Fig. 6: SC–SNc pathway is selectively required for appetitive locomotion during predatory hunting.
From: The tectonigral pathway regulates appetitive locomotion in predatory hunting in mice
a Schematic diagram showing the dual-AAV strategy to selectively inactivate the SNc-projecting SC neurons with TeNT. b An example coronal brain section showing EGFP+ SNc-projecting SC neurons distributed in the intermediate layer (In) and deep layer (Dp) of SC. Inset, merged and single-channel micrographs showing SNc-projecting SC neurons were dually labeled by mCherry and EGFP. This experiment was repeated independently in 12 mice with similar results. c Schematic diagram showing predatory hunting paradigm in an arena. d, e Behavioral ethograms showing the time courses of locomotion speed (top) and jaw attacks (bottom) during predatory hunting of example mice either without (d Ctrl) or with (e TeNT) synaptic inactivation of SNc-projecting SC neurons. The shaded areas (orange) indicated the approach episodes in predatory hunting. f–j Quantitative analyses of time to capture (f), latency to attack (g), frequency of attack (h), speed of approach (i), and frequency of approach (j) during predatory hunting in mice without (Ctrl) and with (TeNT) synaptic inactivation of SNc-projecting SC neurons. k Time courses of locomotion speed before, during, and after looming visual stimuli in mice without (Ctrl) and with (TeNT) synaptic inactivation of SNc-projecting SC neurons. l–n Quantitative analyses of peak locomotion speed during stimuli (l), average locomotion speed after stimuli (m), and average locomotion speed before stimuli (n) of mice without (Ctrl) and with (TeNT) synaptic inactivation of SNc-projecting SC neurons. Number of mice was indicated in the graphs (f–n). Data in f–n are means ± SEM (error bars). Statistical analyses in f–j, l–n were performed by one-sided Student’s t-tests (n.s.P > 0.1; *P < 0.05; **P < 0.01). Scale bars are indicated in the graphs.
