User:Kunal Kambo Puri/Amygdalofugal pathway

The amygdalofugal pathway is one of the three major efferent pathways of the amygdala. It leads from the basolateral and central nuclei of the amygdala.

This pathway is particularly important for associative learning.

Basolateral Nucleus
The basolateral nucleus cooperates with the central nucleus in persistent fear responses. It influences regions of the brainstem through the central nucleus via the amygdalofugal pathway and the stria terminalis.

Oxytocin has been visualized in the basolateral nuclei.

Central Nucleus
The central nucleus can be thought of as the exit of the amygdaloid bodies through which the bodily responses that are associated with fear leave the amygdala.

The amygdalofugal pathway connects the central nucleus of the amygdala to the brainstem. The stria terminalis does so also but in a longer, less direct route. These connections collectively are involved with emotional responses. The brainstem regions that the central nucleus connects to are responsible for controlling “expression of innate behaviors and associated physiological responses.” The central nucleus also has three subnuclei: lateral, capsular, and medial. It is the medial subnucleus that forms connections with “response control regions.” Most of the projection neurons in the central nucleus are inhibitory.

The nucleus basalis also connects the central nucleus of the amygdala to the cortex through cholinergic projections that “are thought to arouse the cortex.”

Lesion experiments show that the central nucleus of the amygdala connects with the startle circuit via the caudal part of the amygdalofugal pathway. This is the part of the pathway that projects directly to the parts of the pons, medulla, and perhaps the spinal cord.

Conscious perception of emotion involves output from the central nucleus of the amygdala as well as its connections through the amygdalofugal pathway to the anterior cingulate cortex, orbitofrontal cortex, and prefrontal cortex. .

Nucleus Accumbens
The connections of the amygdalofugal pathway to the nucleus accumbens plays a role in the perception of a stimulus as either gratifying or aversive.

Anterior Cingulate Cortex
One reason that the amygdalofugal pathway is important is because it links motivations to responses. The anterior cingulate cortex in particular is considered the link between emotions and decisions.

Hypothalamus and Septal Nucleus
The stria terminalis, not the amygdalofugal pathway, is the main connection between the amygdala and the hypothalamus.

The hypothalamus is a highly important structure that is involved with the regulation of bodily functions. These include endocrine, autonomic, and behavioral functions. It produces a wide variety of hormones. These control body temperature, hunger, moods, sex drive, sleep, thirst, and release of other hormones. There are dozens of peptides within the hypothalamus that have been discovered in recent years. The hypothalamus also influences daily physiologic cycles and plays a role in regulating emotional responses. Many of these functions can be described as homeostatic. It is the most ventral part of the diencephalon and contains three regions: the supraoptic region, the tuberal region, and the mammillary region.

Other Research
In one study, prescription opioid patients were found to have decreased anisotropy in the amygdalofugal pathway.