[Effects of intramedial septum infusion of physostigmine on hippocamal EEG and spatial memory in animal model of Alzheimer's disease]

The basalis magnocellularis nucleus [NBM] cholinergic projections to amygdala and forntal cortex have a crucial role in spatial learning and memory. There are relations between septum, hippocampus, amygdala and cerebral cortex. The role of NBM cholinergic projections to medial septum and then to hippocampus on spatial learning and memory, hippocamal EEG in animal model of Alzheimer's disease was assessed after unilateral lesion of NBM with phtalic acid [300 ng/kg]. Physostigmine was infused into the medial septum. Forty wistar male rats were divided in 4 groups: control, lesioned, lesioned received saline and lesioned treated with physostigmine [5microg/microl]. Animals were operated stereotaxicaly for NBM lesioning, intramedial septum cannulation and hippocamal electrode implantation. Rats were trained one session daily into T-maze and alterations of hippocampal EEG amplitude were evaluated. The results showed intramedial septum infusion of physostigmine improves spatial learning and memory in lesioned animals significantly [p<0.01]. NBM cholinergic projections to medial septum and then the hippocampus as well as its projections to amygdala and cortex have a role in spatial learning and memory. Administration of physostigmine improves decrease of hippocampal EEG amplitiude, spatial learning and memory impairment that was induced by NMB lesioning in male rats