Amygdala

• Glymphatic dysfunction in classical trigeminal neuralgia: DTI-ALPS index stratification from healthy controls to post-MVD
• Afferent and efferent fiber systems of the human amygdala: anatomical, pathophysiological, and clinical significance
• New finding for neuronal basis of the learned helplessness syndrome secondary to loudness: nonresistant rats have more damaged neurons in the amygdala than resistant rats
• Convergent large-scale network and local vulnerabilities underlie brain atrophy across Parkinson's disease stages: a worldwide ENIGMA study
• Feature-based encoding of face identity by single neurons in the human amygdala and hippocampus
• Mapping human brain topography to heart rhythms: an SEEG study
• Stellate ganglion block diminishes consolidation of conditioned fear memory in mice by inhibiting the locus coeruleus to the basolateral amygdala neural circuit
• Endoscopic transorbital amygdalohippocampectomy for the resection of an epileptogenic lesion

The amygdala is situated in the medial temporal lobe, on either side of the brain, near the hippocampus. It is part of the limbic system, a group of brain structures involved in emotions, memory, and motivation.

The amygdala is composed of several nuclei, each with its own functions. The main nuclei include:

Basolateral Nuclei (BL): Involved in the processing and integration of sensory information.

Central nucleus of the amygdala (CeA): Plays a key role in emotional responses, including the expression of fear.

Corticomedial Nuclei (CM): Associated with olfactory and visceral (internal organ) processing.

The amygdala is extensively connected to other brain regions, allowing it to receive and send information. Some of the key connections include:

Hippocampus: Involved in memory formation.

Thalamus: Relays sensory information to the amygdala.

Hypothalamus: Regulates physiological responses to emotions, such as the “fight or flight” response.

Prefrontal Cortex: Involved in the regulation of emotional responses and decision-making.

The amygdalae (singular: amygdala; /əˈmɪɡdələ/; also corpus amygdaloideum; Latin, from Greek ἀμυγδαλή, amygdalē, 'almond', 'tonsil', listed in the Gray's Anatomy textbook as the nucleus amygdalæ, (translation from Arabic al-lauzatani) are almond-shaped groups of nuclei located deep and medially within the temporal lobes of the brain in complex vertebrates, including humans. Shown in research to perform a primary role in the processing of memory, decision-making, and emotional reactions, the amygdalae are considered part of the limbic system.

In 1958, Niemeyer described a more selective approach to the hippocampus and amygdala through the middle temporal gyrus ¹⁾.

The human amygdala and hippocampus play important roles in face perception, but it remains unclear how task demands or evaluative contexts modulate neural face processing, especially at the single-neuron level in the human brain. In a study, Cao et al. comprehensively analyzed how task instruction modulates key aspects of face processing, including low-level facial features such as face shape and texture, social trait judgment of faces such as trustworthiness and dominance, as well as neural correlates of eye movement when viewing faces. This comprehensive survey of task modulation of face processing reveals both flexible and invariant neuronal processes in the human brain ²⁾.

Amygdala Dysfunction or abnormalities in the amygdala can lead to emotional and mood disorders, such as anxiety disorders, post-traumatic stress disorder (PTSD). Understanding the amygdala's functions and its interactions with other brain regions is critical in research and clinical applications related to emotional processing, stress management, and psychiatric disorders.