From: [d--p--n] at [ziggys.cts.com] (Rex Kahler)  619/262-6384
Newsgroups: alt.drugs
Subject: Amphetamine, cocaine: New link
Date: Tue, 07 Dec 93 01:03:19 PST

(from an issue of Bottom Line Magazine..not sure of date or #):
(reprinted wholly without permission)

"A brain structure largely ignored by drug addiction researchers
may play an important role in producing the similar ill effects
of amphetamine and cocaine binges, including hallucinations and 
gradually worsening paranoia, according to a report accepted for 
publication in BRAIN RESEARCH. If the findings hold up, they may
lead to a new theory of how disturbances involving the chemical
messenger dopamine promote various types of psychosis, asserts
psychologist Gaylord Ellison of the University of California, Los
Angeles.

Prior animal research has found that taking amphetamine for several
days damages dopamine-rich cells in a brain area called the caudate,
while comparable cocaine intake leaves the caudate unscathed. However,
these studies often rely on daily drug injections that fall far short
of the "speed runs" of human addicts, who may consume cocaine or am-
phetamine every few hours for days, Ellison notes.

He and his co-workers developed slow-release silicone pellets that,
when implanted under the skin, deliver continuous doses of either
amphetamine or cocaine for five days.

Rats implanted with amphetamine pellets, but not those bearing cocaine
pellets, display caudate damage by the third day, based on staining and
microscopic analysis of their brains. However, both groups suffer ex-
tensive damage to a structure near the center of the brain, the habenula,
and its cell connections to a related region, Ellison contends.
Anatomical studies indicate that the habenula helps to regulate dopamine 
transmission by slowing its release elsewhere. The habenula also
maintains connections to cells that produce serotonin, a chemical
courier involved in hallucinations, Ellison holds. Destruction of cell 
pathways linking the habenula to other brain structures may at least
partly cause amphetamine and cocaine psychosis, he proposes."



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