The effect of 5-HT3 receptor agonist of the ventral hippocampus on amnesia induced by ethanol in mice

Background: The aim of this study was to investigate the effect of 5-HT3 receptor agonist in the CA1 hippocampus area on demolition of ethanol-induced memory. Materials and Methods: This study was conducted on 96 NMRI mice. Ethanol was injected intraperitoneally, while 5-HT3 receptor agonist (MCHL) was injected intra-CA1. To assess the memory, a single-trial step-down passive avoidance apparatus was used. Results: Results showed that pre-training injection of ethanol (1mg/kg), and MCHL (0.5 ng/mouse) decreased a passive avoidance memory in the adult mice. Also, a non- effective dose of MCHL (0.005 ng/mouse) with a non- effective dose of ethanol (0.01mg/kg) induced amnesia. Also, the results showed that injection of different doses of MCHL (0.5, 0.05, and 0.005 ng/mouse) combined with an effective dose of ethanol (1mg/kg) could retrieve damaged memory by ethanol. Conclusion: Findings of this study showed that the CA1 region of the hippocampus has an important role in amnesia induced by serotonin and serotonin CA1 5-HT3 receptor agonists have interaction with ethanol

The effect of 5-HT3 receptor agonist of the ventral hippocampus on amnesia induced by ethanol in mice

Background: The aim of this study was to investigate the effect of 5-HT3 receptor agonist in the CA1 hippocampus area on demolition of ethanol-induced memory. Materials and Methods: This study was conducted on 96 NMRI mice. Ethanol was injected intraperitoneally, while 5-HT3 receptor agonist (MCHL) was injected intra-CA1. To assess the memory, a single-trial step-down passive avoidance apparatus was used. Results: Results showed that pre-training injection of ethanol (1mg/kg), and MCHL (0.5 ng/mouse) decreased a passive avoidance memory in the adult mice. Also, a non- effective dose of MCHL (0.005 ng/mouse) with a non- effective dose of ethanol (0.01mg/kg) induced amnesia. Also, the results showed that injection of different doses of MCHL (0.5, 0.05, and 0.005 ng/mouse) combined with an effective dose of ethanol (1mg/kg) could retrieve damaged memory by ethanol. Conclusion: Findings of this study showed that the CA1 region of the hippocampus has an important role in amnesia induced by serotonin and serotonin CA1 5-HT3 receptor agonists have interaction with ethanol

The Role of 5HT3 Receptor Antagonist of the Lateral Hippocampus on Amnesia Induce by Morphine in Mice

Background and Objectives: Learning and memory processes occur as a result of interaction of neurotransmitter systems in various brain regions, such as hippocampus. The evidences indicated that serotonergic and opioidergic systems involve in behavioral, learning, and memory results. In the present study, we investigated the effect of the serotonergic system (5-HT) of the lateral hippocampus (CA1) on morphine-induced amnesia.   Methods: In this experimental study, the animals were bilaterally implanted with cannulas in the CA1 region of the lateral hippocampus. Morphine was injected intraperitoneally and 5-HT3 receptor antagonist (Y-25130) was injected into the CA1 region. The memory was assessed by a single-trial step-down passive avoidance task and tested after training. The step-down latency was used for the assessment of memory retention in adult male NMRI mice. One-way analysis of variance, followed by Tukey test, were used for the analysis of data.   Results: In this study, pre-test injection of morphine (dose, 5mg/kg) and Y-25130 (dose, 1ng/mouse) decreased memory acquisition process in the adult mice. In addition, ineffective dose of Y-25130 (0.01ng/mouse) along with ineffective dose of morphine (5mg/kg) induced amnesia in mice.   Conclusion: The results of this study showed that there is a synergistic effect between 5-HT3 receptor antagonists of hippocampal CA1 region and morphine.   : &nbsp

Evaluation of the Interaction between NMDA Receptors of Nucleus Accumbens and Muscarinic Receptors in Memory

Background and Objectives: Whereas studies have indicated the interaction between NMDA and cholinergic systems, this study was performed with the aim of determining the role of NMDA receptors in the nucleus accumbens (NAc) in scopolamine-induced amnesia.Methods: In this study, at first rats were anesthetized with intra-peritoneal injection of ketamine hydrochloride plus xylazine, and then placed in a stereotaxic apparatus. Two stainless-steel cannulas were placed 2mm above nucleus accumbens shell. All animals were allowed to recover for one week, before beginning the behavioral testing. Then, animals were trained in a step-through type inhibitory avoidance task. The drugs were injected after successful training and before testing. The animals were tested 24h after training, and the step-through latency time was measured as the memory criterion in male Wistar rats. One-way analysis of variance and Tukey’s test were used for analysis of the data. p<0.05 was considered statistically significant.Results: Intra-nucleus accumbens (intra-NAc) injection of scopolamine or NMDA caused impairment in memory in rats. Although, co-administration of an ineffective dose of NMDA with an ineffective dose of scopolamine had no significant effect on memory performance, effective doses of NMDA prevented the amnesic effect of scopolamine on inhibitory avoidance memory. On the other hand, intra-NAc injection of NMDA receptor antagonist, i.e., MK-801 caused no change in memory performance by itself, and its co-administration with an effective dose of scopolamine could not prevent the impairing effect of the latter drug. Conclusion: The finding of this study indicated that NMDA receptors in the nucleus accumbens are involved in the modulation of scopolamine-induced amnesia