Randy copied the correspondence he had with Dr. Casida, and that is helpful.  It could have been an oral communication and the fact that he has an email is great.

What that email tells me is that the IMI is a strong agonist but just as the paper Ghislain forwarded says, it can be displaced by an even stronger agonist or antagonist (meaning it can be dislodged from the AChR).  So, the IMI will stay bound to each receptor for a long time but will bounce off on its own occasionally, and then bind again quickly, according to a steady-state relationship between the free molecules and the bound ones in the synapse.  There won't be many free molecules, but if they are able to eventually diffuse out of the synaptic cleft (assuming that the surrounding tissue concentrations become lower) then fewer IMI will be bound to the postsynaptic membrane.  In that sense the effect is "reversible", and so it comes down to a) how long does the active chemical hang around in the tissues, b) how fast does it diffuse in or out? and c) how long is the exposure?   Have any of these things has been made clear yet for honey bees?

Also, agonists interfere with receptor function by blocking them open, and antagonists interfere with their function by blocking them closed.

I really hope this settles the issue as far as what I've been saying about neuron synapses and their receptors....it's finally thawing here, classes are ending, and I want to go tend my bees and not hammer on this anymore.  I tried my best.

Up with bees!

Christina

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html