Fig. 2.

Neural circuits for visual threat processing and response across species, in Drosophila (A), zebrafish (B), and mouse C). A Core pathways for escape (left) and freezing (right) in response to visual threats in Drosophila. Lo, lobula; Lp, lobula plate; Me, medulla. Dashed line for DNp09: possible connection. The dashed line on the left indicates a non-GF pathway for long take-off. Black arrows in the Lp: the preferred motion directions of T5 neurons. B Core escape circuit in zebrafish. Light brown shaded region: thalamus. SINs, superficial inhibitory interneurons; PVNs, periventricular neurons; M-cell, hindbrain Mauthner cell. The dashed line indicates that non-M cells participate in slow escape. Other colored lines indicate modulation of the tectum and M cells. C Core pathways for escape (red) and freezing (blue) in response to visual threats in the mouse. The four modulatory systems are involved in visual threat-evoked innate defensive behaviors, but the scope of their effects and their target brain regions are not fully understood yet. Red/blue: circuit components of the escape/freezing pathway, respectively; purple: participants in both pathways; other colors: modulation of the SC; dotted lines: other sensory inputs. sSC superficial superior colliculus, m/dSC intermediate/deep superior colliculus, LP lateral posterior nucleus, PBG parabigeminal nucleus, Amg amygdala, Hypo hypothalamus, PAG periaqueductal grey, LPGi lateral paragigantocellular nucleus.