From: (samson) Subject: Re: Help? Am I addicted to Cocaine? Date: 1996/11/13 newsgroups: alt.drugs,alt.drugs.hard [...] I think a lot of people are confused about just what the syndrome of cocaine addiction is and how it differs from opioid addiction. In animal studies, cocaine has been shown to most closely mimic direct electrical stimulation of the brain's "reward pathway" (a primarily dopaminergic system of neurons running through the "limbic system", the hypothalamus, and the midbrain). A rat will continuously and with increasing frequency over time press a lever which activates electrodes implanted in some part of this pathway (usually a limbic structure called the nucleus accumbens), preferring this behavior to eating, drinking, sleeping or any other sort of "reward", and to the point where the behavior actually results in death. If the lever activates an I.V. dose of cocaine or amphetamine, a nearly identical pattern is observed. The rat will increase its dose and frequency of dosing, cease eating, sleeping, etc., until it dies. On the other hand, if the animal is denied any more drug before it kills itself, it will continue to press the lever for a while, show some signs of "depression" (ie., slowed movement, sleeping, confusion), but after a relatively short period of time, it will return to normal rat-in-cage behavior. When the same procedure is done using morphine or heroin, the pattern is somewhat different. The preference for drug over food and the increase in self administration (dose and frequency) acquires significantly more slowly than with cocaine. Eventually a similar pattern is observed. However, there seems to be a "ceiling" effect, where dose frequency and amount increases to a point and then levels off. Ultimately, the animal will often resume much of its normal behavior (eat/sleep patterns, etc.), continuing a fairly stable drug dose- amount/frequency along with its "daily chores". (A morphine-dependent rat rarely ends up dead from overdose unless the experimenter plays a trick, like increasing the dose or moving the rat to an unfamiliar cage). But if the drug is suddenly discontinued, the animal shows signs of _severe_ physical distress (eg., squealing, rapid pacing, scratching, diarreah, insomnia, etc.) These results have been found by so many different researchers in so many different labs for so many years, that such "experiments" are basically just teaching tools, like frog dissections, at universities. There is also little controversy that the syndromes are similar in humans -- except, of course, that humans don't live in cages with levers they can press for their drugs. With heroin, especially, this adds a twist, because fluctuations in drug availability lead to periodic starting and stopping of the "experiment", with all the attendant complications. ================================================================= From: (samson) Subject: Re: Help? Am I addicted to Cocaine? Date: 1996/11/14 newsgroups: alt.drugs,alt.drugs.hard peter@petermc.demon.co.uk (Peter McDermott) wrote: > In article <56al7u$q98@sjx-ixn9.ix.netcom.com>, > pez@manhattan.com (Gizmo) wrote: > > > > >BIG HMMMMM. Are you so sure? Do you really think that humans don't > >live in cages? > > Oh, we live in cages OK, it's just that our cages don't have > levers in -- we have to go out and hunt for our drugs. Yes. And although I don't know if such experiments have been done or are feasible with the little fellers, I think it would be interesting to change the the parameters of the rat-with-a-lever experiments such that the rat _would_ have to hunt for its drugs. It would go something like this: Instead of one cage, there are several. Some have drug-providing levers, some do not (and some actually deliver different drugs or poisons). The rat has learned some way to get from cage to cage. Now, you start your rat out in cage 1, with the working cocaine- or morphine- delivering lever, let it develop a habit for a while, then cut it off. The rat is then allowed to "hunt" through the network of cages for more drug. (Its IV apparatus is portable -- I don't think rats are very good at "hitting" themselves). But now, throughout the network, there are all kinds of "obstacles" -- aversive stimuli, such as cages from which it cannot escape for a day, levers which deliver painful electrical shocks instead of drugs, etc. Given what is known from the single cage, unlimited drug experiments, what would one expect to see? Since cocaine quickly develops habituation in that hyperbolic upward curve to self-destruction, but entails only a moderately desperate situation upon withdrawal, we would expect our rat to do some hunting. But as long as it is unable to find more drug almost immediately, it will probably give up upon experiencing a moderate amount of aversive stimuli. (Unless, of course, there is more coke right there in cage 2...). "Morphine Mouse", provided he has been given enough time to at least approach the "stabilized" level of habituation observed with morphine, will be so sick upon withdrawal that he will probably endure much more pain to achieve his goal than the "crackrat". These "observations", taken together with the unlimited-drug-cage results, illustrate something of a paradox. The more "hunting" that is required, the less "addictive" cocaine seems relative to morphine, because the cocaine rat will suffer less to get more coke than the morphine rat will to get more M. (But remember, again, that the m-rat will habituate more slowly than the c-rat, and that the m-rat will stabilize its dose while the c-rat will not, in the unlimited-drug condition). But we don't need rats to see whether or not these hypotheses are borne out, because we can see what happens with humans (in general, of course). We can see that while human heroin addicts can be safely stabilized on methadone as a substitute, crack addicts cannot be stabilized on, say, methamphetamine. We can see that the "hunting environments" of heroin and crack addicts are very different. Where the heroin addict has all sorts of "aversive stimuli" to overcome (eg., jail, poverty, unscrupulous dealers, dirty needles), and will go through them like a hot knife through butter, crack addicts do not have quite the same plight, with the cheap and ready availability of crack and without the troubles associated with needles. (It is "right there in cage 2", as it were. And don't forget that a "sense of impending self-destruction" is an aversive stimulus for humans, but may not even exist in rats.) We also see a lot more human heroin addicts and ex-addicts with the brains and other resources still available to use the internet. If a.d.h is any guide, anyway... ================================================================= From: "R. Newcomb" Subject: Re: Help? Am I addicted to Cocaine? Date: 1996/11/15 newsgroups: alt.drugs,alt.drugs.hard [...] Regarding the rats on drugs research, it has also been found that if you carry out similar experiments with rats in more naturalistic conditions - eg. access to copulation, freedom to roam and forage etc. - then they are far less likely to hit the "more cocaine" lever to the point of destruction. There's a deep parallel with human behaviour here. Compare drug users living in poverty to those with jobs and lives. Get the picture?