Organization of ADVR 
131 
PDVR 
BS THAL 
Figure 11. Current concept of the organization of snake ADVR. A sector of ADVR similar to that shown in 
Figure 2 is depicted diagramatically. The boundaries of ADVR zones are shown on the left. The somata 
of ADVR neurons as they appear in Nissl preparations are shown by open profiles. Neurons representa- 
tive of those present in each zone are depicted as they appear in Golgi preparations. Type 1 and type 3 
axons are shown as they appear in Golgi preparations. The axon of a zone D neuron is depicted crossing 
the ventral border of ADVR. Lesions which involve these neurons produce degeneration in the medial 
striatal nucleus (MS), intrapeduncular nucleus (IP), perifascicular complex (PF), and posterior dorsal 
ventricular ridge (PDVR). The distribution of degeneration following lesions of the brainstem (BS) and 
thalamus (THAL) are shown by the stippled bars on the right. 
