The left amygdala is a paired subcortical structure located in the medial temporal lobe, forming part of the limbic system and closely associated with the hippocampus and parahippocampal regions. Composed of multiple nuclei (including basolateral, centromedial, and cortical groups), it is critically involved in emotional processing, fear conditioning, salience detection, and modulation of autonomic and endocrine responses through its connections with the hypothalamus and brainstem. The left amygdala is also implicated in memory consolidation for emotionally salient events, social cognition, and affective components of decision-making, with hemispheric lateralization studies suggesting partially distinct contributions to language-related emotional processing and conscious appraisal of affect. A detailed overview of the amygdala can be found at Amygdala.
The left amygdala, as defined in the AAL2 atlas, has been repeatedly implicated in imaging–genetics and GWAS studies examining subcortical brain volumes and functional variation, with several robust genetic associations identified. Large-scale GWAS (e.g., ENIGMA, UK Biobank) have shown that common variants near genes involved in neurodevelopment, synaptic signaling, and cellular growth—such as SLC39A8, MAPT, TESC, APOE, and DRAM1—contribute to inter-individual differences in amygdala volume, including asymmetric effects on the left side. Polygenic risk scores for major depressive disorder, anxiety disorders, bipolar disorder, schizophrenia, and autism spectrum disorder have been linked to structural and functional alterations in the left amygdala, consistent with its role in threat processing and emotional regulation. Specific loci associated with psychiatric risk (for example, in CACNA1C, ZNF804A, and genes within the major histocompatibility complex) have been related to altered left amygdala activation in emotion-processing tasks, while variants in serotonin transporter (SLC6A4) and BDNF (notably Val66Met) have been associated with differences in left amygdala reactivity and connectivity in response to emotional stimuli, as well as with susceptibility to stress-related and mood disorders. Collectively, these findings support a polygenic architecture in which multiple common and some rare variants influence left amygdala structure and function, thereby modulating risk for affective, anxiety, psychotic, and stress-related traits.
Overview generated by GPT-4o (2026).
Region ID: 4201
Hemisphere: left
Atlas: AAL2
Full Quality Version: Download MP4
Full Quality Version: Download MP4
Full Quality Version: Download MP4
Full Quality Version: Download MP4
Wali Sidiqyar*, Gaurav Rudravaram*, Elyssa M. McMaster, Trent M. Schwartz, Adam M. Saunders, Kurt G. Schilling, Bennett A. Landman "Introducing SPINS: A Shared Public Visualization Library of Neuroanatomical Structures." Medical Imaging with Deep Learning- short paper
This resource is licensed under CC0 1.0 Universal (Public Domain).