Electrotonic coupling between neurons in cat inferior olive.

Blockade of Brain Stem Gap Junctions Increases Phrenic Burst Frequency and Reduces Phrenic Burst Synchronization in Adult Rat

“…We interpret these findings to suggest that blockade of gap junctions produced an overall reduction or loss of synchronization within an inspiratory burst. This explanation seems reasonable since neuronal gap junctions are proposed to play a role in synchronization of neuronal activity (Bennett 1997;Christie et al 1989;Jefferys and Haas 1982;Llinás et al 1974) as well as in the generation of oscillatory neuronal activity and synchronization of spontaneously produced high-frequency oscillations (Bleasel and Pettigrew 1992;Buzsáki et al 1992;Draguhn et al 1998;Llinás and Yarom 1986). It should be noted, however, that computational models of oscillatory neuronal networks have also shown that although strong electrotonic coupling between neurons synchronizes electrical oscillations between cells, weak electrotonic coupling can phase-lock cells (Moortgat et al 2000;Sherman and Rinzel 1992); thus the difference between the observed modulation of spectral composition in our current investigation and those of Bou-Flores and Berger (2001) may be explained the differences in the strength of coupling under the experimental conditions employed.…”

Topography and Response Timing of Intact Cerebellum Stained With Absorbance Voltage-Sensitive Dye

“…In other species, there is evidence that IO normally provides a synchronous output arising from gap junctions observed there , which may mediate electrotonic coupling between IO neurons (Chorev et al 2007;Devor and Yarom 2002;Leznik and Llinás 2005;Llinás et al 1974;Long et al 2002). Complex spike synchrony was observed in sagittally oriented groups of PCs but there was almost no cross-correlation of complex spikes of PCs oriented transversely (Sasaki et al 1989).…”

Voltage-Dependent Enhancement of Electrical Coupling by a Subthreshold Sodium Current

“…Most of the electrical coupling in mammalian neurons takes place at remote dendritic sites (Llinás et al, 1974;Peinado et al, 1993;De Zeeuw et al, 1995;Kosaka, 2000, 2003) between dissimilar tortuous neuronal processes in which geometry, despite the presence of bi-directional gap junction channels, might challenge efficient bi-directional communication. Unilateral or asymmetric amplification of weaker electrical coupling by intrinsic membrane properties in one of the coupled cells might act to promote synchronized neuronal activity, by ensuring bidirectional communication between neuronal dendritic processes of different size and shape.…”

“…Thus, in addition to the control of gap junctional conductance itself (Furshpan and Potter, 1959;Auerbach and Bennett, 1969;Piccolino et al, 1982;Lasater and Dowling, 1985;Yang et al, 1990;Pereda et al, 1992Pereda et al, , 1998, changes in the conductance of the nonjunctional membrane are known to have a profound impact on electrical coupling (Kandel and Tauc, 1966;Spira et al, 1976;Zipser, 1979). In the mammalian CNS, neuronal gap junctions are often localized between small dendritic processes of dissimilar size and shape (Llinás et al, 1974;De Zeeuw et al, 1995;Fukuda and Kosaka, 2000;Fukuda and Kosaka, 2003) where geometry may favor transmission in one direction or the other. Recent evidence showed that amplification of electrical coupling by intrinsic membrane properties (Mann-Metzer and Yarom, 1999;Schmitz et al, 2001) plays an essential role in promoting the synchronization of weakly coupled neuronal networks (Traub, 1995;Mann-Metzer and Yarom, 1999), suggesting a role for voltage-dependent membrane properties in regulating transmission at electrical synapses.…”