Randy, this is what Bayer published when imidacloprid was introduced to the US market in 1991. They retracted the key message of course after my 2010 publication, but it is a fact that nAChRs are blocked by imidacloprid, otherwise there would be no insecticidal action.

 

The biochemistry of imidacloprid  [1991]

Abbink, J. (Bayerwerk A.G., Wuppertal-Elberfeld (Germany). Pharma-Forschungszentrum)



Abstract:
Imidacloprid belongs to the group of nitroguanidines. Many representatives of this class of compounds, and imidacloprid in particular, have an excellent insecticidal action. This high activity is brought about by binding of imidacloprid to the nicotinergic acetylcholine receptor in the insects's nervous system, which interferes with chemical signal transmission. Methods for isolating nicotinergic acetylcholine receptors from the heads of Stomoxys calcitrans and for measuring the binding affinity, if any, of a substance on such receptors have been developed. The neurophysiological properties of the nicotinergic acetylcholine receptors of Stomoxys calcitrans, which include the binding of imidacloprid, are described in detail. Imidacloprid is the first highly effective insecticide whose mode of action has been found to derive from almost complete and virtually irreversible blockage of postsynaptic nicotinergic acetylcholine receptors in the central nervous system of the insect pest Stomoxys calcitrans

 

Pflanzen.-Nachr. Bayer 1991 Vol 42 (183-195)

 

I am saying no more than what Bayer said in 1991.

 

Henk

 

Van: [log in to unmask] [mailto:[log in to unmask]] Namens randy oliver
Verzonden: maandag 26 oktober 2015 14:40
Aan: Informed Discussion of Beekeeping Issues and Bee Biology
CC: ETS Nederland
Onderwerp: Re: [BEE-L] neonics and honey bee health...

 

Note to all,

 

I feel that it is really important that we understand any long-term or cumulative effects of chemical exposure (such as the clear adverse effects of  exposure to heavy metals), and for the purposes of this thread, those of neonicotinoids specifically.

 

Christina, when I ask you for supportive evidence for the hypothesis, the reason is that I'm assuming that you are promoting that hypothesis due to already having evidence at hand (such as published studies or your own research).  

 

I don't want you to take that request as an adversarial challenge to "prove" anything.  I'm not here to win an argument--I'm interested better understanding what has been discovered, or exactly what kind of research needs to be done to answer that question.

 

I appreciate having you in this discussion due to your expertise in neurology.  We also have a few other posters to the list with expertise in toxicology, chemistry, and pharmacology.  And this is why I invited Dr. Tennekes to join the discussion.  I've been following the "cumulative effects hypothesis" since he proposed it, and have previously corresponded at length with another of his coauthors (Henk, I'm cc'ing you again, but please subscribe to the List to join this discussion from this point on).

 

So why don't we carefully review the scientific (as well as on-the-ground) evidence to date as to the long-term effects of the strong binding affinity of neonics on either individual honey bees, honey bee colonies, or other organisms?  But let's not waste the List's time.  I suggest that we cite actual data--not papers in which someone is citing someone else's opinion.

 

-- 

Randy Oliver

Grass Valley, CA

www.ScientificBeekeeping.com


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