Eeg patterns during the behavioural desensitization to scopolamine in rats

Rats pretrained in ago-nogo avoidance discrimination were treated daily with 1mgkg of scopolamine HBr s.c. 40 min before testing sessions. EEG records were taken twice a week, before and after sessions. The drug caused initially a disruption in performance and EEG synchronization. Upon repeated exposure the behavioural deficit was progressively compensated for, while the EEG alteration persisted. The administration of physostigmine (1mgkg s.c.) to desensitized scopolamine-treated animals provoked a disruption in the performance and an EEG desynchronization. Repeated exposure to scopolamine and physostigmine led to a rapid behavioural desensitization to the combined treatment.