Term: class B neuron

Definition: The second group of cells seen in our Golgi material (class B of Grossman et al. 1973; Fig. 2) typically had small somas (10 microns) and only 2 to 3 primary dendrites which often extended several hundred microns from the soma. These primary dendrites usually branched only once and the secondary dendrites were rarely seen to branch. Thin, axon-like processes were occasionally seen arising from these cells (Fig. 2), but they could not be traced for any distance and could not be positively identified as axons. Class B cells were most commonly seen in the lateral portions of the nucleus, and their dendritic arbors were typically oriented parallel to the lateral border of the LGN. When members of this class had somas located away from the borders of the LGN, the orientation of their dendritic arbors was less pronounced (Fig. 2).