Figure 4.

Firing Properties of Identified GPe Neurons in Awake Mice at Rest

(A and B) Typical single-unit activity (top), extended raster plots (bottom), autocorrelograms (right), and expression profiles (far left; scale bars, 20 μm) of a prototypic neuron (A) and an arkypallidal neuron (B). Individual neurons were juxtacellularly labeled with Neurobiotin (Nb) after recording; prototypic neurons expressed Nkx2-1 (but not FoxP2), whereas arkypallidal neurons expressed FoxP2 (but not Nkx2-1).

(C) Mean firing rate of prototypic neurons was significantly higher than that of arkypallidal neurons (48.3 ± 3.4 versus 9.8 ± 2.3 spikes/s; n = 44 and 13 neurons, respectively).

(D) Firing of prototypic neurons was more regular than that of arkypallidal neurons (CV2 of 0.38 ± 0.02 versus 1.11 ± 0.07).

(E) Prototypic neurons fired fewer spikes within bursts as compared to arkypallidal neurons (16.9% ± 1.8% versus 57.3% ± 3.7% of spikes; n = 44 and 12 neurons, respectively).

(F) Schematic parasagittal sections (D, dorsal; C, caudal) denoting the locations within the GPe of all recorded and identified neurons. Mediolateral (ML) distance from Bregma is shown on right. Scale bar, 1 mm.

Data are represented as mean ± SEM; ^∗∗∗p < 0.001.