{"title":"Effects of oxotremorine on convulsions in mice induced by scopolamine and food intake after fasting.","authors":"Berna Midilli, Asiye Nurten, Başak Gürtekin, Nurhan Enginar","doi":"10.1016/j.bbr.2024.115402","DOIUrl":null,"url":null,"abstract":"<p><p>Antimuscarinic administration and food intake cause convulsions in mice and rats after fasting for 48h or less. Increased M<sub>1</sub> and M<sub>2</sub> muscarinic receptor expression in brain regions during fasting, and reversal of changes by refeeding may contribute to these seizures. Since receptor expression is regulated in response to agonist stimulation, this study investigated effects of nonselective muscarinic receptor agonist oxotremorine on convulsions in fasted animals. Mice deprived of food for 24h were given oxotremorine during (0.1mg/kg, twice daily, s.c.) or after (0.05 or 0.1mg/kg, i.p.) fasting. Fasted animals were treated with saline or scopolamine (i.p.) and observed for 30min for the convulsions after being allowed to eat ad libitum. Oxotremorine administration during fasting produced no significant effect on convulsion development. Incidence and onset of convulsions, and seizure stages were indifferent between the scopolamine and oxotremorine - scopolamine groups. However, oxotremorine (0.1mg/kg) administration after fasting reduced incidence of convulsions. Resulting from an agonist-antagonist interaction at M<sub>1</sub> and/or M<sub>2</sub> muscarinic receptors, oxotremorine administered after fasting exhibited an anticonvulsant activity. Oxotremorine administration during fasting was expected to suppress seizure development via inhibition of receptor expression. Results did not confirm this expectation and suggested that muscarinic receptor expression was either not affected or not related to the convulsions. Food intake after fasting, and food deprivation have been shown to induce cholinergic hyperexcitability. Although contrary to our hypothesis, future research may investigate whether increased expression of muscarinic receptors mediate or contribute to an increase in cholinergic activity.</p>","PeriodicalId":8823,"journal":{"name":"Behavioural Brain Research","volume":" ","pages":"115402"},"PeriodicalIF":2.6000,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Behavioural Brain Research","FirstCategoryId":"102","ListUrlMain":"https://doi.org/10.1016/j.bbr.2024.115402","RegionNum":3,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BEHAVIORAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Antimuscarinic administration and food intake cause convulsions in mice and rats after fasting for 48h or less. Increased M1 and M2 muscarinic receptor expression in brain regions during fasting, and reversal of changes by refeeding may contribute to these seizures. Since receptor expression is regulated in response to agonist stimulation, this study investigated effects of nonselective muscarinic receptor agonist oxotremorine on convulsions in fasted animals. Mice deprived of food for 24h were given oxotremorine during (0.1mg/kg, twice daily, s.c.) or after (0.05 or 0.1mg/kg, i.p.) fasting. Fasted animals were treated with saline or scopolamine (i.p.) and observed for 30min for the convulsions after being allowed to eat ad libitum. Oxotremorine administration during fasting produced no significant effect on convulsion development. Incidence and onset of convulsions, and seizure stages were indifferent between the scopolamine and oxotremorine - scopolamine groups. However, oxotremorine (0.1mg/kg) administration after fasting reduced incidence of convulsions. Resulting from an agonist-antagonist interaction at M1 and/or M2 muscarinic receptors, oxotremorine administered after fasting exhibited an anticonvulsant activity. Oxotremorine administration during fasting was expected to suppress seizure development via inhibition of receptor expression. Results did not confirm this expectation and suggested that muscarinic receptor expression was either not affected or not related to the convulsions. Food intake after fasting, and food deprivation have been shown to induce cholinergic hyperexcitability. Although contrary to our hypothesis, future research may investigate whether increased expression of muscarinic receptors mediate or contribute to an increase in cholinergic activity.
期刊介绍:
Behavioural Brain Research is an international, interdisciplinary journal dedicated to the publication of articles in the field of behavioural neuroscience, broadly defined. Contributions from the entire range of disciplines that comprise the neurosciences, behavioural sciences or cognitive sciences are appropriate, as long as the goal is to delineate the neural mechanisms underlying behaviour. Thus, studies may range from neurophysiological, neuroanatomical, neurochemical or neuropharmacological analysis of brain-behaviour relations, including the use of molecular genetic or behavioural genetic approaches, to studies that involve the use of brain imaging techniques, to neuroethological studies. Reports of original research, of major methodological advances, or of novel conceptual approaches are all encouraged. The journal will also consider critical reviews on selected topics.