Posted by Cam W. on April 19, 2000, at 21:59:13
In reply to Serotonin and dopamine opposition - Railroaded, posted by Scott L. Schofield on April 19, 2000, at 11:17:42
> Nice post, Zeke. Good perspective.
1) Agreed - Cam
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> > Consider also that dopamine and serotonin also act to oppose (inhibit) themselves, eg, through autoreceptors. (Or through action: ACh 'opposes' its actions in the PNS.)
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> What is the PNS?
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2) PNS = parasympathetic nervous system - Cam> > Be careful generalizing from results of studies in persons with abnormal brain chemistry like schizophrenia. (Does a non-schizophrenic brain act like a schizophrenic brain? In schizophrenia, some dopamine circuits are hyperactive, some hypoactive.)
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> Excellent.3) In someone with schizophrenia there is a aberation in the number of dopamine receptors (too many due to a lack of synaptic pruning) or a problem with too much dopamine (perhaps resulting from the extra synapses). The basic biochemistry at the neuron works the same as in anybody. - Cam
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> > IMHO, much is to be learned from the happenings inside neurons. Along with genetics this will involve neurosteroids etc. This seems to me why antidepressants have an effective (affective) time lag whis their synaptic action is immediate.
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4) Much of the lag time for effect of antidepressants may come from several sources (eg. downregulation of beta-adrenergic receptors &/or up regulation of glucocorticoid receptors &/or resensitization of ACTH receptors in the adrenals &/or desensitization of post-synaptic serotonin recpeptors, etc. &/or etc. &/or etc.) - Cam5) &/or what you wrote below, Scott - Cam
> Definitely: neurotransmitter-stimulated adenylate cyclase-synthesized cAMP-induced protein kinase C-mediated C-FOS-directed gene transcription of G-proteins and stuff like that.
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> > Another complicating issue is the recent finding that transmission can occur electrically without any neurotransmitter (in certain processes).
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> I am curious about this. It sounds exciting.
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6) Me, too. - Cam
> > Lastly, if one transmitter inhibits the other, we can say 'oppose' or we can say 'modulate'. I tend to see DA/5HT more in the 'modulate' sense.
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> I will now be a pain in the ass:7) I doubt that, Scott; you are extremely helpful and I have gained much insight from you - Cam
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> "If a neuron using one specific neurotransmitter, or the specific neurotransmitter itself, inhibits or promotes the firing of another neuron using a different specific neurotransmitter, we cannot say 'oppose' (oppose is a two-way street). We can say 'modulate'."
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> Things are, of course, more complex than this, what with neurons using multiple transmitters or being stimulated by false transmitters and all.
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> "Railroads" obviously represents a simple analogy, but it may have utility in creating a balance of perspective against the conceptualization that the brain consists of a bunch of pools containing different colored liquids that are connected by omnidirectional aqueducts.
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8) Also, with serotonin receptors on dopaminergic neurons; GABA receptors basically on all neurons; alpha-adrenergic receptors on serotonin receptors; ad nauseum; plus the fact that there are several subtypes of receptors, some that can bind more than one neurotransmitter, makes understanding this system pure hell. I pity the poor grad student who wants to tackle this, but would definitely like to read his/her thesis. - CamCool thread, but too much thinking. You guys are fun. - Cam W.
poster:Cam W.
thread:29285
URL: http://www.dr-bob.org/babble/20000411/msgs/30626.html