Table 1. Electrophysiological Properties of 3 Classes of Neurons in Layers 5/6 of Rat Prefrontal Cortex from Saline- and Cocaine-Treated Animals (Means±SEM).
|
Saline |
Cocaine |
Saline |
Cocaine |
||||
|---|---|---|---|---|---|---|---|
| FS (n=6) | NFS (n=7) | FS (n=8) | NFS (n=5) | Pyramidal (n=13) | Pyramidal (n=6) | Significant differences | |
| Input resistance (MegaOhm) | 223.4±34.7 | 262.7±66.6 | 202.6±29.0 | 241.6±29.3 | 123.9±13.5 | 162±35.6 | __ |
| Rheobase current (pA) | 145.0±32.6 | 94.3±20.2 | 142.5±30.3 | 109.0±13.9 | 137.6±12.0 | 115±11.2 | __ |
| AP threshold (mV) | −39.9±2.3 | −44.6±1.0 | −40.7±1.2 | −40.4±1.5 | −41.9±1.1 | −42.3±1.3 | __ |
| AP duration at half-width (ms) | 0.67±0.03 | 1.21±0.08 | 0.71±0.07 | 1.18±0.09 | 1.58±0.16 | 1.3±0.1 | SAL: NFS>FS** COC: NFS>FS** |
| AHP amplitude (mV) | 17.4±1.17 | 7.2±1.16 | 19.7±1.16 | 7.5±1.4 | 6.5±1.09 | 6.7±1.05 | SAL: FS>NFS** COC: FS>NFS** |
Abbreviations: AHP, afterhyperpolarization; AP, action potential; FS, fast-spiking cells; NFS, non-fast-spiking cells.
In animals from both experimental groups, FS and NFS cells differed with regard to the duration of their action-potentials at half-width and the amplitude of their AHPs. The average properties of FS cells and NFS cells did not differ when comparing cells belonging to the same class of neurons from saline- and cocaine-treated animals. Significant differences indicated by the use of Students t-tests (**p<0.01).