D-amphetamine facilitation of morris water task performance is blocked by eticlopride and correlated with increased dopamine synthesis in the prefrontal cortex.
The effect of posttraining D-amphetamine on Morris water task (MWT) performance was analyzed in this study by training rats using a single training trial per day procedure. In addition to acquisition latency, learning was assessed by a probe trial given 24 h after the last training trial. Rats given immediate post-trial D-amphetamine demonstrated improved performance over saline rats on both acquisition and the probe trial. An analysis of the mechanisms underlying facilitation revealed that eticlopride (a D2 antagonist) blocked D-amphetamine's facilitatory effects on the probe trial and dopamine synthesis was increased in the medial prefrontal cortex in the D-amphetamine group relative to controls. These results show that chronic administration of posttraining D-amphetamine facilitated MWT performance, and this facilitation may be mediated by the dopaminergic system and dopamine synthesis in the prefrontal cortex.
Brown
R W
RW
Department of Psychology and Neuroscience, University of Lethbridge, 4401 University Drive, T1K 3M4, Lethbridge, AB, Canada. russell.brown@uleth.ca
Bardo
M T
MT
Mace
D D
DD
Phillips
S B
SB
Kraemer
P J
PJ
D000818:Animals; D000697:Central Nervous System Stimulants / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D003913:Dextroamphetamine / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D004295:Dihydroxyphenylalanine / Q000378:metabolism; D004298:Dopamine / Q000096:biosynthesis* / Q000378:metabolism; D018492:Dopamine Antagonists / Q000494:pharmacology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012457:Salicylamides / Q000494:pharmacology*
D000697:Central Nervous System Stimulants; D018492:Dopamine Antagonists; D012457:Salicylamides; D004295:Dihydroxyphenylalanine; C045989:eticlopride; D003913:Dextroamphetamine; D004298:Dopamine