Dynorphin A-(1-13) potently improves galanin-induced impairment of memory processes in mice.
The present study examined the effects of intracerebroventricular injection of dynorphin A-(1-13) on memory processes by using the passive avoidance task in mice. Galanin (0.3 microgram) significantly shortened the step-down latency when given 15 min before retention tests. Although dynorphin A-(1-13) (1 or 3 micrograms) did not prolong the step-down latency induced by weaker electroshocks, it inhibited the galanin (0.3 micrograms)-induced shortening of step-down latency. The effects of dynorphin A-(1-13) (3 micrograms) on the galanin-induced shortening of step-down latency were almost completely reversed by pretreatment with nor-binaltorphimine (4 micrograms), a kappa-selective opioid antagonist. These results strongly suggest that dynorphin A-(1-13) attenuates galanin-induced impairment of memory processes through the mediation of kappa-opioid receptors.
Kameyama
T
T
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Meijo University, Nagoya, Japan.
Ukai
M
M
Miura
M
M
D000647:Amnesia / Q000139:chemically induced; D000818:Animals; D004399:Dynorphins / Q000494:pharmacology*; D019004:Galanin; D008297:Male; D008568:Memory / Q000187:drug effects*; D051379:Mice; D010446:Peptide Fragments / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology*; D017473:Receptors, Opioid, kappa / Q000187:drug effects
D010446:Peptide Fragments; D010455:Peptides; D017473:Receptors, Opioid, kappa; C026843:dynorphin (1-13); D004399:Dynorphins; D019004:Galanin