Figure 1.

Decreased intrinsic excitability of PTNs in the L5b of M1 following the loss of midbrain DA neurons. A, B, Representative graphs showing the injection site of red Retrobeads in the pontine nuclei (A) and a retrogradely labeled PTN in L5b of M1 (B). C, D, Representative spike trains of PTNs evoked by somatic current injections from controls and 6-OHDA mice (C) and the frequency-current relationship of the PTNs from controls and 6-OHDA mice (D). E–H, Summarized results showing an increased rheobase (E), a reduced gain of spike-current curve (F), a decreased firing frequency in response to maximal current injections (i.e., 720 pA; G), and an enhanced spike adaptation (H) in PTNs from 6-OHDA mice relative to those from controls; *p < 0.05, MWU.