Electrical properties of the squid axon sheath.

The first impedance data on the squid giant axon gave a lossy membrane capacity of 1 muF/cm2 from 1-200 kHz. The remaining observations of one experiment up to 5 MHz were not included in the simple conclusions and have now been ascribed to the mostly Schwann cell sheath. The results of these fragmentary data, 1.6 omega-cm2 and 12.5 membrane layers, are within the range of recent current clamp and electron microscope conclusions to give them independent confirmation and support.