gmsizemore2 at yahoo.com (Glen M. Sizemore) wrote in
news:6e2f1d09.0406170830.1ca99238 at posting.google.com:
> GS: But I think that a lot of these studies are looking at changes in
> the VTA, NAcc, VP etc. as a function of extended exposure to drugs.
> No? I don't think the notion ever was "this is where the learning
> takes place." Indeed, I'm not sure most people regard "addiction" as
> primarily a learning phenomenon. Certainly, learning to
> self-administer a drug puts one on the road, and it is clear that
> (most) drugs of abuse (DOA) function as reinforcers in non-humans, but
> the notion is that the whole motivational system goes out of whack as
> a function of repeated self-administration (and the neurochemistry is
> different when the drug is self-administered at least with cocaine).
No, I think a lot of people are looking at changes in the VTA being
responsible for the learning, they're not putting it forward blatantly
yet, but putting it as questions. For instance "It is not clear, however,
if these early alterations in VTA function act solely as a transient gate
to permit downstream changes or play a more significant long term role in
the persistent changes that underlie drug-craving"..."Enhanced
glutamatergic transmission at VTA synapses may also produce long-term
changes in the VTA itself that contribute to relapse to drug use."
Both from Annu Rev Physiol. 2004;66:447-75
> GS: Hmmm .yes, I suppose that recording from cells while an animal is
> behaving is worthwhile, but the problems with much of behavioral
> neuroscience, IMO, is largely its conceptual structure. My guess is
> that "goal cells" will eventually be seen as a silly notion, as will
> representation (but not "mapping") and a host of other things borrowed
> from our folk-psychology vernacular. No offense intended.
Well it all gets rather philosophical doesn't it. I mean, science has
never worked like how philosophers would like it to, and it never will.
Research asking the 'wrong' questions should still come up with useful
results, so in my mind, even if someone is experimenting on the brain
with completely a whack hypothesis, the results shouldn't care what he
thinks.
Meanwhile, whether or not "goal cells" make any sense, or whether we
should be talking about "goal arrays" or "goal recursive neuronal
circuitry", if you find a correlation between two things (cell spiking
and behavior) whether its causative or not, it is going to tell you
something.