“…First, neuronal activation in the PAG has been observed upon exposure to a wide variety of threats, including live predator or predator odor (Cezario et al 2008), aggressive conspecifics (Motta et al 2009), loud ultrasound stimuli (Mongeau et al 2003), and electrical footshock (Johansen et al 2010). Second, impairment of PAG function diminishes the expression of defensive behaviors including freezing, risk assessment, flight, analgesia, and autonomical arousal (Hunsperger et al 1963, Schenberg et al 2014Sukikara et al 2006;Silva et al 2013). Third, stimulation of the PAG is sufficient to induce defensive responses of various types, including freezing, escape, and jumping (Bandler and Shipley 1994;Schenberg et al 2014).…”