The amygdala Functional organization and involvement in neurologic disorders

The amygdala consists of a group of heterogeneous nuclei located in the medial portion of the temporal lobe and is involved in multimodal information processing important for emotional recognition and behavior. Its complex structure includes basolateral, centromedial, and cortical nuclear complexes that have extensive connections with several cortical and subcortical structures. Pioneering studies on rodents established that the amygdala is critical for theacquisition and expression of conditioned (Pavlovian) fear responses and yielded important insights into its intrinsic connectivity and synaptic plasticity. More recent studies indicate that neurons of the amygdala differentially respond to the valence (positive or negative affective significance) of stimuli and that the amygdala, via its interconnections with the prefrontal cortex, is necessary for representation of value that is required for reward-based decision-making. Functional neuroimaging and electrophysiologic and psychometric approaches both in healthy persons and in patients with selective damage of the amygdala in genetic disorders such as lipoid proteinosis (Urbach-Wiethe disease) support its role in many aspects of emotional processing, including recognition of emotional expression in faces. The amygdala is affected in several neurologic disorders and psychiatric disorders including Alzheimer disease (AD), temporal lobe epilepsy (TLE), and anxiety, and depression. The anatomy and physiology of the amygdala and its role in emotion and behavior has been reviewed.

Neuurology 2014