Amygdala pathology in Parkinson's disease.

The amygdala undergoes severe pathological changes during the course of Parkinson's disease (PD). Lewy bodies and Lewy neurites are distributed in a specific manner throughout the nuclear complex. The lesional pattern displays only minor interindividual variation. The most prominent changes occur in the accessory cortical and central nuclei. The cortical, accessory basal and granular nuclei show less severe alterations, while the basal and lateral nuclei, as well as the intercalated cell masses, generally remain uninvolved. The amygdala receives a broad range of afferents, allowing integration of exteroceptive information with interoceptive data. It generates major projections to the isocortex (the prefrontal cortex in particular), limbic system (hippocampus and entorhinal region) and centers regulating endocrine and autonomic functions. The specific lesional pattern seen in PD destroys part of the nuclear gray matter and its connections and, thus, may likely contribute to the development of behavioral changes and autonomic dysfunctions.