In article <3rl08k$107u at news.ccit.arizona.edu>, sfm at manduca.neurobio.arizona.edu (Stephen Matheson) writes:
>From article <3ris4k$65i at eldborg.rhi.hi.is>,
>by thoreys at rhi.hi.is (Thor Eysteinsson):
>>DvorakH at starbase1.caltech.edu (Hannah Dvorak) writes:
>>>In article <8AB22AA.0E53000E32.uuout at dkb.dk>, lars.thomsen at dkb.dk (LARS
>>>> I was wondering if any one remembered good examples of
>>>> sensory neurones with the cell bodies close to the
>>>> location of the stimulus.
>>> I would say that nocireceptors (Pacinian corpuscles, Merkels disks,
>> etc.) were close to the stimulus,
>They are indeed, but they are not neurons. As I seem to
>recall, these receptors are composed modified connective-tissue cells,
>and are *innervated* by sensory neurons with distant cell bodies.
>The generator potential occurs in the dendrite(s) of the sensory
while it is true that nociceptors have cell bodies which lie remote to the site
of stimulation, it isn't the case that nociceptors *are not* neurons.
nociceptors (A-delta and C-fibers) are indeed neurons with their cell
bodies lying remote of site of stimulation (this is according to the last
i read, which i believe was a modified gate-theory paper by melzack).
a receptor, by definition as the transductory apparatus, must be a neuron, and
*all* receptors are neurons. there are, however, several cases where receptors
function in conjuntion with non-neural tissue (e.g., merkel's disc), but the
non-neural component is *not* the receptor.
>Similarly, gustatory cells in taste buds are made of modified
>epithelial cells (I think), and again are innervated by cranial
>sensory neurons in somewhat distant ganglia.
again, gustatory receptors are innervated by the 7th cranial (as already
alluded to) but are indeed the neuron/receptor that converts the chemical
stimulus into an electrical message. they are packed in taste buds, but i
would say that they are proximal to the stimulus. gustatory receptors are