Table 1.

Electrophysiological characteristics of striatal spiny projection neurons and fast spiking interneurons in cortex-striatum-substantia nigra cultures

Characteristics	Spiny projection neuron (n=16)	Fast spiking interneuron (n=7)
Down-state potential (mV)	−79.2 ± 1.9	−64.5 ± 3.3**
Input resistance (MΩ)a	341 ± 36	287 ± 60
Spike amplitude (mV)b	61.5 ± 2.4	57.1 ± 5.0
Spike width (msec)c	1.51 ± 0.09	0.83 ± 0.05
AHPmax (mV)	14.1 ± 0.8	17.3 ± 2.0
Time to AHPmax (msec)	8.8 ± 0.4	4.8 ± 0.6**
Latency to first spike (msec)d	379 ± 25	199 ± 28

Results are mean ± SEM (MANOVA:F = 18.74;p = 0.001;^**ANOVA on time to AHP_max:F = 33.62;p<0.0001; ANOVA on down-state potential:F = 15.03;p = 0.0019). Spike width and latency to first spike were used to classify neurons; thus, ANOVA is inappropriate on these characteristics.

^a Measured using depolarizing and hyperpolarizing current pulses from down-state potential.

^b Spike threshold to spike peak.

^c Action potential width measured at half of spike amplitude.

^d Maximal observed latency in response to 500 msec current pulses at various current strengths.