Abstract
The two paired giant ganglion cells (PGC's) found in each ganglion of the leech central nervous system fire synchronously in response to certain sensory input. Polarizing current passed into either of these cells is seen to displace the membrane potentials of both cells, the voltage attenuation between the two somata ranging from 2 to 5 times. This attenuation factor remains unchanged when the direction of the polarizing current is reversed, and remains about the same when the other cell of the pair is directly polarized. When one of the PGC's is partially depolarized with outward current, a repetitive train of impulses is generated. Each spike is followed by a spike in the other cell. Occasionally, a small subspike potential is seen in place of a follower spike. This potential appears to differ in shape and time course from synaptic potentials elicited by afferent input to these cells, and appears rather to be an electrotonic potential derived from the prejunctional impulse in the stimulated PGC. It is proposed that transmission between these cells is electrical, being accomplished by a flow of local circuit current across a non-rectifying junction or connection to the spike-initiating region of the other PGC.
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Selected References
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- FATT P., KATZ B. An analysis of the end-plate potential recorded with an intracellular electrode. J Physiol. 1951 Nov 28;115(3):320–370. doi: 10.1113/jphysiol.1951.sp004675. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FURSHPAN E. J., POTTER D. D. Transmission at the giant motor synapses of the crayfish. J Physiol. 1959 Mar 3;145(2):289–325. doi: 10.1113/jphysiol.1959.sp006143. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HAGIWARA S., WATANABE A., SAITO N. Potential changes in syncytial neurons of lobster cardiac ganglion. J Neurophysiol. 1959 Sep;22:554–572. doi: 10.1152/jn.1959.22.5.554. [DOI] [PubMed] [Google Scholar]
- KAO C. Y. Postsynaptic electrogenesis in septate giant axons. II. Comparison of medial and lateral giant axons of crayfish. J Neurophysiol. 1960 Nov;23:618–635. doi: 10.1152/jn.1960.23.6.618. [DOI] [PubMed] [Google Scholar]
- WATANABE A., BULLOCK T. H. Modulation of activity of one neuron by subthreshold slow potentials in another in lobster cardiac ganglion. J Gen Physiol. 1960 Jul;43:1031–1045. doi: 10.1085/jgp.43.6.1031. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WILSON D. M. The connections between the lateral giant fibers of earthworms. Comp Biochem Physiol. 1961 Nov;3:274–284. doi: 10.1016/0010-406x(61)90014-7. [DOI] [PubMed] [Google Scholar]