Figure 3.

Dopamine-evoked extraburst spikes are peripherally initiated. The peaks of spikes in the intracellular soma recordings (vertical dashed line) were used to trigger multiple sweeps of nerve recordings. A, Burst spikes initiated in the STG reached the soma and the dvn at approximately the same time and traveled with increasing delay down the lvn and vlvn to the pdn. The mean delay ± SD between the soma and the pdn was 34.3 ± 3.4 msec (n = 6). B, Extraburst spikes appeared first in the dvn, then in the lvn, and then in the soma. The delay between dvn and lvn was much shorter than in burst spikes, indicating a spike initiation zone between the dvn and lvn recording sites. The mean delay between soma and pdn was 11.8 ± 2.8 msec (n = 6). The delays in A and B were statistically different (paired t test, p < 0.001).