Appropriate “negative” resistance of the nonsynaptic HC membrane was described by Byzov et al. [6] in ide and pike retinas. This nonlinearity of the HC membrane is accounted for so-called “anomalous rectification” in K⁺ channels, but its function was remained unclear.
          The figure below taken from the paper [7] represents a set of IV-curves measured in HCs of various animals. An encircled diagram (d) illustrates an N-shaped IV-curve resembling the “theoretical” one shown in p.10.