AR-News: Breakthrough: Monkeys should think twice about long-term use of cocaine

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From: primfocus at waste.org

J Neurosci. 2004 Apr 7;24(14):3554-62.


Cocaine self-administration produces a progressive involvement of limbic,
association, and sensorimotor striatal domains.

Porrino LJ, Lyons D, Smith HR, Daunais JB, Nader MA.

Center for the Neurobiological Investigation of Drug Abuse, Department of
Physiology and Pharmacology, Wake Forest University School of Medicine,
Winston-Salem, North Carolina 27157.

The primate striatum is composed of limbic, cognitive, and sensorimotor
functional domains. Although the effects of cocaine have generally been
associated with the ventral striatum, or limbic domain, recent evidence in
rodents suggests the involvement of the dorsal striatum (cognitive and
sensorimotor domains) in cocaine self-administration. The goals of the
present studies were to map the topography of the functional response to
cocaine throughout the entire extent of the striatum of monkeys
self-administering cocaine and determine whether this response is modified
by chronic exposure to cocaine. Rhesus monkeys were trained to
self-administer 0.3 mg/kg per injection cocaine for 5 d (initial stages; n =
4) or 100 d (chronic stages; n = 4) and compared with monkeys trained to
respond under an identical schedule of food reinforcement (n = 6). Monkeys
received 30 reinforcers per session, and metabolic mapping was conducted at
the end of the 5th or 100th self-administration session. In the initial
phases of cocaine exposure, self-administration significantly decreased
functional activity in the ventral striatum, but only in very restricted
portions of the dorsal striatum. With chronic cocaine self-administration,
however, the effects of cocaine intensified and spread dorsally to include
most aspects of both caudate and putamen. Early experiences with cocaine,
then, involve mainly the limbic domain, an area that mediates motivational
and affective functions. In contrast, as exposure to cocaine continues, the
impact of cocaine impinges progressively on the processing of sensorimotor
and cognitive information, as well as the affective and motivational
information processed in the ventral striatum.



the wild, cruel beast is not behind the bars of the cage. he is in front of it - axel munthe

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Indeed, it's the only thing that ever has."      Margaret Mead
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