Pub Date : 2025-09-01Epub Date: 2025-07-05DOI: 10.1016/j.neures.2025.104932
Hiroki Uno , Takahide Itokazu , Toshihide Yamashita
Cognitive impairment is a significant complication of diabetes. Although the detailed mechanism remains unclear, prolonged neuroinflammation mediated by microglia is recognized as a key contributor to neural dysfunction. Recent studies have shown that Formyl peptide receptor 1 (FPR1), a G protein-coupled chemoattractant receptor, plays a role in microglial activation and brain pathology. However, the involvement of FPR2, another isoform within the FPR family, in microglial activation and cognitive decline has not yet been explored. In this study, we observed an increased expression of FPR2 in microglia within the hippocampus of type 2 diabetes (db/db) mice. Furthermore, we demonstrated that intracerebroventricular administration of WRW4, a selective FPR2 antagonist, alleviates diabetes-related cognitive decline. Histological analysis revealed that WRW4 treatment mitigates morphological alteration and upregulation of a phagocytic marker (CD68) of the microglia in the hippocampus of db/db mice. These results indicate that FPR2 plays a critical role in inducing diabetes-related microglial phenotype. These findings highlight the therapeutic potential of FPR2 signal inhibition as a novel strategy to mitigate cognitive decline associated with diabetes.
{"title":"Formyl peptide receptor 2 antagonist WRW4 ameliorates diabetes-induced cognitive decline in mice","authors":"Hiroki Uno , Takahide Itokazu , Toshihide Yamashita","doi":"10.1016/j.neures.2025.104932","DOIUrl":"10.1016/j.neures.2025.104932","url":null,"abstract":"<div><div>Cognitive impairment is a significant complication of diabetes. Although the detailed mechanism remains unclear, prolonged neuroinflammation mediated by microglia is recognized as a key contributor to neural dysfunction. Recent studies have shown that Formyl peptide receptor 1 (FPR1), a G protein-coupled chemoattractant receptor, plays a role in microglial activation and brain pathology. However, the involvement of FPR2, another isoform within the FPR family, in microglial activation and cognitive decline has not yet been explored. In this study, we observed an increased expression of FPR2 in microglia within the hippocampus of type 2 diabetes (db/db) mice. Furthermore, we demonstrated that intracerebroventricular administration of WRW4, a selective FPR2 antagonist, alleviates diabetes-related cognitive decline. Histological analysis revealed that WRW4 treatment mitigates morphological alteration and upregulation of a phagocytic marker (CD68) of the microglia in the hippocampus of db/db mice. These results indicate that FPR2 plays a critical role in inducing diabetes-related microglial phenotype. These findings highlight the therapeutic potential of FPR2 signal inhibition as a novel strategy to mitigate cognitive decline associated with diabetes.</div></div>","PeriodicalId":19146,"journal":{"name":"Neuroscience Research","volume":"218 ","pages":"Article 104932"},"PeriodicalIF":2.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144575930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-01Epub Date: 2025-06-28DOI: 10.1016/j.neures.2025.104929
Yumi Hamasaki, Masabumi Minami, Taiju Amano
The central part of the mouse medial preoptic area (cMPOA) is involved in parental behavior because the neurotoxic lesion of the cMPOA disturbed parental behavior and switched to infanticidal behavior. The cMPOA receives projection from many brain regions, including the medial amygdala (Me). We have previously found that optogenetic inhibition of the projection pathway from the Me to the cMPOA in virgin male mice suppressed the infanticidal behavior of virgin mice toward pups. Furthermore, electrophysiological analysis has revealed that intracellular signaling-mediated disinhibition occurs in the cMPOA neurons during the transition from virgin to father in gestation experience (FGE) mice. However, the specific downstream signal transduction pathway remains unclear. In this study, we utilized U0126, a MEK1/2 inhibitor, because U0126 has been reported to modulate GABAergic currents. Therefore, we examined the contribution of U0126 at the synaptic and behavioral levels. Applying U0126 to the cMPOA neurons in FGE mice restored eIPSP as much as that in cMPOA neurons in virgin mice. Furthermore, microinfusion of U0126 into the cMPOA shifted the behavioral pattern of FGE mice toward infanticide. These changes were not observed in the mice that experienced parenting. The results suggest that MEK1/2 mediates neurotransmission in the cMPOA and contributes to the stage transition from virgin to FGE mice after mating with females.
