Neurological Correlates - The Neuroscience of Dysfunctional Behavior

Things go better with meth, as compared to cocaine, if you’re dopamine transporter challenged, anyway.

November 19, 2008
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The Pepsi challenge with controlled substances: Meth vs. Coke.

Methamphetamine is taken up more quickly, and last longer than cocaine.  (Fowler et al, Abstract below).

And here’s something from Microgram Bulletin, October 2008, Published by the Drug Enforcement Administration  Office of Forensic Sciences Washington, D.C. 20537:

The DEA South Central Laboratory (Dallas, Texas) recently received a submission of approximately 4972 fake “kidney beans” (total net mass 3,210 grams), all containing a fine tan powder, suspected heroin (see Photo 10). The “beans” were actually small plastic packets that had been painted to resemble kidney beans (see Photo 11). A few genuine beans (of a much lighter color) were mixed in with the fakes (see the light brown beans in Photo 11, previous page). The exhibits were seized by DEA Special Agents in El Paso, Texas (no further details). Analysis of the powder by FTIR-ATR, GC/MS, and GC/FID confirmed 90.3% heroin hydrochloride. This was the first such submission to the South Central Laboratory. . . .

The perhaps undeniable point: probably the self-selecting population of people who are first drawn to drugs, and then become irretrievably addicted, are those who lack sufficient dopamine transport to feel fulfilled (or other insufficency, depending on the choice of drug). They are, in essence, self-medicating, rather than using drugs for recreational use. I mean, you don’t load up kidney beans for recreational drug users.

I’m reminded of a friends’ younger brother, from a locally well known family, whose arrest was reported as bringing in “the largest amount” of cocaine in those parts.  His remark: He was a wholesaler, and the newpaper quoted street (“retail”) values, so the report inflated his inventory value.  This was purely about money for him — he made far more money selling coke than any job he was qualified to do (which was, well, probably none, unless being a bon vivant and sparkling racounteur with insufficient money to fund a high rent party lifestyle qualifies as a profession, which it may). If the US were to decriminalize drug use, and fund a program to make an agonist which was not addictive (a la the whole methadone thing), probably we could solve much of the crime problem in the Western Hemisphere.

Neuroimage. 2008 Dec;43(4):756-63. Epub 2008 Jul 22.

Fast uptake and long-lasting binding of methamphetamine in the human brain: comparison with cocaine.

Fowler JS, Volkow ND, Logan J, Alexoff D, Telang F, Wang GJ, Wong C, Ma Y, Kriplani A, Pradhan K, Schlyer D, Jayne M, Hubbard B, Carter P, Warner D, King P, Shea C, Xu Y, Muench L, Apelskog K.

Medical Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
fowler@bnl.gov

Methamphetamine is one of the most addictive and neurotoxic drugs of abuse. It produces large elevations in extracellular dopamine in the striatum through vesicular release and inhibition of the dopamine transporter. In the U.S. abuse prevalence varies by ethnicity with very low abuse among African Americans relative to Caucasians, differentiating it from cocaine where abuse rates are
similar for the two groups. Here we report the first comparison of methamphetamine and cocaine pharmacokinetics in brain between Caucasians and African Americans along with  the measurement of dopamine transporter availability in striatum. Methamphetamine’s uptake in brain was fast (peak uptake at 9 min) with accumulation in cortical and subcortical brain regions and in white matter. Its clearance from brain was slow (except for white matter which did not clear over the 90 min) and there was no difference in pharmacokinetics between Caucasians and African Americans. In contrast cocaine’s brain uptake and clearance were both fast, distribution was predominantly in striatum and uptake
was higher in African Americans.

Among individuals, those with the highest striatal (but not cerebellar) methamphetamine accumulation also had the highest dopamine transporter availability suggesting a relationship between METH exposure and DAT availability. Methamphetamine’s fast brain uptake is consistent with its highly reinforcing effects, its slow clearance with its long-lasting behavioral
effects and its widespread distribution with its neurotoxic effects that affect not only striatal but also cortical and white matter regions. The absence of significant differences between Caucasians and African Americans suggests that variables other than methamphetamine pharmacokinetics and bioavailability account for the lower abuse prevalence in African Americans.

PMID: 18708148 [PubMed - in process]
Related Links

PET studies of d-methamphetamine pharmacokinetics in primates: comparison with
l-methamphetamine and ( –)-cocaine. [J Nucl Med. 2007] PMID:17873134

Long-term methamphetamine administration in the vervet monkey models aspects of a
human exposure: brain neurotoxicity and behavioral profiles.
[Neuropsychopharmacology. 2008] PMID:17625500

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4 Responses to Things go better with meth, as compared to cocaine, if you’re dopamine transporter challenged, anyway.

  1. Neuroskeptic on November 19, 2008 at 3:26 pm

    A non-addictive dopamine agonist – would be a great thing, although according to many theories of addiction, that’s pretty much impossible, because dopaminergic action is what makes stuff addictive…

  2. swivelchair on November 19, 2008 at 5:17 pm

    Hi NS, thanks for the comment. Hmm. Makes sense, more research is needed in any event. And, I’ll put up a link, so you can count me as your regular reader ;)

  3. FAROUCHE OMBRÉ on December 26, 2008 at 5:30 pm

    Phytohaemagglutinin Poisoning can be induced from as few as five raw beans and symptoms occur within three hours, It is found in the highest concentrations in uncooked red kidney beans and white kidney beans (also known as cannellini). As a toxin it can cause poisoning in monogastric animals, such as humans, through the consumption of raw or improperly prepared kidney beans. From Wikipedia. Correlated with the time line status.

  4. slacker on April 29, 2011 at 5:42 am

    Interesting article , I’m going to spend more time learning about this subject

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