<P> The regions described as amygdala nuclei encompass several structures with distinct connectional and functional characteristics in humans and other animals . Among these nuclei are the basolateral complex, the cortical nucleus, the medial nucleus, the central nucleus, and the intercalated cell clusters . The basolateral complex can be further subdivided into the lateral, the basal, and the accessory basal nuclei . </P> <P> Anatomically, the amygdala, and more particularly its central and medial nuclei, have sometimes been classified as a part of the basal ganglia . </P> <P> There are functional differences between the right and left amygdala . In one study, electrical stimulations of the right amygdala induced negative emotions, especially fear and sadness . In contrast, stimulation of the left amygdala was able to induce either pleasant (happiness) or unpleasant (fear, anxiety, sadness) emotions . Other evidence suggests that the left amygdala plays a role in the brain's reward system . </P> <P> Each side holds a specific function in how we perceive and process emotion . The right and left portions of the amygdala have independent memory systems, but work together to store, encode, and interpret emotion . </P>

An over stimulated amygdala could result in what kind of behaviors