Response to novel environment following septal lesions or cholinergic blockage in rats

Compared rates of habituation of an exploratory head-poke response for 48 control, 16 septally lesioned, and 16 scopolamine-hydrobromide-injected male albino holtzman rats. Controls exhibited decreasing response rates and increasing durations/response within sessions. Response-contingent light presentation attenuated both effects and had an activating rather than a direct reinforcing effect. Both the scopolamine-hydrobromide-injected ss and ss with septal lesions showed decreasing response rates similar to controls; however, neither increased their durations/response, suggesting a more profound impairment of habituation. Both reacted to response-contingent light presentation similarly to controls but in a more exaggerated fashion indicating that an increased responsivity to response-produced stimulus feedback caused the habituation deficit. (PsycINFO Database Record (c) 2006 APA, all rights reserved).