{"title":"Effects of MEK1/2 blocker U0126 on the medial preoptic synapse and behavioral selection of male mice","authors":"Yumi Hamasaki, Masabumi Minami, Taiju Amano","doi":"10.1016/j.neures.2025.104929","DOIUrl":"10.1016/j.neures.2025.104929","url":null,"abstract":"<div><div>The central part of the mouse medial preoptic area (cMPOA) is involved in parental behavior because the neurotoxic lesion of the cMPOA disturbed parental behavior and switched to infanticidal behavior. The cMPOA receives projection from many brain regions, including the medial amygdala (Me). We have previously found that optogenetic inhibition of the projection pathway from the Me to the cMPOA in virgin male mice suppressed the infanticidal behavior of virgin mice toward pups. Furthermore, electrophysiological analysis has revealed that intracellular signaling-mediated disinhibition occurs in the cMPOA neurons during the transition from virgin to father in gestation experience (FGE) mice. However, the specific downstream signal transduction pathway remains unclear. In this study, we utilized U0126, a MEK1/2 inhibitor, because U0126 has been reported to modulate GABAergic currents. Therefore, we examined the contribution of U0126 at the synaptic and behavioral levels. Applying U0126 to the cMPOA neurons in FGE mice restored eIPSP as much as that in cMPOA neurons in virgin mice. Furthermore, microinfusion of U0126 into the cMPOA shifted the behavioral pattern of FGE mice toward infanticide. These changes were not observed in the mice that experienced parenting. The results suggest that MEK1/2 mediates neurotransmission in the cMPOA and contributes to the stage transition from virgin to FGE mice after mating with females.</div></div>","PeriodicalId":19146,"journal":{"name":"Neuroscience Research","volume":"218 ","pages":"Article 104929"},"PeriodicalIF":2.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144529024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-01Epub Date: 2025-06-13DOI: 10.1016/j.neures.2025.104923
Nanami Kasakura, Yuka Murata, Kanzo Suzuki, Eri Segi-Nishida
Neurotrophin-3 (NT-3) is a neurotrophic factor that regulates neuronal differentiation and synaptic plasticity. In the adult central nervous system, NT-3 is predominantly expressed in the hippocampal dentate gyrus (DG). Chronic antidepressant treatment suppresses Ntf3 expression in the DG; however, its functional significance remains unclear. To investigate the role of NT-3 in the adult DG, an adeno-associated virus (AAV)-mediated knockdown system was employed in mice. Immunohistochemical analysis revealed that TrkC, the high-affinity receptor for NT-3, was highly expressed in the DG. Under basal conditions, NT-3 knockdown significantly reduced the expression of FosB, an activity-dependent marker. Gene expression analysis showed that Arc, Egr1, and Fosb expressions were also significantly decreased. Although NT-3 knockdown did not affect cell proliferation in the DG, it impaired dendritic elongation in immature neurons. Additionally, NT-3 knockdown significantly reduced Npy expression. These findings suggest that endogenous NT-3 in the adult DG regulates both basal neuronal activity and newborn neuronal differentiation, contributing to hippocampal homeostasis. Further research is required to determine whether NT-3 downregulation induced by chronic antidepressant treatment influences neuronal activity and hippocampal plasticity in neuropsychiatric conditions.
