluation was conducted in a subgroup of participants (42 patients, 38 controls) using taste strips. The mean TDI score was 31 ± 5.6 for OSAS patients and 35 ± 4.6 for controls, indicating a significant difference (P < 0.001). Similarly, the taste score was 7 ± 3.0 for OSAS patients and 12.6 ± 3.2 for controls (P < 0.001). No correlations were observed between TDI and Apnea Hypopnea Index (AHI) (r = -0.12; P = 0.28), as well as between the taste score and AHI (r = -0.31; P = 0.22). However, a weak but significant correlation between TDI score and Epworth Sleepiness Scale was detected (r = -0.05; P = 0.002). The study revealed a significant decrease in sensory perception among patients with OSAS, though open questions persist about the pathophysiology.</p>","PeriodicalId":9771,"journal":{"name":"Chemical Senses","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141178985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ryan M Wood, Erin L Vasquez, Krystal A Goyins, Eduardo Gutierrez Kuri, Kevin Connelly, Saima Humayun, Lindsey J Macpherson
Many common chemotherapeutics produce disruptions in the sense of taste which can lead to loss of appetite, nutritional imbalance, and reduced quality of life, especially if taste loss persists after treatment ends. Cyclophosphamide (CYP), an alkylating chemotherapeutic agent, affects taste sensitivity through its cytotoxic effects on mature taste receptor cells (TRCs) and on taste progenitor cell populations, retarding the capacity to replace TRCs. Mechanistic studies have focused primarily on taste cells, however, taste signaling requires communication between TRCs and the gustatory nerve fibers that innervate them. Here, we evaluate cyclophosphamide's effects on the peripheral gustatory nerve fibers that innervate the taste buds. Following histological analysis of tongue tissues, we find that CYP reduces innervation within the fungiform and circumvallates taste buds within 4 days after administration. To better understand the dynamics of the denervation process, we used 2-photon intravital imaging to visualize the peripheral gustatory nerve fibers within individual fungiform taste buds up to 20 days after CYP treatment. We find that gustatory fibers retract from the taste bud properly but are maintained within the central papilla core. These data indicate that in addition to TRCs, gustatory nerve fibers are also affected by CYP treatment. Because the connectivity between TRCs and gustatory neurons must be re-established for proper function, gustatory fibers should continue to be included in future studies to understand the mechanisms leading to chemotherapy-induced persistent taste loss.
{"title":"Cyclophosphamide induces the loss of taste bud innervation in mice.","authors":"Ryan M Wood, Erin L Vasquez, Krystal A Goyins, Eduardo Gutierrez Kuri, Kevin Connelly, Saima Humayun, Lindsey J Macpherson","doi":"10.1093/chemse/bjae010","DOIUrl":"10.1093/chemse/bjae010","url":null,"abstract":"<p><p>Many common chemotherapeutics produce disruptions in the sense of taste which can lead to loss of appetite, nutritional imbalance, and reduced quality of life, especially if taste loss persists after treatment ends. Cyclophosphamide (CYP), an alkylating chemotherapeutic agent, affects taste sensitivity through its cytotoxic effects on mature taste receptor cells (TRCs) and on taste progenitor cell populations, retarding the capacity to replace TRCs. Mechanistic studies have focused primarily on taste cells, however, taste signaling requires communication between TRCs and the gustatory nerve fibers that innervate them. Here, we evaluate cyclophosphamide's effects on the peripheral gustatory nerve fibers that innervate the taste buds. Following histological analysis of tongue tissues, we find that CYP reduces innervation within the fungiform and circumvallates taste buds within 4 days after administration. To better understand the dynamics of the denervation process, we used 2-photon intravital imaging to visualize the peripheral gustatory nerve fibers within individual fungiform taste buds up to 20 days after CYP treatment. We find that gustatory fibers retract from the taste bud properly but are maintained within the central papilla core. These data indicate that in addition to TRCs, gustatory nerve fibers are also affected by CYP treatment. Because the connectivity between TRCs and gustatory neurons must be re-established for proper function, gustatory fibers should continue to be included in future studies to understand the mechanisms leading to chemotherapy-induced persistent taste loss.</p>","PeriodicalId":9771,"journal":{"name":"Chemical Senses","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10929424/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139989447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anupa Ekanayake, Senal Peiris, Sangam Kanekar, Michael Tobia, Qing Yang, Biyar Ahmed, Silas McCaslin, Deepak Kalra, Paul Eslinger, Prasanna Karunanayaka
The olfactory nerve, also known as cranial nerve I, is known to have exclusive ipsilateral projections to primary olfactory cortical structures. However, the lateralization of olfactory processes is known to depend on the task and nature of stimuli. It still remains unclear whether olfactory system projections in humans also correspond to functional pathways during olfactory tasks without any trigeminal, perceptual, or cognitive-motor components. Twenty young healthy subjects with a normal sense of smell took part in an olfactory functional magnetic resonance imaging (fMRI) study. We used 2 types of nostril-specific stimulation, passive (no sniffing), and active (with sniffing), with phenyl ethyl alcohol, a pure olfactory stimulant, to investigate fMRI activity patterns in primary and secondary olfactory-related brain structures. Irrespective of the stimulated nostril and the type of stimulation, we detected symmetrical activity in primary and secondary olfactory-related brain structures such as the primary olfactory cortex, entorhinal cortex, and orbitofrontal cortex. In the absence of perceptual or cognitive-motor task demands, the perception of monorhinally presented pure odors is processed bilaterally in the brain.
