by oscilor on Thu Dec 17, 2009 5:39 am
Was musing on this thread last night in bed...here are my thoughts...haloperidol’s mechanism of action is to block dopamine receptors in the nucleus accumbens (NA).
Nucleus accumbens is a reward centre in the brain....rats with electrodes in the NA, that they can control by lever pressing, will repeatedly press the lever to get stimulation in that area, which depends on dopamine being present...are they stimming?....addictive drugs and pleasurable activities like sex or eating also involve release of dopamine in the NA...does stimming by autistics involve this too? ...
the nucleus accumbens has also been implicated in attention, esp switching attention, and in schizophrenia...how might it be involved in autism?....what is the role of dopamine in that area?
...dopamine seems to have a coordinating, attention drawing, global action in the brain...bringing different areas together, a chemical connector....as opposed to glutamate the main neurotransmitter in the brain which may be more involved in local connectivity....
going along with the connectivity theory of Sophist, if autistic brains are structurally less good at long distance connections, could dopamine be a chemical facilitator that is increased in some autistics by way of compensation? Stimming could release dopamine which could help coordination and learning and so be a Good Thing, but which might also result in a system that is over-sensitive or over-used so that unwanted behaviours could break through, like tics, anxiety, paranoia...and so blocking dopamine action could help with that
compensation theories have been proposed for the role of dopamine in schizophrenia...dopamine is thought to be responsible for things like inappropriate speech and delusions and paranoia....seeing connections that are not there...and antipsychotics are pretty good at controlling these symptoms...but often that does not cure the person and they still have cognitive deficits...it has been proposed that the overactive dopamine system is a response to deficits elsewhere in the brain
in autism, perhaps it is not localised deficits so much as lack of coordinating local activities...but overactive dopamine may still be a compensatory response.
I take a low dose of stelazine, which, like haloperidol, acts by blocking dopamine receptors. I find it quite useful when I am obsessing too much, but it is by no means a cure. I was on high dose haloperidol, administered by depot injection, for about 3 years and it was baaad! At a high dose or with prolonged use, there is risk of movement disorders or you seize up and can't function well at all. I was an agitatied zombie on a high dose haloperidol, but on a low dose, I quite like such drugs.