{"title":"Role of endogenous NT-3 in neuronal activity and neurogenesis in the hippocampal dentate gyrus","authors":"Nanami Kasakura, Yuka Murata, Kanzo Suzuki, Eri Segi-Nishida","doi":"10.1016/j.neures.2025.104923","DOIUrl":"10.1016/j.neures.2025.104923","url":null,"abstract":"<div><div>Neurotrophin-3 (NT-3) is a neurotrophic factor that regulates neuronal differentiation and synaptic plasticity. In the adult central nervous system, NT-3 is predominantly expressed in the hippocampal dentate gyrus (DG). Chronic antidepressant treatment suppresses <em>Ntf3</em> expression in the DG; however, its functional significance remains unclear. To investigate the role of NT-3 in the adult DG, an adeno-associated virus (AAV)-mediated knockdown system was employed in mice. Immunohistochemical analysis revealed that TrkC, the high-affinity receptor for NT-3, was highly expressed in the DG. Under basal conditions, NT-3 knockdown significantly reduced the expression of FosB, an activity-dependent marker. Gene expression analysis showed that <em>Arc</em>, <em>Egr1</em>, and <em>Fosb</em> expressions were also significantly decreased. Although NT-3 knockdown did not affect cell proliferation in the DG, it impaired dendritic elongation in immature neurons. Additionally, NT-3 knockdown significantly reduced <em>Npy</em> expression. These findings suggest that endogenous NT-3 in the adult DG regulates both basal neuronal activity and newborn neuronal differentiation, contributing to hippocampal homeostasis. Further research is required to determine whether NT-3 downregulation induced by chronic antidepressant treatment influences neuronal activity and hippocampal plasticity in neuropsychiatric conditions.</div></div>","PeriodicalId":19146,"journal":{"name":"Neuroscience Research","volume":"218 ","pages":"Article 104923"},"PeriodicalIF":2.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the ventral part of the caudal striatum, the direct and indirect pathway neurons are unevenly distributed, forming zones with a paucity of neurons with dopamine receptor 1 (D1R) or dopamine receptor 2 (D2R), referred as D1R- or D2R-poor zone (D1pz or D2pz, respectively). This contrasts with their uniform distribution in other striatal regions. A key question is whether D1pz and D2pz function as a unit or independently. Since the striatum requires afferent excitatory inputs for activation, investigating biased excitatory inputs to the caudal striatum is essential. Our findings indicate that vesicular glutamate transporter 2 (VGluT2) was concentrated in D2pz, suggesting biased excitatory innervation. Retrograde tracer labeling identified potential sources of subcortical glutamatergic projections. Projection from the paraventricular nucleus of the thalamus (PVT) was visualized using VGluT2-Cre mice. PVT preferentially projected to the ventral caudal region in the striatum. Quantitative analysis of PVT axons revealed preferential localization in the D2pz, with fewer axons in the D1pz. The substantia nigra pars lateralis, innervated by the caudal striatum, did not project to the PVT, suggesting the caudal striatum and PVT may not form a part of the cortico-basal ganglia-thalamic loop. These results imply that D1pz and D2pz may be differentially activated by PVT inputs, selectively recruiting direct pathways.
