Figure 3. LTP evoked by high frequency afferent stimulation is not observed in DA neurons from NR1^DATCre mice.

(A) Photomicrograph of a recorded VTA neuron. The left panel shows a biocytin labeled neuron, the middle panel shows TH immunohistochemistry in the same brain slice, and the right panel shows a merged image demonstrating the overlap of biocytin and TH staining. Scale bar  = 40 µm. (B) Mean time course of EPSPs before and after LTP initiation (arrow) in both WT and NR1-KO cells. Scale bars are 5 mV and 25 ms. The spike timing protocol did not lead to LTP in any of the KO cells tested (n = 23, gray circles). However, all 10 WT DA cells demonstrated LTP (black circles).