Fig. 3: The SuM-DG circuit mediates response to alertness-related inputs.
A Schematic and fluorescence images showing the viral tracing strategy used to label projections from SuM to DG. B Timeline of the experimental procedure and bar graph depicting the percentage of SuM neurons co-expressing c-Fos and GFP. C Representative fluorescence images showing co-localization of GFP (green) and c-Fos (red) in SuM neurons. D Schematic showing in vivo electrophysiological recording and optogenetic activation used to depict functional connections of SuM-DG. E DG-projected SuM Neuronal spiking counts evoked by a transient optogenetic activation at SuM-DG neuronal fibers. F Above, schematic of the viral strategy employed for optogenetic manipulation of SuM neurons. Below, representative fluorescent images showing the AAV injection and expression at bilateral SuM. G Above, timeline of looming tests with optogenetic manipulation. Below, reaction times of animals in response to looming stimuli across 30 trials and under sham light stimulation in 11th to 18th trials. H Reaction times of animals in response to looming stimuli across 30 trials and under blue (activation) or yellow (inhibition) optogenetic manipulations. I Schematic of novel environment exposure experiment with sham, blue, and yellow optogenetic manipulations in the second phase. J Bar graph showing latency to sniff novel objects under sham, blue, and yellow light conditions. K Bar graphs illustrating time withdraw from object before, during, and after the optogenetic activation and inhibition.