{"title":"Biased thalamic innervation onto the distinct subregion where dopamine receptor 1 is dominantly expressed in the caudal striatum","authors":"Fuko Kadono , Jingqi Wang , Kenta Kobayashi , Fuyuki Karube , Fumino Fujiyama","doi":"10.1016/j.neures.2025.104930","DOIUrl":"10.1016/j.neures.2025.104930","url":null,"abstract":"<div><div>In the ventral part of the caudal striatum, the direct and indirect pathway neurons are unevenly distributed, forming zones with a paucity of neurons with dopamine receptor 1 (D1R) or dopamine receptor 2 (D2R), referred as D1R- or D2R-poor zone (D1pz or D2pz, respectively). This contrasts with their uniform distribution in other striatal regions. A key question is whether D1pz and D2pz function as a unit or independently. Since the striatum requires afferent excitatory inputs for activation, investigating biased excitatory inputs to the caudal striatum is essential. Our findings indicate that vesicular glutamate transporter 2 (VGluT2) was concentrated in D2pz, suggesting biased excitatory innervation. Retrograde tracer labeling identified potential sources of subcortical glutamatergic projections. Projection from the paraventricular nucleus of the thalamus (PVT) was visualized using VGluT2-Cre mice. PVT preferentially projected to the ventral caudal region in the striatum. Quantitative analysis of PVT axons revealed preferential localization in the D2pz, with fewer axons in the D1pz. The substantia nigra pars lateralis, innervated by the caudal striatum, did not project to the PVT, suggesting the caudal striatum and PVT may not form a part of the cortico-basal ganglia-thalamic loop. These results imply that D1pz and D2pz may be differentially activated by PVT inputs, selectively recruiting direct pathways.</div></div>","PeriodicalId":19146,"journal":{"name":"Neuroscience Research","volume":"218 ","pages":"Article 104930"},"PeriodicalIF":2.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144554023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-01Epub Date: 2025-06-14DOI: 10.1016/j.neures.2025.104924
Rabia Garibağaoğlu, Riho Kobayashi , Victoria Hanashiro, Jun Tomita, Kazuhiko Kume
Sleep and nutrition are important for the survival of organisms. This study focuses on the effects of amino acids, specifically L-alanine, on sleep of Drosophila melanogaster. Some amino acids including L-alanine are shown to be attractive to flies. To assess their effect on sleep, either sucrose (sweet) or sorbitol (non-sweet) was used as a base sugar of the food. Sleep was measured using monitors with infrared beams, and feeding behavior was examined by food intake and proboscis extension response tests. L-alanine supplementation in a sweet diet did not alter sleep, but supplementation in a non-sweet diet increased sleep. The addition of non-nutritive sweetener, sucralose to a non-sweet diet also increased sleep, but combining sucralose with L-alanine did not produce additive effects. L-alanine also increased the lifespan of aged flies when supplemented in a non-sweet diet. These findings suggest that the attractive taste properties of L-alanine induced sleep and offer new insights into the relationship between sleep and taste.
{"title":"The effect of L-alanine on sleep through taste properties in Drosophila melanogaster","authors":"Rabia Garibağaoğlu, Riho Kobayashi , Victoria Hanashiro, Jun Tomita, Kazuhiko Kume","doi":"10.1016/j.neures.2025.104924","DOIUrl":"10.1016/j.neures.2025.104924","url":null,"abstract":"<div><div>Sleep and nutrition are important for the survival of organisms. This study focuses on the effects of amino acids, specifically L-alanine, on sleep of <em>Drosophila melanogaster</em>. Some amino acids including L-alanine are shown to be attractive to flies. To assess their effect on sleep, either sucrose (sweet) or sorbitol (non-sweet) was used as a base sugar of the food. Sleep was measured using monitors with infrared beams, and feeding behavior was examined by food intake and proboscis extension response tests. L-alanine supplementation in a sweet diet did not alter sleep, but supplementation in a non-sweet diet increased sleep. The addition of non-nutritive sweetener, sucralose to a non-sweet diet also increased sleep, but combining sucralose with L-alanine did not produce additive effects. L-alanine also increased the lifespan of aged flies when supplemented in a non-sweet diet. These findings suggest that the attractive taste properties of L-alanine induced sleep and offer new insights into the relationship between sleep and taste.</div></div>","PeriodicalId":19146,"journal":{"name":"Neuroscience Research","volume":"218 ","pages":"Article 104924"},"PeriodicalIF":2.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anorexia nervosa (AN) is an eating disorder characterized by restricted energy intake, severely underweight status, and frequent hyperactivity. Previous research has shown structural and functional alterations in the medial prefrontal cortex (mPFC) and hippocampus of AN patients. To investigate the pathological mechanism of AN, we analyzed the expression and distribution of parvalbumin (PV) interneurons and perineuronal nets (PNNs), which are implicated in the pathology of neuropsychiatric disorders, in the mPFC and hippocampus dorsal (HPCd) and ventral (HPCv) using an activity-based anorexia (ABA) mouse model. We found that PNN expression and density increased in the mPFC, with minor alterations in the HPCd and HPCv of ABA mice. The expression and distribution of PV neurons were unchanged in the brains of ABA mice, except for a regional decrease in PV-expressing neuron density in the HPCd. Co-localization analysis showed an increased number of PNNs enwrapping PV-negative neurons in the mPFC of ABA mice. Furthermore, the upregulation of PNN expression in the mPFC was positively correlated with elevated blood corticosterone levels, a well-known stress indicator, in ABA mice. Our findings suggest that the increased expression and distribution of PNNs surrounding PV-negative neurons in the mPFC may indicate the pathological mechanisms of AN.
