Fig. 2

SC PV⁺ neurons are essential for visually triggered dimorphic defensive behaviors. a Left, Micrographs showing immunostaining of PV vs. glutamate (top) or PV vs. GABA (bottom) in SuG layer of the SC. Arrows indicate PV⁺ neurons. Right, quantitative analyses indicating most SC PV⁺ neurons in SuG and Op layers are glutamate⁺ and GABA⁻. Scale bars, 30 μm (top) and 35 μm (bottom). b Coronal SC section (top) and micrographs (bottom) of PV-ires-Cre mice injected with AAV-DIO-EGFP-2A-TeNT, showing expression of EGFP in SC neurons positive for PV, glutamate but negative for GABA. Scale bars, 0.5 mm (top) and 30 μm (bottom). c Coronal SC section (left) and micrograph (right) showing SC PV⁺ neurons co-labeled by EGFP and ChR2-mCherry after injection of AAV-DIO-EGFP-2A-TeNT and AAV-DIO-ChR2-mCherry mixture into the SC of PV-ires-Cre mice. Scale bars, 0.3 mm (left) and 20 μm (right). d Schematic diagram of slice physiology (left) and example traces (right) showing neurotransmitter release from SC PV⁺ neurons was blocked by TeNT. e Input−output curves of light-evoked PSCs recorded from ChR2-negative neurons. f, g Distribution of speed during vs. before (f) and after vs. before (g) visual stimuli of mice with active (Ctrl) or inactive (TeNT) SC PV⁺ neurons. h Distribution of LSI_{during stimuli} and LSI_{after stimuli} of mice with active (Ctrl) or inactive (TeNT) SC PV⁺ neurons. i Heat-maps of speed time course of example mice with active (Ctrl) or inactive (TeNT) SC PV⁺ neurons. j, k Effects of synaptic inactivation of SC PV⁺ neurons on locomotion speed of mice with Type I (j) and Type II (k) defensive behavioral patterns. For single-channel micrographs (b, c), see Supplementary Fig. 3. Data in (e, j, k) are means ± SEM (error bars). Numbers of cells or mice are indicated in the graphs. Statistical analysis was Student’s t test (***P < 0.001; n.s. P > 0.1) and one-way ANOVA