Table 2.
Firing rates and synchronization of neurons in the arm area of MI in the normal and MPTP states
| Monkey S | Monkey Z | |||
|---|---|---|---|---|
| Normal | MPTP2-a | Normal | MPTP2-a | |
| A. Firing rates (spikes per second) | ||||
| n(cells) | 75 | 145 | 62 | 106 |
| During “active periods”2-b (mean ± SEM) | 5.9 ± 0.8 | 8.5 ± 1.3 | ||
| During “immobile periods”2-c(mean ± SEM) | 3.8 ± 0.5 | 4.3 ± 0.5 | 5.0 ± 0.8 | 4.5 ± 0.5 |
| B. Firing patterns2-d | ||||
| n(cells) | 65 | 124 | 51 | 104 |
| % (n) peaked autocorrelograms2-e | 100% (65) | 96% (119) | 100% (51) | 92% (96)* |
| Auto-association index (%)2-c,2-f(mean ± SEM) | 28 ± 3 | 42 ± 4* | 12 ± 2 | 28 ± 32-160 |
| C. Synchronization2-d | ||||
| n (pairs) | 128 | 435 | 136 | 372 |
| % (n) synchronized2-e | 52% (67) | 57% (246) | 29% (40) | 36% (135) |
| Association index (%)2-c,2-f (mean ± SEM) | 34 ± 2 | 50 ± 22-165 | 36 ± 3 | 50 ± 32-160 |
| % (n) of strongly synchronized pairs2-f,2-g | 12% (8) | 43% (106)2-165 | 10% (4) | 41% (56)2-165 |
All tests compare between the normal immobile and the MPTP states. p values:
<0.05;
F2-160: <0.01;
F2-165: <0.001.
Mean firing rates were significantly higher in the active periods relative to the immobile ones in the normal state (p < 0.001; one-sided pairedt test).
Two-sided two-sample ttest.
The threshold to determine whether the autocorrelograms or cross-correlograms were significantly peaked was set to the upper confidence level of the estimated correlogram. Shifting the threshold did not qualitatively change the results concerning the differences between the normal immobile and MPTP states vis-à-vis the percentage of peaked autocorrelograms and cross-correlograms or the distribution of their indices.
Two-sided Fisher exact test/χ2 test.
Only pairs with significant peaks (AI or AAI larger than 0%) were included.
Pairs with AI >50% were considered strongly synchronized.