{"title":"Alteration of perineuronal nets and parvalbumin interneurons in prefrontal cortex and hippocampus, and correlation with blood corticosterone in activity-based anorexia model mice","authors":"Hoang Duy Nguyen , Haruko Miyazaki , Hiroki Kawai , Ziyi Wang , Shinji Sakamoto , Manabu Takaki , Toshitaka Oohashi","doi":"10.1016/j.neures.2025.104922","DOIUrl":"10.1016/j.neures.2025.104922","url":null,"abstract":"<div><div>Anorexia nervosa (AN) is an eating disorder characterized by restricted energy intake, severely underweight status, and frequent hyperactivity. Previous research has shown structural and functional alterations in the medial prefrontal cortex (mPFC) and hippocampus of AN patients. To investigate the pathological mechanism of AN, we analyzed the expression and distribution of parvalbumin (PV) interneurons and perineuronal nets (PNNs), which are implicated in the pathology of neuropsychiatric disorders, in the mPFC and hippocampus dorsal (HPCd) and ventral (HPCv) using an activity-based anorexia (ABA) mouse model. We found that PNN expression and density increased in the mPFC, with minor alterations in the HPCd and HPCv of ABA mice. The expression and distribution of PV neurons were unchanged in the brains of ABA mice, except for a regional decrease in PV-expressing neuron density in the HPCd. Co-localization analysis showed an increased number of PNNs enwrapping PV-negative neurons in the mPFC of ABA mice. Furthermore, the upregulation of PNN expression in the mPFC was positively correlated with elevated blood corticosterone levels, a well-known stress indicator, in ABA mice. Our findings suggest that the increased expression and distribution of PNNs surrounding PV-negative neurons in the mPFC may indicate the pathological mechanisms of AN.</div></div>","PeriodicalId":19146,"journal":{"name":"Neuroscience Research","volume":"218 ","pages":"Article 104922"},"PeriodicalIF":2.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144310182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-01Epub Date: 2025-06-21DOI: 10.1016/j.neures.2025.104926
Junyu Liu , Akihiro Goto , Yasunori Hayashi
{"title":"Corrigendum to “Time-window of offline long-term potentiation in anterior cingulate cortex during memory consolidation and recall” [Neurosci. Res. 212 (2025) 75–83]","authors":"Junyu Liu , Akihiro Goto , Yasunori Hayashi","doi":"10.1016/j.neures.2025.104926","DOIUrl":"10.1016/j.neures.2025.104926","url":null,"abstract":"","PeriodicalId":19146,"journal":{"name":"Neuroscience Research","volume":"217 ","pages":"Article 104926"},"PeriodicalIF":2.4,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We recently found a loss of function mosaic mutation of KMT2C, a causative gene for autism spectrum disorder and Kleefstra syndrome, in a patient with bipolar disorder and reported that somatic mutations in neurodevelopmental disorder-related genes are increased in bipolar disorder by deep exome sequencing analysis. However, causal roles of neurodevelopmental disorder-related mutations in bipolar disorder, a qualitatively different mental disorder, are not known. In this study, we focused on a loss of function mutation of Kmt2c, that causes autism-like phenotypes in mice. To simulate a mosaic mutation found in the patient, we generated mosaic Kmt2c knockout mice using conventional chimera mice technology. We showed that the mosaic Kmt2c knockout mice did not show autism-like behavior but presented anxiety disorder-like symptom, which is avoidance to a corner where the mice previously experienced air puff. The rate of depression-like episodes measured by wheel running recording did not differ from control mosaic mice. These results suggest that mosaic mutations of neurodevelopmental disorder-related genes can cause qualitatively different anxiety disorder-like phenotypes. Because anxiety is one of symptomatic spectrum of bipolar disorder, these findings support the role of mosaic mutations of neurodevelopmental disorder-related genes as a component of the genetic architecture of bipolar disorder.
