Connectivity-based parcellation of the amygdala and identification of its main white matter connections

Abstract

The amygdala plays a role in emotion, learning, and memory and has been implicated in behavioral disorders. Better understanding of the amygdala circuitry is crucial to develop new therapies for these disorders. We used data from 200 healthy-subjects from the human connectome project. Using probabilistic tractography, we created population statistical maps of amygdala connectivity to brain regions involved in limbic, associative, memory, and reward circuits. Based on the amygdala connectivity with these regions, we applied k-means clustering to parcellate the amygdala into three clusters. The resultant clusters were averaged across all subjects and the main white-matter pathways of the amygdala from each averaged cluster were generated. Amygdala parcellation into three clusters showed a medial-to-lateral pattern. The medial cluster corresponded with the centromedial and cortical nuclei, the basal cluster with the basal nuclei and the lateral cluster with the lateral nuclei. The connectivity analysis revealed different white-matter pathways consistent with the anatomy of the amygdala circuit. This in vivo connectivity-based parcellation of the amygdala delineates three clusters of the amygdala in a mediolateral pattern based on its connectivity with brain areas involved in cognition, memory, emotion, and reward. The human amygdala circuit presented in this work provides the first step for personalized amygdala circuit mapping for patients with behavioral disorders.

Neurotensin and Alcohol Use Disorders: Towards a Pharmacological Treatment

“…AMY contains several highly interconnecting nuclei (comprising the basolateral, cortical, central, and extended amygdala), projecting and receiving inputs from the PFC, NA, VTA, thalamus, and hypothalamus (Figure 7) [43,89]. Recent studies on in vivo mapping of the human AMY and neuroimaging studies provide new and applicable information that may help the setting of patient-directed modulatory therapies in brain behavioral alterations [90], including substance-abuse disorders [84].…”