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.