Fig. 3.

Spike attenuation and reflection occurs within the lateral process. A, Schematic representation of the neuron from which the data in B–D were obtained. One electrode was in the soma (S), and two electrodes were in the lateral process (NL, near lateral;FL, far lateral). B1, B2, B21 was peripherally activated at its resting potential (first part of record). Note that spikes were most attenuated at the far lateral site. Depolarizing current was injected into the soma (barunder bottom trace) and spikes became full-size at the lateral recording sites, indicating that the lateral process was not damaged. C1, C2, High-speed record of1 and 2 in B. Each stimulus triggered two spikes in B21. When full-size spikes were recorded at the far lateral site, spikes at the near lateral and soma sites were increased in amplitude and half-width (e.g., the left spike in 2). Da–Dd, Superimposition ofa–d from C. The effect of spike initiation at the far lateral site was more pronounced at the near lateral site then it was in the soma (i.e., the difference betweena and b is more than that betweenc and d).