Table 1.

Electrophysiological properties of 4 neuron types in naive rats

	Phasic	Tonic	Onset	Random
Resting membrane potential, mV	−55 ± 0.6	−62 ± 0.9	−52 ± 1.2	−57 ± 1.7
Membrane resistance, GΩ	2.2 ± 0.3	1.6 ± 0.2	1.8 ± 0.4	0.8 ± 0.1
Capacitance, pF	42 ± 1.4	67 ± 3.5	49 ± 4.8	64 ± 6.8
Spontaneous firing	65% (73/112)	94% (73/78)	0% (0/23)	37% (7/20)

Values are means ± SE. Number of neurons recorded (n_total = 233; n_male = 101, n_female = 121): Phasic (n_total = 112; n_male = 50, n_female = 56), Tonic (n_total = 78; n_male = 37, n_female = 38), Onset (n_total = 23; n_male = 7, n_female = 15), and Random (n_total = 20; n_male = 7, n_female = 12). Significant differences were identified in resting membrane potential (1-way ANOVA, F_3,227 = 19.45, P < 0.0001; Tukey’s multiple comparisons; Phasic vs. Tonic, P < 0.0001, Tonic vs. Onset, P < 0.0001, Onset vs. Random, P < 0.04), with no significant differences in resting membrane potential between males and females among these neuron types (2-way ANOVA, F_1,212 = 2.12, P = 0.15). No significant differences were observed in the membrane resistance of these neuron types either when grouping males and females together (F_3,219 = 2.54, P = 0.06) or when looking at sex as a factor (F_1,205 = 0.02, P = 0.88). Differences in capacitance were identified (F_3,218 = 18.49, P < 0.0001; Tukey’s multiple comparisons test; Phasic vs. Tonic, P < 0.0001, Phasic vs. Random, P = 0.001, and Tonic vs. Onset, P = 0.01), with no further differences between males and females (F_1,202 = 0.03, P = 0.86). Spontaneous firing is given as an overall percentage, with the exact number of neurons firing at rest over the total number of that type of neuron shown in parentheses.