Figure 3. Optogenetic activation of hypothalamic Foxb1+ terminals in the rostral dlPAG induces freezing-like behavior.

(a) A representative example of track visualizations with underlying density maps for a ChR2-expressing Foxb1-Cre mouse belonging to the ‘OnTarget_antPAG’ group during 3 min of baseline (left) and 3 min of optogenetic stimulation (right). Note that the mouse remained immobile for the entire duration of the stimulation period. The color coding scales are not fixed between the two conditions. Open field arena dimensions are 40x40cm. Track visualization with underlying density maps for all other mice can be found in Supplementary file 3. (b) A representative example of a zone visit diagram taken from the same recording as the track visualizations in (a). Note, that the zone transitions stop completely after the onset of optogenetic stimulation. Zone visit diagrams for all other mice can be found in Supplementary file 4. (c) A visual representation of the arena partitioning into the different zones (i.e. arena, periphery, center, and four corners). (d-h) Comparison of multiple parameters extracted from the open field experiments. Optogenetic activation of parvafox^Foxb1 terminals in the PAG reduces distance moved (d), speed.moving (e), and time in center (h), while time spent immobile (f) and time in periphery (g) increases. Optogenetic silencing of parvafox^Foxb1 terminals in the PAG induces opposing effects.