Figure 3
Lack of Rhes does not affect D2R-mediated responses in the dopaminergic neurons and cocaine-induced dopamine release in the striatum. (A–C) Representative confocal images of midbrain coronal section processed for combined in situ hybridization and immunohistochemical labeling showing coexpression of Rhes mRNA and TH protein in midbrain dopaminergic neurons. Scale bar: 500 μm. (D–F) Quantitative reverse transcription-PCR to evaluate Rhes mRNA expression in DStr (n = 6) and midbrain (n = 6) from WT mouse samples. ***p < 0.0001, compared to DStr group, Unpaired t test. (E,F) Analysis of 32-kDa (E) and 47-kDa (F) Rhes protein abundance in DStr and midbrain (n = 3) from wild-type mouse lysates. Unpaired t test, p < 0.001 (E), p < 0.0001 (F). ***p < 0.0001, compared to DStr group. (G) Infrared videomicroscopy image of a midbrain dopamine neuron selected for patch-clamp recordings. (H) Representative traces (upper panel) of quinpirole (1 µM, 3 min)-induced currents in midbrain dopamine neurons from brain slices of Rhes KO and WT littermates (n = 7) and histogram of mean amplitudes of quinpirole-activated currents. (I) Normalized reduction of the stimulus-evoked DA release by bath perfusion of quinpirole 100 nM (10 min) in WT and KO (n = 4) male mice. (J,K) CPA recordings showing the effect of cocaine in striatum on evoked dopamine in WT and KO (n = 3) male mice. (J) Effect of cocaine at the different concentrations [nM] on dopamine efflux, represented as normalized values of increased amplitude. (K) Effect of cocaine on the uptake rate, represented as normalized values of decay slope/amplitude. All values are expressed as mean ± SEM. Genotypes and treatments are as indicated.
