Figure 3.

A: Peri-movement activity of exemplar GPi single-units sampled pre- (left) and post-MPTP (right). Mean SDFs and raster representations of trial-by-trial spike trains are aligned across trials to the time of movement onset (time zero). Vertical black dashed line and gray rectangle indicate the median and IQR of the times of go-cue onset (left) and the end of movement (right) relative to movement onset. Sloped red lines: the unit’s mean baseline trendline ± confidence interval. Vertical green line: time of onset of mean response. For raster diagrams, single trial spike trains are sorted according RT, shortest at top. For each trial, colored circles indicate times of go-cue onset (cyan) and target contact (olive).

B: Peri-movement SDFs of all single-units studied, sorted according to response type and response onset latency relative to movement onset (earliest onset at the top for each response category). Left and right panels show data from pre- and post-MPTP periods, respectively. SDFs were z-scored relative to the mean baseline activity prior to go-cue onset and displayed on a color scale (inset). C: Overall proportions of perimovement responses classified into the four response types differed between pre- and post-MPTP conditions (green and magenta, respectively; p<0.01, chi-square test). The proportion of polyphasic (−/+) responses decreased post-MPTP as compared to the pre-MPTP population (** p<0.01, standardized residual analysis). D: Mean population-averaged SDFs constructed separately for each response type and pre- and post-MPTP collection periods (green and magenta, respectively). Shaded areas: ±SEM.