Figure 5.

Direct and Indirect Pathway MSNs Respond Differently to Bilateral Whisker Deflection

(A) Examples of immunohistochemistry for identifying D1 and putative D2 MSNs. From left to right; Neurons filled with neurobiotin, D1 receptor expression, and merged images of neurobiotin (red) and D1 receptor expression (green). Yellow narrows indicate the corresponding neuron position in the respective images.

(B) A schematic of the whisker stimulation procedure.

(C) Input resistance for D1 and D2 MSNs calculated from voltage responses to hyperpolarizing and depolarizing current steps during down states.

(D) Waveform averages of responses to whisker deflections in D1 MSN (left) and D2 MSN (right).

(E, F, H, and I) Averages comparing the responses for contralateral (blue), ipsilateral (green), and bilateral stimulation (red) in D1 and D2 MSNs during down states (D1 MSN n = 15; D2 MSN n = 13). Average onset delays (E), peak delays (F), amplitudes (H), and slopes (I).

(G) Peak delays for all D1 and D2 subpopulations in response to contralateral and ipsilateral stimuli. Inset shows the time difference between the peak of the ipsilateral and contralateral responses for D1 and D2 MSNs.

(J) A schematic of the contralateral whisker and visual stimulation protocol.

(K) Examples of average responses to whisker and visual stimulation in D1 (left) and D2 (right) MSNs.

Error bars represent the SEM and asterisks ^∗, ^∗∗, and ^∗∗∗ represent p values smaller than 0.05, 0.01, and 0.001, respectively.