Table 1.

Electrophysiological properties of striatal EGFP–TH+ interneurons in adult mice

ParameterType I (84)Type II (18)Type III (8)Type IV (29)
Input resistance (MΩ)744 ± 33a,b,c (346 to 1500)429 ± 39 (234 to 758)180 ± 8f (150 to 205)471 ± 30 (235 to 821)
n = 78n = 17n = 8n = 29
Resting membrane potential (mV)−71 ± 1a,b,c (−50 to −85)−77 ± 1d (−62 to −82)−89 ± 1 (−86 to −94)−74 ± 1f (−55 to −82)
n = 79n = 18n = 8n = 29
AP threshold (mV)−43 ± 0.3a (−38 to −50)−47 ± 0.5e (−42 to −50)−45 ± 0.6 (−42 to −47)−44 ± 0.5 (−39 to −48)
n = 81n = 17n = 8n = 29
AP width 50% (ms)0.78 ± 0.03a,b,c (0.4 to 1.9)0.43 ± 0.01 (0.3 to 0.53)0.46 ± 0.01 (0.4 to 0.5)0.5 ± 0.02 (0.4 to 0.85)
n = 81n = 17n = 8n = 29
AP amplitude (mV)76 ± 1.3a (52 to 101)94 ± 2d,e (86 to 116)79 ± 2 (70 to 88)80 ± 1 (63 to 91)
n = 81n = 17n = 8n = 29
AHP amplitude (mV)16 ± 0.4a (7 to 24)20 ± 0.6d,e (16 to 25)14 ± 0.3 (13 to 16)15 ± 0.5 (10 to 24)
n = 81n = 17n = 8n = 29
Maximum number of AP (150–200 pA)7 ± 0.6a,b,c (2 to 22)53 ± 2d,e (45 to 68)14 ± 1f (9 to 17)28 ± 1 (18 to 45)
n = 53n = 14n = 8n = 23
Maximum frequency (Hz)114 ± 9a,c (32 to 256)194 ± 10d,e (137 to 265)98 ± 6f (66 to 124)321 ± 6 (276 to 386)
n = 53n = 14n = 8n = 23
Spontaneous activity10 of 844 of 180 of 81 of 29
Plateau potential duration (ms)255 ± 31 (46 to 1250)150 ± 116 (15 to 381)159 ± 41 (119 to 200)0 of 26
39 of 843 of 122 of 8
LTS component0 of 844 of 180 of 829 of 29
Ih ratio1.12 ± 0.01 (1.03 to 1.54)1.12 ± 0.02 (1.05 to 1.2)1.13 ± 0.02 (1.02 to 1.3)
44 of 8411 of 180 of 817 of 29
  • All values are means ± SEM. Numbers in parentheses refer to the range of values. n refers to number of neurons from which the measurements were obtained. AP, Action potential; AHP, afterhyperpolarization. One-way ANOVA revealed a significant difference effect of type for all parametric measurements. Bonferroni's post hoc comparisons were run to determine specific type to type differences.

  • aType I versus Type II; bType I versus Type III; cType I versus Type IV; dType II versus Type III; eType II versus Type IV; fType III versus Type IV.

  • a,b,c,d,e,fp < 0.001.

  • a,b,c,d,e,fp < 0.05.