Electrophysiological and morphological characteristics of striatal MS neurons and striatal FS interneurons
| MS neuron (n = 14) | FS interneuron (n = 12) | |
|---|---|---|
| Days in vitro | 48 ± 4 | 40 ± 3 |
| Electrophysiology | ||
| Resting potential (mV) | −75 ± 2 | −64 ± 2* |
| Input resistance at rest (MΩ) | 121 ± 11 | 87 ± 12 |
| Membrane time constant1-a (msec) | 13 ± 1 | 8 ± 1** |
| Spike threshold1-b (mV) | −46 ± 1 | −45 ± 3 |
| Spike overshoot (mV) | 2 ± 2 | −13 ± 3** |
| Spike amplitude1-c (mV) | 47 ± 2 | 29 ± 2* |
| Spike half width1-d(msec) | 1.4 ± 0.1 | 0.7 ± 0.1* |
| Max rise of spike (V/sec) | 104 ± 12 | 95 ± 13 |
| Max fall of spike (V/sec) | −40 ± 4 | −55 ± 7 |
| Ratio of max rise/max fall | 2.6 ± 0.2 | 1.8 ± 0.1 |
| Max of AHP(mV) | 10 ± 1.3 | 14 ± 2 |
| Time of AHP (msec) | 8.6 ± 1.3 | 4.1 ± 0.6* |
| Morphology | ||
| Somatic cross-sectional area (μm2) | 93 ± 16 | 200 ± 23* |
| Somatic cross-sectional area | 12 ± 1 | 19 ± 1* |
| Long axis (μm) | ||
| Somatic cross-sectional area | 9 ± 1 | 13 ± 1* |
| Short axis (μm) | ||
| Number of primary dendrites | 5.4 ± 0.3 | 3.3 ± 0.4* |
| Dendritic area (μm2) | 37,400 ± 7,500 | 96,300 ± 22,200* |
| Dendritic area long axis (μm) | 261 ± 17 | 453 ± 53* |
| Dendritic area short axis (μm) | 179 ± 23 | 280 ± 48* |
Results are mean ± SEM. (Mann–Whitney U test; *p < 0.05; **p < 0.005).
↵F1-a Linear regression analysis within ±5–10 mV from resting membrane potential.
↵F1-b Measured using depolarizing current pulses from resting potential.
↵F1-c Spike threshold to spike peak.
↵F1-d Action potential started when the rising rate exceeded 5% of its maximum value.