Fig. 2. Schematic representation of the connections between midbrain tectum and amygdala, either directly or through the mediodorsal thalamus.

Dysfunctional dPAG-amygdala circuitry fed with all sorts of aversive stimuli that arrive at the midbrain tectum in PTSD disrupts the normal functioning of other prosencephalic centers such as the prefrontal cortex and the hippocampus, with which the amygdala has critical neural connections. SC: superior colliculus. dPAG: dorsal periaqueductal gray