Oral Communications

AIM: Absence epilepsy and psychiatric disorders have a bidirectional relationship and also different severity at various ages.Also, recent studies have shown that Trpv1 channel expression is altered in the diseases mentioned.The present study aims to investigate whether rivastigmine (RIVA), an acetylcholinesterase inhibitor, affects age-related changes in spike-wave discharges (SWDs), learning-memory problems, anxiety, and changes in Trpv1 gene expression levels in WAG/Rij rats.METHODS: In the study (OMU-HADYEK 2024/19), 5-and 13-monthold WAG/Rij (n=70) and only 5-month-old Wistar (n=14) male rats were used.Initially, electrophysiologic recordings were obtained from WAG/Rij rats after a single dose of 0.125 and 2 mg/kg injection and 24 hours after the end of the 14-day (long-term) administration of only 2 mg/kg dose to determine the effect of RIVA on SWDs.In the next step, both WAG/Rij and Wistar rats were subjected to y-maze and elevated-plus testing 24 hours after longterm administration.Following the behavioral tests, right-cortex and right-hippocampus of the rats were removed to used in the qPCR.Statistically, according to the results of Shapiro-Wilk test, ttest or one-way ANOVA test was applied.RESULTS: RIVA showed similar effects in all WAG/Rij rats.0.125 mg/kg was insignificant, whereas 2 mg/kg almost completely abolished SWDs (p<0.001) and reduced mean durations of SWDs (p<0.05).In the long-term; increased the number of SWDs and decreased the mean duration of SWDs (p<0.001),decreased shortterm memory performance(p<0.05),and decreased anxiety (p<0.05).The Trpv1 gene levels; decreased in all WAG/Rij rat groups and increased in Wistar rats (p<0.001).CONCLUSIONS: RIVA shows similar effects in all age groups: antiepileptic at acute doses and pro-epileptic in long-term.RIVA negatively affected learning-memory while decreasing anxiety in WAG/Rij rats.Regarding Trpv1 gene expressions, WAG/Rij and Wistar rats showed opposing effects.We speculate that the effect of RIVA on absence seizures and accompanying memory impairment with anxiety may be Trpv1-channel related.