Electrophysiological parameters of DA and Gaba neurons in the SN and VTA
| Spike threshold | fAHP | Spike width | Ih Sag | Firing frequency | |
|---|---|---|---|---|---|
| DA (n = 55) 24/9/22 | −34 ± 1 mV | 20 ± 1 mV | 2.62 ± 0.08 msec | 39 ± 3% | 2.4 ± 0.3 Hz (n = 24) |
| Gaba (n = 24) 3/11/10 | −42 ± 1 mV | 13 ± 1 mV | 1.32 ± 0.09 msec | 9 ± 2% | 17.2 ± 3.1 Hz (n = 11) |
Number of neurons in each of the SNc/SNr/VTA is indicated below neuron class label. All quantified parameters were significantly different (p < 0.001) between DA and Gaba neurons. Fast afterhyperpolarization (fAHP) was measured from threshold; spike width was measured at threshold; Ih sag quantifies the time-dependent relaxation in the voltage response to hyperpolarizing current steps, indicative of Ihcurrent activation; firing frequency was evaluated at the resting membrane potential in spontaneously active neurons.