Biophysical Journal 44: 91-99 (1983)
© 1983 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Yang, J Articles by Chapman, K M Search for Related Content PubMed PubMed Citation Articles by Yang, J Articles by Chapman, K M

Frequency domain analysis of electrotonic coupling between leech Retzius cells.

ABSTRACT

Transfer functions of the input impedance Z(f) and coupling ratio H(f) were measured from the paired Retzius cells of leech segmental ganglia, using sinusoidal and pseudorandom test test currents. The data were compared with two classes of linear electric circuit models of electrotonic coupling, one with a purely resistive junction, and the other with a finite equivalent cable coupling the two somata. Model simulations suggested the phase behavior of the coupling ratio as a sensitive discriminator between these two cases. For resistive coupling, the phase of the coupling ratio asymptotically approaches -90 degrees at high frequencies, while for a cable segment, at least 0.5 length constants in length, it crosses -90 degrees with a definite negative slope and continues to more negative values. Measured phase lags of the coupling ratio in Retzius cell preparations consistently exceeded -90 degrees at frequencies above 50 Hz, and phase plots crossed -90 degrees with significantly negative slopes. We conclude therefore that a significant cable segment contributes to the coupling between Retzius cell somata.

This article has been cited by other articles:

				M. G. Maltenfort, C. A. Phillips, M. L. McCurdy, and T. M. Hamm Determination of the Location and Magnitude of Synaptic Conductance Changes in Spinal Motoneurons by Impedance Measurements J Neurophysiol, September 1, 2004; 92(3): 1400 - 1416. [Abstract] [Full Text] [PDF]

				E. Garcia-Perez, M. Vargas-Caballero, N. Velazquez-Ulloa, A. Minzoni, and F. F. De-Miguel Synaptic Integration in Electrically Coupled Neurons Biophys. J., January 1, 2004; 86(1): 646 - 655. [Abstract] [Full Text] [PDF]

				F. F. De-Miguel, M. Vargas-Caballero, and E. Garcia-Perez Spread of synaptic potentials through electrical synapses in Retzius neurones of the leech J. Exp. Biol., January 10, 2001; 204(19): 3241 - 3250. [Abstract] [Full Text] [PDF]