{"title":"Possible role of mosaic mutations of neurodevelopmental disorder-related genes in bipolar disorder: Lessons from Kmt2c chimeric heterozygous knockout mice","authors":"Takumi Nakamura , Kazuo Nakajima , Noriko Fujimori-Tonou , Takaoki Kasahara , Takashi Tsuboi , Tadafumi Kato","doi":"10.1016/j.neures.2025.05.005","DOIUrl":"10.1016/j.neures.2025.05.005","url":null,"abstract":"<div><div>We recently found a loss of function mosaic mutation of <em>KMT2C</em>, a causative gene for autism spectrum disorder and Kleefstra syndrome, in a patient with bipolar disorder and reported that somatic mutations in neurodevelopmental disorder-related genes are increased in bipolar disorder by deep exome sequencing analysis. However, causal roles of neurodevelopmental disorder-related mutations in bipolar disorder, a qualitatively different mental disorder, are not known. In this study, we focused on a loss of function mutation of <em>Kmt2c</em>, that causes autism-like phenotypes in mice. To simulate a mosaic mutation found in the patient, we generated mosaic <em>Kmt2c</em> knockout mice using conventional chimera mice technology. We showed that the mosaic <em>Kmt2c</em> knockout mice did not show autism-like behavior but presented anxiety disorder-like symptom, which is avoidance to a corner where the mice previously experienced air puff. The rate of depression-like episodes measured by wheel running recording did not differ from control mosaic mice. These results suggest that mosaic mutations of neurodevelopmental disorder-related genes can cause qualitatively different anxiety disorder-like phenotypes. Because anxiety is one of symptomatic spectrum of bipolar disorder, these findings support the role of mosaic mutations of neurodevelopmental disorder-related genes as a component of the genetic architecture of bipolar disorder.</div></div>","PeriodicalId":19146,"journal":{"name":"Neuroscience Research","volume":"217 ","pages":"Article 104910"},"PeriodicalIF":2.4,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144142845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hippocampal neurons fire synchronously in a population at low frequencies and burst individually at high frequencies, with synaptic plasticity thought to depend on the interplay of these firing patterns. This study investigated synaptic plasticity in the hippocampal CA1 region induced by synaptic input with bursts superimposed on low-frequency rhythms. Low-frequency stimulation (LFS) was varied from 0.5 to 5 Hz, and various numbers of bursts (3–1000) consisting of 2–4 pulses at 100 Hz were superimposed on LFS. The patterned stimuli with 1-Hz LFS effectively induced synaptic plasticity. The direction and magnitude of plasticity depended on the number of bursts. We identified key roles for adenosine A1 receptors and GABAergic signaling in regulating synaptic plasticity. The blockade of adenosine A1 receptors increased the magnitude of long-term potentiation induced by specific burst patterns and differentially affected synaptic plasticity induced by 1-Hz LFS. Through its interactions with hippocampal rhythms and inhibitory circuits, adenosine elevated extracellularly during conditioning stimuli regulated the magnitude and direction of synaptic plasticity. This study proposes hypotheses for the role of adenosine in the modulation of synaptic plasticity, which maintains the balance between potentiation and depression in hippocampal circuits.
