Infralimbic cortex explained

Infralimbic cortex
Latin:	Cortex infralimbicus

The infralimbic cortex (IL) is a cortical region in the ventromedial prefrontal cortex which is important in tonic inhibition of subcortical structures and emotional responses, such as fear.^[1]

Connectivity

Primates

GABAergic neurons within the amygdala, known as intercalated (ITC) cells, receive a strong projection from the IL medial prefrontal cortex (mPFC) in primates.^[2] ITC cells are thought to play a role as the 'off switch' for the amygdala, inhibiting the amygdala's central nucleus output neurons and its basolateral nucleus neurons.^[3] Further, it has been shown that electrical stimulation of IL reduces conditioned fear and strengthens extinction memory, explaining cortical control over extinction processes, one of the simplest forms of emotional regulation.^[3]

Rodents

Amygdala ITC cells receive strong projection from the IL mPFC in rodents as well.^[4]

See also

• Medial prefrontal cortex
• Intercalated cells of the amygdala

References

1. "Microstimulation reveals opposing influences of prelimbic and infralimbic cortex on the expression of conditioned fear." Learn. Mem., Vol. 13, No. 6. (1 November 2006), pp. 728-733. Ivan Vidal-Gonzalez, Benjamin Vidal-Gonzalez, Scott L Rauch, Gregory J Quirk.
2. Chiba et al., 2001; Ghashghaei and Barbas, 2002.
3. Quirk, G.J. & Mueller, D. (2007). Neural mechanisms of extinction learning and retrieval. Neuropsychopharmacology Reviews, 1-17.
4. McDonald et al., 1996.