Fig. 6
Optogenetic dissection of the DR/PAG → CeA pathway. a Schematic showing retrograde labeling of central amygdala (CeA) projecting neurons in the dorsal raphe/periaquecductal gray (DR/PAG) using VGlut2-Cre mice. Inset shows sample injection site of retrobeads (white) in the CeA (scale bar 0.5 mm). b Analysis of colocalization between eYFP-positive (i.e., eYFP+, VGlut2 expressing; green) and TH-immunopositive (i.e., TH+, putatively dopaminergic; red) CeA-projecting (i.e., beads+, white) cell populations in the DR/PAG. Left: Confocal image showing overview of DR/PAG in VGlut2-Cre mice (scale bars 0.5 mm). Middle: Higher magnification image. Right: Slice charts showing percentage of beads+ and eYFP+ cells that co-express TH (eYFP+/beads+/TH+, blue) or lack expression of TH (beads+/eYFP+/TH−, orange) in the DR/PAG (scale bars 50 µm). c Schematic of experimental design to analyze functional connectivity of DR/PAG inputs to CeA neurons using DAT-Cre, TH-Cre and VGlut2-Cre mice. d Sample traces from whole-cell recordings at −70 mV showing EPSCs generated by light stimulation of DR/PAGVGLUT2 inputs to CeA neurons (red trace: sample of mean EPSC after CNQX application; scale bars: 20 pA/10 ms). Schematics shows localization of the recorded neurons in the CeA that responded (blue) and did not respond (gray) to light stimulation. Pie chart shows percentage of responders (blue) and non-responders (gray). Bar graph showing mean EPSC amplitudes for the cells that responded to light stimulation before (blue) and after (red) bath application of 10 μM CNQX (paired t-test, t(5) = 3.835 p = 0.0122, n = 6 cells; *p < 0.05; error bars represent SEM). e, f Same as in d, but experiments were performed in TH-Cre (e) and DAT-Cre (f) mice. Data provided as a Source Data file
