Sunday, October 14, 2012

SfN Neuroblogging 2012: weird receptors

Day 2 of SfN was so packed with awesome science that I have too much to blog about.

here are two highlights:
NMDA receptor (source)

1. A great special lecture by C. Luscher about drugs and synaptic plasticity introduced me to the concept of a calcium impermeable NMDA receptor. As far as I was concerned, calcium permeability was a defining characteristic of the NMDA receptor. Luscher explained that after cocaine exposure (I don't remember how much or how long an exposure), there was a shift in AMPA receptor type from calcium impermeable to permeable. AND a corresponding shift in NMDA recepter type from calcium permeable to impermeable.

2. A poster (236.14) presented by M. Markham on the weakly electric fish introduced me to the sodium activated potassium channel. I was familiar with calcium activated potassium channels, but a sodium activated potassium channel allows the action potential in the electric fish to repolarize super quickly to facilitate very high frequency firing.  Other species of electric fish do not have these channels and do not use such high frequencies.
But here's the really interesting thing: People (and mammals in general) do have these channels (236.17). In fact a mutation in this channel in humans leads to serious serious central nervous system problems.
And here is the even more interesting part. In humans these channels aren't used to create super fast firing frequencies. It is more likely that they trigger essential intracellular signaling cascades.

UPDATE 11/13/12: for more on the sodium-activated potassium channels (SLICK and SLACK) and how they help the auditory system fire precisely, see this new post.

Again, more details will follow SfN and I will post more highlights from today tomorrow.

© TheCellularScale

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