Premium
Physiological properties of rod photoreceptor electrical coupling in the tiger salamander retina
Author(s) -
Zhang Jian,
Wu Samuel M.
Publication year - 2005
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2005.082859
Subject(s) - gap junction , rod , conductance , coupling (piping) , materials science , electrical synapses , biophysics , coupling coefficient of resonators , resistive touchscreen , optoelectronics , chemistry , physics , biology , condensed matter physics , composite material , intracellular , computer science , medicine , biochemistry , alternative medicine , pathology , resonator , computer vision
Using dual whole‐cell voltage and current clamp recording techniques, we investigated the gap junctional conductance and the coupling coefficient between neighbouring rods in live salamander retinal slices. The application of sinusoidal stimuli over a wide range of temporal frequencies allowed us to characterize the band‐pass filtering properties of the rod network. We found that the electrical coupling of all neighbouring rods exhibited reciprocal and symmetrical conductivities. On average, the junctional conductance between paired rods was 500 pS and the coupling coefficient (the ratio of voltage responses of the follower cell to those of the driver cell), or K ‐value, was 0.07. Our experimental results also demonstrated that the rod network behaved like a band‐pass filter with a peak frequency of about 2–5 Hz. However, the gap junctions between adjacent rods exhibited linearity and voltage independency within the physiological range of rods. These gap junctions did not contribute to the filtering mechanisms of the rod network. Combined with the computational modelling, our data suggest that the filtering of higher frequency rod signals by the network is largely mediated by the passive resistive and capacitive (RC) properties of rod plasma membranes. Furthermore, we found several attributes of rod electrical coupling resembling the physiological properties of gene‐encoded Cx35/36 gap junctions examined in other in vitro studies. This indicates that the previously found Cx35/36 expression in the salamander rod network may be functionally involved in rod–rod electrical coupling.