What is the Amygdala?
The amygdala, so named because it resembles an almond, is a set of nuclei in the brain located closely to each other and therefore grouped under the same name. Among the most prominent are the basolateral complex, the centromedial nucleus, and the cortical nucleus. The amygdala is part of the limbic system, responsible for regulating the emotions. The amygdala is most commonly associated with the emotions of fear and anxiety, and its size is positively correlated to the level of aggression in a given species. It is also associated with the emotion of pleasure, though mainly in a negative sense, i.e., the pleasure sometimes inherent in aggression. There are two amygdalas, symmetrically arranged near the center of the brain, just above the hypothalamus. They are each about one inch in length. The amygdala has received much attention in recent decades, and has been the focus of many research projects. The amygdala plays a key part in what has been called the “general-purpose defense respo
`Amygdala’ and `amygdalar complex’ are terms that now refer to a highly differentiated region near the temporal pole of the mammalian cerebral hemisphere. Cell groups within it appear to be differentiated parts of the traditional cortex, the claustrum, or the striatum, and these parts belong to four obvious functional systems accessory olfactory, main olfactory, autonomic and frontotemporal cortical. In rats, the central nucleus is a specialized autonomic-projecting motor region of the striatum, whereas the lateral and anterior basolateral nuclei together are a ventromedial extension of the claustrum for major regions of the temporal and frontal lobes. The rest of the amygdala forms association parts of the olfactory system (accessory and main), with cortical, claustral and striatal parts. Terms such as `amygdala’ and `lenticular nucleus’ combine cell groups arbitrarily rather than according to the structural and functional units to which they now seem to belong. The amygdala is neithe
