Fig. 6.

R-LM and P-LM cell morphological features.a, R-LM cell. As was typical of this interneuronal subtype, this R-LM cell had a pyramidal-shaped somata from which three primary dendrites emanated. This cell also had relatively smooth primary dendrites (large arrows), which then became quite varicose after the first dendritic branchings (arrowheads). The axon initial segment can also be seen emanating from a primary dendrite (small arrow).b, P-LM cell. Note the axon that emanated from the primary dendrite, which projected toward SLM. c, R-LM and P-LM cell dendrites generally do not enter SLM. This example shows an R-LM cell dendrite that abruptly turned away from SLM at the SR-SLM border. In this case, the dendrite did not enter SLM. In numerous other cases, the dendrites would enter the most proximal portion of SLM before turning back. For all three images, SO is above, and SLM is below. Strata abbreviations are the same as in Figure 2. Scale bars:a–c, 40 μm.