Peptides in Neuronal Function: Studies Using Frog Autonomic Ganglia
- Y.N. Jan,
- C.W. Bowers,
- D. Branton,
- L. Evans, and
- L.Y. Jan
This extract was created in the absence of an abstract.
Excerpt
At present, more than 20 peptides are considered as putative neurotransmitters, based primarily on their localization in nerve terminals and their actions on nerve cells (Hökfelt et al. 1980). The list is almost certainly not exhaustive and it is likely that more will be found in the future. If many peptides turn out to be neurotransmitters, one might wonder why the nervous system utilizes so many different transmitters. A detailed analysis of the action of a number of neuropeptides may reveal characteristics unique to peptidergic transmission and thus shed light on the functional significance of peptide transmitters and perhaps explain the need for multiple transmitters.
Frog sympathetic ganglia and parasympathetic cardiac ganglia are excellent preparations for this purpose (Langley and Orbeli 1910; McMahan and Kuffler 1971). Structurally, they are very simple. Neurons in these ganglia are unipolar and have no dendrites. Preganglionic fibers make synaptic contacts almost exclusively on the...
