The locomotor effects of MK801 in the nucleus accumbens of developing and adult rats.
This developmental study was an investigation of locomotion induced by the NMDA receptor antagonist, (+)MK-801 hydrogen maleate [(5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5, 10-imine], at doses of 0, 3 or 10 microg injected bilaterally into the nucleus accumbens of rats at 11, 21, 31, or 61-66 days of age. During a 2-h test session, only a few 11-day-old pups responded to either dose of MK801; they displayed short bouts of obstinate progression. In contrast, 21- and 31-day-olds were not affected by 3 microg MK801 but exhibited robust activation after 10 microg MK801. The activation was greatest in 21-day-olds and also occurred after mid-striatal injections in 21- but not 31-day-old rats. Adult rats injected with MK801 were not robustly activated, but they maintained their initial level of activity throughout the test session, instead of habituating to the test monitor, as controls did. Ontological changes in MK801-induced activity are likely to reflect maturation of glutamate transmission in the nucleus accumbens.
Frantz
K
K
Department of Psychology, University of Florida, Gainesville 32611-2250, USA. kfrantz@sage.scripps.edu
Van Hartesveldt
C
C
D000818:Animals; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D005260:Female; D007276:Injections, Intraventricular; D008124:Locomotion / Q000187:drug effects; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009714:Nucleus Accumbens / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D013997:Time Factors
D018691:Excitatory Amino Acid Antagonists; D016291:Dizocilpine Maleate