In article <C5509E.Jvx at news2.cis.umn.edu>
rogene at lenti.med.umn.edu (Rogene Eichler (Pharm-NeuroSci)) writes:
>>In article <1993Apr3.032038.14001 at Princeton.EDU> gsanders at atbat.Princeton.EDU (Gillian Denise Sanders) writes:
>>Hi. I am currently working on my undergraduate thesis on neural networks and
>>mathematical models. I have been using the backpropagation algorithm and have
>>noticed several references to its biological impausibility as one main
>>disadvatage. I am taking a brain course and our professor mentioned retrograde
>>messengers , nitric oxide and"back talking" in methods of learning such as
>>classicalical conditioning. To me this would seem to suggest that perhaps the
>>backpropagation method is not entirely biologically implausible...does anyone
>>have any information about this topic or else any references to papers which
>>discuss retrograde messengers and its backward synaptic directions? Thanks in
>>advance. Gillian Sanders
>>Backprop involves an external *teacher*, whereas the weight change via
>Nitric Oxide is a local phenomena more akin to a Hebbian type network.
>Perhaps a more plausible backprop analogy might be found in the cerebellum
>where an error signal is thought to originate from the climbing fibers
>(inferior olivary nucleus).
>
I would suggest reading the series of articles by Carlo Maggi concerning
the efferent function of afferent neurons. He is especially involved
with capsaicin-sensitive primary afferents. There are some reviews in
J. Autonomic Nervous System. Use Medline to find them (post 1980).
Tim Shickley
Dir, Neurourology
Temple University School of Medicine
(215) 221-8966/4567
FAX 221-4565
INTERNET: shickley at vm.temple.edu
BITNET: shickley at templevm.bitnet
