Additionally, inadequate signaling in somatostatin-positive GABAergic interneurons in prefrontal microcircuits (established as one of the key substrates in MDD) can potentially produce attenuated pyramidal neuron output from the PFC and subsequent downstream regulation of threat and danger circuits (amygdala and bed nucleus of the stria terminalis) and sensory and motor processing in the thalamus, mimicking monoamine insufficiency in the brainstem [145, 146]. Here, SST is linked to major depressive disorder.