Interneurons and synaptic symmetry

Matthew Kirkcaldie m.kirkcaldie at removethis.unsw.edu.au
Mon May 3 04:03:17 EST 2004


In article <Xns94DED361E7D34BilZ0rhotmailcom at 202.20.93.13>,
 BilZ0r <BilZ0r at TAKETHISOUThotmail.com> wrote:

> So bassically, there are more psd-95-esque proteins associated with 
> excititory receptors?

I wouldn't hazard a guess as to what the PSD is composed of specifically 
- for instance, the LTP/D related cycling of AMPA receptors to and from 
the synaptic surface may involve structures buried in that PSD as well 
(and all the clathrins, etc, involved in the cycling itself).  I know 
some people have fractionated the synapses out and I'm sure someone has 
done a Western or a 2D gel on them, there must be references out there.

> In one of the papers, it says that some of the 
> synapses in question are assymetric, but then contain dense-core 
> vesicles, which under my understanding ment monoamine. What is the likely 
> explanation there? That we have co-release, or that certain monoaminergic  
> postsynaptic densities can be rather large?

Well of course it depends on the one synapse, one transmitter dogma - if 
the vesicles are monoamine-containing then I would guess that adrenergic 
or dopaminergic synapses are also asymmetric - after all, if we're going 
to lump them into two groups then the minor transmitters must be in one 
or the other!  I guess co-release is an option which must be entertained 
but I have no idea if there is any evidence for it.

Of course, the associations made between EM structures and biochemistry 
may not be hard and fast, either; not an expert by any stretch of the 
imagination!

      Cheers,

         Matthew.



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