The effects of hippocampal and fimbria-fornix lesions on prepulse inhibition.
The present experiments tested the effects of conventional (dorsal aspiration and electrolytic) and excitotoxic (N-methyl-D-aspartate [NMDA]) hippocampal lesions and fimbria-fornix (FF) transection on prepulse inhibition (PPI) of startle response and on open-field activity. Activity was increased by FF transection and by conventional but not excitotoxic hippocampal lesions; complete NMDA lesion increased amphetamine-induced activity. Whereas dorsal hippocampal aspiration lesion disrupted PPI, the phenomenon was not affected by dorsal hippocampal electrolytic lesion, partial or complete excitotoxic (NMDA) hippocampal lesions, or complete FF transection, which interrupted the cholinergic input to the hippocampus as well as the hippocampal-subicular input to the nucleus accumbens. Systemic apomorphine disrupted PPI in both FF-transected rats and their controls. It is suggested that the hippocampus is essential for PPI disruption rather than for PPI expression.
Pouzet
B
B
Behavioural Biology Laboratory, Swiss Federal Institute of Technology Zurich, Schwerzenbach.
Feldon
J
J
Veenman
C L
CL
Yee
B K
BK
Richmond
M
M
Nicholas
J
J
Rawlins
P
P
Weiner
I
I
D000161:Acoustic Stimulation; D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D004558:Electric Stimulation; D018690:Excitatory Amino Acid Agonists; D020712:Fornix, Brain / Q000187:drug effects / Q000293:injuries / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects / Q000293:injuries / Q000502:physiology*; D007266:Inhibition, Psychological; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D016202:N-Methylaspartate; D051381:Rats; D017208:Rats, Wistar; D013216:Reflex, Startle / Q000187:drug effects / Q000502:physiology*; D013396:Suction
D018491:Dopamine Agonists; D018765:Dopamine Uptake Inhibitors; D018690:Excitatory Amino Acid Agonists; D016202:N-Methylaspartate; D000661:Amphetamine; D001058:Apomorphine