ISSN:
1432-2072
Keywords:
Rotational behavior
;
Amphetamine
;
Apomorphine
;
Sensitization
;
Sex differences
;
Gonadal hormones
;
Reverse tolerance
;
6-Hydroxydopamine
;
Amphetamine psychosis
;
Conditioning
;
Dopamine
;
Rat
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Factors influencing the behavioral sensitization (“reverse tolerance”) produced by intermittent amphetamine (AMPH) injections were studied by quantifying rotational behavior in rats that had a unilateral 6-hydroxydopamine lesion of the substantia nigra. The results indicate that (1) a single injection of a low dose of AMPH enhances rotational behavior induced by a second injection of AMPH for up to 12 weeks; (2) multiple, weekly injections of AMPH produce a progressive enhancement in rotational behavior, over-and-above that produced by a single injection; (3) female rats show more robust sensitization than males following single or multiple injections of AMPH; (4) this sex difference may be due to the suppression of sensitization by an androgen, because removal of testicular hormones potentiates sensitization; (5) the long-lasting sensitization of rotational behavior produced by infrequent injections of AMPH is not due to drug-environment conditioning effects, but perhaps to a persistent AMPH-induced change(s) in brain catecholamine systems; and (6) a simple change in DA receptors is probably no involved, because the sensitization produced by infrequent injections of AMPH does not influence the rotation produced by a subsequent injection of apomorphine. The results illustrate an intriguing example of neuroplasticity that may have clinical relevance.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00431451
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