The name is absent

80

mV, which is near the rod resting potential. These experiments demonstrate the resistance
between two cells in the network, but this is different from the coupling resistance R_c which
is between two rods. In these patch clamp experiments, current flows between all other elec-
trical paths in the network, and not just the gap junctions between two adjoining cells. When
the length constant A is short, the measured resistance using the dual patch technique will
approach the coupling resistance R_c, because the majority of the current will flow directly
between two rods.

The network resistance between two adjacent cells, referred to here as the apparent re-
sistance, R_a, is a useful parameter because it can be measured directly from the retina
without making any assumptions about the topology of the network connections or input
impedances* of individual cells. This network measurement of R_a serves as a lower bound
on the possible resistance between adjacent cells R_c. Iterative solving of a linear model of
the two-dimensional rod network shows that the actual resistance R_c should be near 10%
higher than R_a.

The network resistance and conductance (apparent resistance R_a and conductance g_a)
between cells are defined as:

Where Δ?; is the voltage difference between driver and follower cell, and i₁ is the current in
the follower cell.

*By voltage clamping each cell, the voltage across the coupling resistance through the network is held con-
stant by the amplifier, at least in the cells recorded.

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