Effects of intrahippocampal injection of ghrelin on spatial memory in PTZ-induced seizures in male rats

Ghrelin (gh) is a peptide hormone that may affect learning and memory. There is some evidence that ghrelin can have antiepileptic effects. So we decided to investigate the possible effects of ghrelin on spatial memory following PTZ-induced seizures in male rats. Ninety male rats were divided into 9 groups including control, saline, ghrelin (0.3, 1.5 or 3 nmol) and pentylenetetrazol (PTZ, 50 mg/kg, i.p.) plus saline or ghrelin (0.3, 1.5 or 3 nmol). All groups were trained in Morris water maze (MWM) for two consecutive days. Our results showed that ghrelin significantly improves spatial memory at the doses of 1.5 or 3 nmol (P < 0.05) in normal rats. We also demonstrated the significant impairment of spatial memory in PTZ group (P < 0.05). Intrahippocampal injection of ghrelin at the dose of 3 nmol significantly improved spatial memory in PTZ + gh group compared to PTZ group (P < 0.05). These findings suggest that ghrelin as a neuropeptide can improve spatial memory in PTZ-treated rats.