Table 2.

Summary of electrophysiology data reflecting the ν of a neuronal ensemble

	Baseline ν, Hz	Stimulation ν, Hz	Δν/ν
Condition I	9.5  ± 2.4†	12.3  ± 4.0†	0.29  ± 0.13
Condition II	6.7  ± 1.8‡	13.7  ± 3.2‡	1.04  ± 0.32

Data (mean ± SD) averaged across all rats (Fig. 3) from all extracellular recordings in the contralateral side, where ≈60% of the spiking data showd an increase in ν, ≈10% of the spiking data showed a decrease in ν, and ≈30% of the spiking data showed no change in ν (Fig. 2). Student's t test with two samples assuming unequal variances (one-tail) was used for comparing mean values of ν in baseline and stimulation periods in both conditions (n = 36). Spike analysis of extracellular data from 33 electrode penetrations generated two recognizable neurons each (i.e., 33 × 2 = 66). Since data from three penetrations generated either one (two data sets) or three (on data set) recognizable neurons, the spiking frequency from each data set was normalized to reflect two neurons (i.e., 3 × 2 = 6). Therefore, the ensemble represented a total of 72 recognizable neurons (i.e., 36 × 2). The correlation coefficients (22) of the stimulation-induced changes in ν for different experimental runs from all rats were high (0.7–0.9; data not shown) for both conditions. Spiking activity in the ipsilateral side did not show any significant changes during stimulation (data not shown).

^*The baseline values for ν in conditions I and II were significantly different (P < 0.01), where baseline in condition II was lowered by 0.29 ± 0.11 from baseline in condition I. The stimulation values for ν in conditions I and II were not significantly different (P > 0.25). The incremental changes in ν from respective baselines (Δν/ν) were also significantly different (P < 0.05).

^† Significantly different baseline and stimulation values for ν in condition I (P < 0.05).

^‡Condition II (P < 0.01).