{"title":"Monorhinal and birhinal odor processing in humans: an fMRI investigation.","authors":"Anupa Ekanayake, Senal Peiris, Sangam Kanekar, Michael Tobia, Qing Yang, Biyar Ahmed, Silas McCaslin, Deepak Kalra, Paul Eslinger, Prasanna Karunanayaka","doi":"10.1093/chemse/bjae038","DOIUrl":"10.1093/chemse/bjae038","url":null,"abstract":"<p><p>The olfactory nerve, also known as cranial nerve I, is known to have exclusive ipsilateral projections to primary olfactory cortical structures. However, the lateralization of olfactory processes is known to depend on the task and nature of stimuli. It still remains unclear whether olfactory system projections in humans also correspond to functional pathways during olfactory tasks without any trigeminal, perceptual, or cognitive-motor components. Twenty young healthy subjects with a normal sense of smell took part in an olfactory functional magnetic resonance imaging (fMRI) study. We used 2 types of nostril-specific stimulation, passive (no sniffing), and active (with sniffing), with phenyl ethyl alcohol, a pure olfactory stimulant, to investigate fMRI activity patterns in primary and secondary olfactory-related brain structures. Irrespective of the stimulated nostril and the type of stimulation, we detected symmetrical activity in primary and secondary olfactory-related brain structures such as the primary olfactory cortex, entorhinal cortex, and orbitofrontal cortex. In the absence of perceptual or cognitive-motor task demands, the perception of monorhinally presented pure odors is processed bilaterally in the brain.</p>","PeriodicalId":9771,"journal":{"name":"Chemical Senses","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142388381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eva Tolomeo, Carla Masala, Antonio Aversa, Giancarlo Ottaviano, Flavia Gasperi, Leonardo Menghi, Valentina Parma, Marco Tullio Liuzza
A common tool to measure olfactory function is the Sniffin' Sticks Test extended version (SSET). The SSET evaluates olfactory ability by summing the scores of three subtests: Threshold, Discrimination, and Identification. Recent meta-scientific literature revealed that many psychometric instruments currently in use have not been adequately validated, leading to a measurement crisis that raises concerns about the validity of the conclusions drawn with these instruments. Two examples of the measurement crisis are (i) the use of sum scores without testing their assumptions (e.g. unidimensionality and tau-equivalence), which indicate that all subtests have the same, stable relationship with their underlying construct, and (ii) the lack of assessment of measurement invariance across groups. Here, we aim to investigate the unidimensionality and tau-equivalence assumptions, internal consistency, and measurement invariance of sex and age groups of the SSET. We tested 988 (555 females, mean ± SD: 39.75 ± 18.60 years) participants with the Italian version of the SSET. The tau-equivalent model demonstrated excellent fit indices (CFI robust = 1, TLI robust = 1, RMSEA robust = 0, SRMR = 0.013), which best explain the data, indicating that all subtests are equally important in measuring olfactory function, but not necessarily equally precise. The results also revealed full measurement invariance across age groups and configural, partial metric, and scalar invariance across sexes, indicating that the use of latent means to compare sex groups should be chosen over raw scores. However, the SSET demonstrated moderate internal consistency. Future studies should clarify whether the reliability of the SSET can be increased.
{"title":"Psychometric validity of the sum score of the Sniffin' Sticks-Extended Test.","authors":"Eva Tolomeo, Carla Masala, Antonio Aversa, Giancarlo Ottaviano, Flavia Gasperi, Leonardo Menghi, Valentina Parma, Marco Tullio Liuzza","doi":"10.1093/chemse/bjae032","DOIUrl":"10.1093/chemse/bjae032","url":null,"abstract":"<p><p>A common tool to measure olfactory function is the Sniffin' Sticks Test extended version (SSET). The SSET evaluates olfactory ability by summing the scores of three subtests: Threshold, Discrimination, and Identification. Recent meta-scientific literature revealed that many psychometric instruments currently in use have not been adequately validated, leading to a measurement crisis that raises concerns about the validity of the conclusions drawn with these instruments. Two examples of the measurement crisis are (i) the use of sum scores without testing their assumptions (e.g. unidimensionality and tau-equivalence), which indicate that all subtests have the same, stable relationship with their underlying construct, and (ii) the lack of assessment of measurement invariance across groups. Here, we aim to investigate the unidimensionality and tau-equivalence assumptions, internal consistency, and measurement invariance of sex and age groups of the SSET. We tested 988 (555 females, mean ± SD: 39.75 ± 18.60 years) participants with the Italian version of the SSET. The tau-equivalent model demonstrated excellent fit indices (CFI robust = 1, TLI robust = 1, RMSEA robust = 0, SRMR = 0.013), which best explain the data, indicating that all subtests are equally important in measuring olfactory function, but not necessarily equally precise. The results also revealed full measurement invariance across age groups and configural, partial metric, and scalar invariance across sexes, indicating that the use of latent means to compare sex groups should be chosen over raw scores. However, the SSET demonstrated moderate internal consistency. Future studies should clarify whether the reliability of the SSET can be increased.</p>","PeriodicalId":9771,"journal":{"name":"Chemical Senses","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142104738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}