Scopolamine administered before and after training impairs both contextual and auditory-cue fear conditioning.
When administered before training to 23-day-old Long-Evans rats, scopolamine hydrobromide significantly impaired both contextual and auditory-cue fear conditioning in a dose-dependent manner. Methylscopolamine which does not cross the blood-brain barrier, however, had no effect on either form of conditioned fear. Scopolamine administered up to 3 h after training also impaired both forms of fear conditioning when administered following a single pairing of the auditory cue and shock. When rats received three pairings, however, a posttraining treatment with scopolamine only impaired contextual fear conditioning. These results suggest that central cholinergic systems are involved in the posttrial processes that establish the memory trace for the conditioning experience.
Rudy
J W
JW
Department of Psychology, University of Colorado, Boulder 80309-0345, USA jrudy/clipr.colorado.edu.
D000818:Animals; D001307:Auditory Perception / Q000187:drug effects*; D001522:Behavior, Animal / Q000187:drug effects; D003213:Conditioning, Psychological / Q000187:drug effects*; D005239:Fear / Q000187:drug effects*; D005260:Female; D008297:Male; D010276:Parasympatholytics / Q000009:adverse effects* / Q000494:pharmacology*; D051381:Rats; D012601:Scopolamine / Q000009:adverse effects* / Q000494:pharmacology*
D010276:Parasympatholytics; D012601:Scopolamine