ISSN:
1432-2072
Keywords:
Glutamate
;
Kainate
;
Ketamine
;
Kynurenic acid
;
MK-801
;
NMDA
;
Phencyclidine
;
Rat
;
Self-stimulation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract MK-801 is a ligand at phencyclidine recognition sites associated with NMDA-coupled cation channels, where it acts as a potent noncompetitive antagonist of central glutamate/aspartate (NMDA-type) receptors. Low doses (10–100 μg/kg IP) produced a dose-related and prolonged (〉1 h) enhancement of variable-interval self-stimulation responding. Higher doses (300 μg/kg) caused flaccid ataxia and disrupted responding. Ketamine HCl (3.0–100 mg/kg IP), a dissociative anaesthetic binding to the phencyclidine site, produced a similar response pattern, but facilitation was less prolonged and occurred over a narrower dose range. Kynurenic acid (3.0–300 mg/kg IP), a nonselective competitive antagonist of glutamate receptors, produced only depression of responding, possibly the result of kynurenate-induced blockade of central kainate and/or quisqualate receptors. The behavioural stimulant effects of MK-801 appear to be an intrinsic and essential feature of selective NMDA antagonists, and these effects of MK-801 differ qualitatively and quantitatively from the well-known facilitatory effects of dopamine-dependent stimulants.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00634458