{"title":"Synaptic plasticity induced by CA1 synaptic input with bursts superimposed on low-frequency rhythms","authors":"Satoshi Fujii , Yoshihiko Yamazaki , Hiroki Fujiwara , Jun-Ichi Goto , Takeo Watanabe , Katsuhiko Mikoshiba","doi":"10.1016/j.neures.2025.104913","DOIUrl":"10.1016/j.neures.2025.104913","url":null,"abstract":"<div><div>Hippocampal neurons fire synchronously in a population at low frequencies and burst individually at high frequencies, with synaptic plasticity thought to depend on the interplay of these firing patterns. This study investigated synaptic plasticity in the hippocampal CA1 region induced by synaptic input with bursts superimposed on low-frequency rhythms. Low-frequency stimulation (LFS) was varied from 0.5 to 5 Hz, and various numbers of bursts (3–1000) consisting of 2–4 pulses at 100 Hz were superimposed on LFS. The patterned stimuli with 1-Hz LFS effectively induced synaptic plasticity. The direction and magnitude of plasticity depended on the number of bursts. We identified key roles for adenosine A<sub>1</sub> receptors and GABAergic signaling in regulating synaptic plasticity. The blockade of adenosine A<sub>1</sub> receptors increased the magnitude of long-term potentiation induced by specific burst patterns and differentially affected synaptic plasticity induced by 1-Hz LFS. Through its interactions with hippocampal rhythms and inhibitory circuits, adenosine elevated extracellularly during conditioning stimuli regulated the magnitude and direction of synaptic plasticity. This study proposes hypotheses for the role of adenosine in the modulation of synaptic plasticity, which maintains the balance between potentiation and depression in hippocampal circuits.</div></div>","PeriodicalId":19146,"journal":{"name":"Neuroscience Research","volume":"217 ","pages":"Article 104913"},"PeriodicalIF":2.4,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-01Epub Date: 2025-05-16DOI: 10.1016/j.neures.2025.05.002
Shimpei Ishiyama
Ticklishness is an idiosyncratic form of touch observed in multiple animal species, including humans. Although commonly regarded as trivial, it involves complex neurobiological mechanisms and diverse behavioral phenomena observed across species. Two distinct forms exist: knismesis, a mild tingling sensation elicited by gentle touch, and gargalesis, an intense sensation associated with involuntary laughter. Advocating the importance of clearly distinguishing these two types of ticklishness, this review synthesizes current knowledge on their neuronal underpinnings. Topics include somatosensory processing, self-tickling and sensory attenuation, emotional modulation, sociosexual dimensions, and evolutionary perspectives, among others. Special attention is given to the ambivalent nature of gargalesis, challenging conventional single-dimensional models of emotional valence. Ultimately, studying ticklishness provides a valuable opportunity to investigate playful emotional experiences from a naturalistic perspective, addressing fundamental yet underrepresented questions in contemporary neuroscience. Far from trivial, ticklishness thus provides valuable insights into the neural mechanisms underlying complex, context-dependent emotional and social experiences.
{"title":"The neurobiology of ticklishness","authors":"Shimpei Ishiyama","doi":"10.1016/j.neures.2025.05.002","DOIUrl":"10.1016/j.neures.2025.05.002","url":null,"abstract":"<div><div>Ticklishness is an idiosyncratic form of touch observed in multiple animal species, including humans. Although commonly regarded as trivial, it involves complex neurobiological mechanisms and diverse behavioral phenomena observed across species. Two distinct forms exist: knismesis, a mild tingling sensation elicited by gentle touch, and gargalesis, an intense sensation associated with involuntary laughter. Advocating the importance of clearly distinguishing these two types of ticklishness, this review synthesizes current knowledge on their neuronal underpinnings. Topics include somatosensory processing, self-tickling and sensory attenuation, emotional modulation, sociosexual dimensions, and evolutionary perspectives, among others. Special attention is given to the ambivalent nature of gargalesis, challenging conventional single-dimensional models of emotional valence. Ultimately, studying ticklishness provides a valuable opportunity to investigate playful emotional experiences from a naturalistic perspective, addressing fundamental yet underrepresented questions in contemporary neuroscience. Far from trivial, ticklishness thus provides valuable insights into the neural mechanisms underlying complex, context-dependent emotional and social experiences.</div></div>","PeriodicalId":19146,"journal":{"name":"Neuroscience Research","volume":"217 ","pages":"Article 104907"},"PeriodicalIF":2.4,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144094425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}