Randy says:

"You asked the question "and why not."  Pete answered it correctly--there is no reason to assume that the responses will be the same."

Sorry, Randy.  You are wrong too.  You just don't understand receptor physiology.

You said,

"The nAChR's are distributed differently in insects,"

I've found references all over the place on this. However, their distribution is not relevant to the question of how they respond to the ligand.

Randy says:

"and the neonics are specifically built to produce different responses."

This is simply WRONG.   They produce EXACTLY the same response, because they bind to nicotinic receptors and these are physiologically similar in insects and mammals.

Randy says:

"you can simply read Wikipedia to find that:

"These receptors are located in both the central and peripheral nervous systems of mammals but are limited to the CNS in insects.  Because most neonicotinoids bind much more strongly to insect neuron receptors than to mammal neuron receptors, these insecticides are selectively more toxic to insects than mammals.

The [imidacloprid] molecule shows weak affinity to mammalian nAChRs but strong affinity for insect nAChRs. Furthermore, the uncharged molecule can penetrate the insect blood–brain barrier, while the human blood–brain
barrier filters it"

Wiki is right.  But this doesn't make anything I said wrong.  It would help if you understood some physiology here, Randy.

Randy ends with:

"I'm not going to even respond to your tart criticisms of Peter's other polite and accurate statements.  We are not here to be insulted--we are here for thoughtful discussion!"

I thought I was polite too.  It appears you've made your mind up about why I am participating in this discussion.  I wanted to correct the misinformation Pete (and now you) are spreading due to your poor understanding of receptor physiology.  If you read that as "insulting"...well....I don't.

I don't expect that you will know everything about biology, and I think it is helpful to correct conceptual inaccuracies when I see them.   Do you feel that it is inappropriate to correct you on topics where you don't have a clear picture on what is going on?

Let me be perfectly clear.  I am not saying there is no difference in receptor selectivity...I am saying that nicotinoid receptors have the same functions in both insects and humans (and other vertebrates).

Christina

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