Vasopressin and memory. I. The vasopressin analogue AVP4-9 enhances working memory as well as reference memory in the radial arm maze.
The present study examined the effects of vasopressin on memory. Healthy rats were injected with the arginine vasopressin fragment AVP4-9 and the AVP antagonist [beta-mercapto-beta,beta-cyclopentamethylenepropionyl1,O-Et-Pyr 2,Val4,Arg8] and were tested in an eight-arm radial maze for 60 sessions. All injections were given s.c. 30 min prior to testing. AVP4-9 enhanced radial arm maze performance. AVP4-9 treated animals showed enhancement in performance as well as increases in the rate of learning, indicating that they learned the task faster. Furthermore, the overall memory enhancement was due to improved working memory as well as to improved reference memory. These results cannot be explained in terms of changes in locomotor activity because an open field test revealed no differences between groups for both of these compounds. The AVP antagonist did not impair performance in the radial maze. It is concluded that AVP4-9 has a more general effect on memory, one that is not limited to a specific type of memory.
Dietrich
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A
Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA. adietri@emory.edu
Allen
J D
JD
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D001931:Brain Mapping; D006624:Hippocampus / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D011939:Mental Recall / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D012153:Retention, Psychology / Q000187:drug effects*
D010446:Peptide Fragments; D001127:Arginine Vasopressin; C045881:argipressin (4-9)