Table 1.
Electrophysiological properties of accumbens neurons
|
|
Nucleus accumbens shell |
Nucleus accumbens core |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
|
Sensitized |
Nonsensitized |
Saline |
Sensitized |
Nonsensitized |
Saline |
||||
| n (cells/animals) | 4/4 | 5/5 | 5/5 | 14/13 | 5/4 | 8/8 | ||||
| Membrane potential (mV) | ||||||||||
| Down state | −87.3 ± 7.9 | −83.8 ± 9.4 | −82.6 ± 8.0 | −85.8 ± 7.3 | −88.5 ± 2.5 | −83.6 ± 4.8 | ||||
| Up state | −71.8 ± 10.4 | −73.1 ± 6.7 | −67.5 ± 6.1 | −69.1 ± 7.2 | −70.8 ± 6.1 | −69.0 ± 8.7 | ||||
| Time in up state (%) | 58.2 ± 9.4a | 33.3 ± 20.3a | 50.3 ± 9.5 | 42.7 ± 11.8 | 41.7 ± 13.9 | 39.1 ± 10.2 | ||||
| Input resistance (MΩ) | 53.8 ± 16.9 | 75.4 ± 29.8 | 83.0 ± 40.4 | 85.4 ± 26.9 | 104.7 ± 28.0 | 83.0 ± 17.9 | ||||
| Time constant (τ) (ms) | 5.9 ± 1.7 | 3.9 ± 1.4 | 5.2 ± 0.9 | 5.2 ± 1.7 | 5.2 ± 1.8 | 5.5 ± 1.4 | ||||
| Spike threshold (mV) | −48.3 ± 4.1 | −45.4 ± 5.5 | −48.0 ± 5.2 | −49.7 ± 4.3b | −52.6 ± 2.6b | −43.7 ± 6.8b | ||||
| Spike duration (ms) | 2.4 ± 0.3c | 1.8 ± 0.2c | 2.1 ± 0.3 | 2.2 ± 0.4b | 2.1 ± 0.1b | 2.9 ± 0.9b | ||||
| Rheobase (nA)* | 0.30 ± 0.08 | 0.23 ± 0.06 | 0.25 ± 0.13 | 0.30 ± 0.05 | 0.22 ± 0.13 | 0.36 ± 0.11 | ||||
| Firing rate (Hz) | 0.90 ± 0.93 | 0.13 ± 0 | 1.55 ± 0 | 1.01 ± 1.24 | 2.25 ± 0.64 | 1.02 ± 0.13 | ||||
|
|
(n = 2/4) |
(n = 1/5) |
(n = 1/5) |
(n = 5/14) |
(n = 2/5) |
(n = 2/8) |
||||
All values are mean ± SD.
Independent t test: ap < 0.06; bp < 0.05; cp < 0.02 versus saline.
*
Main effect of group, p < 0.05; independent t test, nonsensitized versus sensitized (p < 0.01) or saline (p < 0.05).