Posted by Dopamine123 on March 11, 2008, at 17:33:25
In reply to Re: SULPIRIDE » dopamine123, posted by tensor on March 6, 2008, at 23:56:52
>So how many(currently known) DA recptors are presynaptic and which are autorecptors? I was under the impression that there was only one autoreceptor for negative feedback.
I think "presynaptic" and "autoreceptor" are basically synonyms. From what I have read, I think only D2 and D3 receptors exist as autoreceptors. D1, D4 and D5 exist solely as postsynaptic receptors.
http://www.springerlink.com/content/g6513079543465w5/http://www.nature.com/npp/journal/v23/n5/full/1395548a.html
>"It is known that D2/D3 autoreceptors are enriched in the SN and the VTA and that systemic or local administration of D2/D3 agonists into these structures significantly reduces the firing rate of dopaminergic neurons">"Also, what is the relation between e.g. presynaptic DA2 and postsynaptic DA2 given that they share the same name?"
They share the same structure, and they activate the same intracellular cascade (inside the neuron).
http://www.ncbi.nlm.nih.gov/pubmed/9457173
>"The diverse physiological actions of dopamine are mediated by at least five distinct G protein-coupled receptor subtypes. Two D1-like receptor subtypes (D1 and D5) couple to the G protein Gs and activate adenylyl cyclase."
poster:Dopamine123
thread:815882
URL: http://www.dr-bob.org/babble/20080303/msgs/817404.html