Brain region of tonic inhibition of fear
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]
Structure
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[clarification needed], explaining cortical control over extinction processes,[clarification needed] 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
References
- ^ "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.
- ^ Chiba et al., 2001; Ghashghaei and Barbas, 2002.
- ^ a b Quirk, G.J. & Mueller, D. (2007). Neural mechanisms of extinction learning and retrieval. Neuropsychopharmacology Reviews, 1-17.
- ^ McDonald et al., 1996.
Anatomy of the cerebral cortex of the human brain
Frontal lobe | Superolateral | Prefrontal | - Superior frontal gyrus
- Middle frontal gyrus
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Precentral | |
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Medial/inferior | |
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Both | |
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Parietal lobe | Superolateral | |
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Medial/inferior | |
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Both | |
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Occipital lobe | Superolateral | |
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Medial/inferior | |
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Temporal lobe | Superolateral | |
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Medial/inferior | |
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Interlobar sulci/fissures | Superolateral | |
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Medial/inferior | |
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Limbic lobe | |
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Insular cortex | |
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General | |
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Some categorizations are approximations, and some Brodmann areas span gyri. |