The intercalated cells of the amygdala (ITC or ICC) are a group of
GABAergic
In molecular biology and physiology, something is GABAergic or GABAnergic if it pertains to or affects the neurotransmitter GABA. For example, a synapse is GABAergic if it uses GABA as its neurotransmitter, and a GABAergic neuron produces GABA. A ...
neurons situated between the basolateral and central nuclei of the
amygdala
The amygdala (; plural: amygdalae or amygdalas; also '; Latin from Greek, , ', 'almond', 'tonsil') is one of two almond-shaped clusters of nuclei located deep and medially within the temporal lobes of the brain's cerebrum in complex ver ...
that play a significant role in inhibitory control over the amygdala.
They play important regulatory roles in amygdala-dependent emotional processing, and their dysfunction has been shown to impair fear extinction, fear generalization, and social behavior. In rodents, ITCs are organized into distinct clusters that wrap the basolateral amygdala (BLA).
Each cluster is unique in connectivity, intrinsic properties, and function.
Function
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.
The ITC clusters work together to activate either "fear promoting" or "fear extinction" pathways within the amygdala.
Some researchers speculate that ITC cells could serve as a substrate for the expression and storage of extinction memory via their extensive local inhibition within the amygdala.
Connectivity
ITCs have complex connectivity patterns, with projections from a variety of cortical and thalamic regions. In the rodent model, each ITC cluster has its own connection and projection patterns. There also appears to be extensive inter-cluster and intra-cluster connectivity which refines signals and allows for cluster communication.
The ITC dorsomedial cluster (ITCdm) and ITC ventromedial cluster (ITCvm) innervate specific neurons within the basal amygdala (BA), which project to the medial prefrontal cortex (mPFC). The opposing action of these two clusters has been shown to modulate fear vs extinction states.
There is also some evidence that ITCs receive some inputs from the mPFC and was originally thought that the infralimbic prefrontal cortex directly innervates the ITCs.
However, recent optogenetic studies have shown that in the rodent model, ITCs do not receive direct inputs from the IL prefrontal cortex.
See also
*
Amygdala
The amygdala (; plural: amygdalae or amygdalas; also '; Latin from Greek, , ', 'almond', 'tonsil') is one of two almond-shaped clusters of nuclei located deep and medially within the temporal lobes of the brain's cerebrum in complex ver ...
*
Basolateral Amygdala
The basolateral amygdala, or basolateral complex, consists of the lateral, basal and accessory-basal nuclei of the amygdala. The lateral nuclei receives the majority of sensory information, which arrives directly from the temporal lobe structures, ...
*
Medial prefrontal cortex
In mammalian brain anatomy, the prefrontal cortex (PFC) covers the front part of the frontal lobe of the cerebral cortex. The PFC contains the Brodmann areas BA8, BA9, BA10, BA11, BA12, BA13, BA14, BA24, BA25, BA32, BA44, BA45, BA4 ...
References
{{DEFAULTSORT:Intercalated Cells Of The Amygdala
Amygdala