Central galanin administration blocks consolidation of spatial learning.
Galanin is a neuropeptide that inhibits the evoked release of several neurotransmitters, inhibits the activation of intracellular second messengers, and produces deficits in a variety of rodent learning and memory tasks. To evaluate the actions of galanin on encoding, consolidation, and storage/retrieval, galanin was acutely administered to Sprague-Dawley rats at time points before and after training trials in the Morris water maze. Intraventricular administration of galanin up to 3h after subjects had completed daily training trials in the Morris water task impaired performance on the probe trial, indicating that galanin-blocked consolidation. Pretreatment with an adenylate cyclase activator, forskolin, prevented the deficits in distal cue learning produced by galanin. Di-deoxyforskolin, an inactive analog of forskolin, had no effect. These results provide the first evidence that galanin interferes with long-term memory consolidation processes. A potential mechanism by which galanin produces this impairment may involve the inhibition of adenylate cyclase activity, leading to inhibition of downstream molecular events that are necessary for consolidation of long-term memory.
Kinney
Jefferson W
JW
Section on Behavioral Genomics, National Institute of Mental Health, Galanin Inhibits Consolidation, Building 10 Room 4011, Bethesda, MD 20892-1375, USA. jkinney@scripps.edu
Starosta
Grzegorz
G
Crawley
Jacqueline N
JN
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D005576:Colforsin / Q000494:pharmacology; D019004:Galanin / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012153:Retention, Psychology / Q000187:drug effects*; D013997:Time Factors; D014867:Water
D014867:Water; D005576:Colforsin; D019004:Galanin; D000262:Adenylyl Cyclases