Anterior Amygdaloid Area
abbreviation: AA
Abbreviation
AA
Species
Rat
Description of part
...is a transition region inserted between the amygdala and the rostral basal forebrain structures. It lacks the stratified arrangement seen in other superficial amygdaloid nuclei, and appears as a diffuse mass of lightly stained cells of different sizes and shapes. but with a predominance of medium sized elements with oval or slender triangular cell bodies. Just caudal to the olfactory tubercle, AA reaches the brain surface and persists in this superficial position until LOT appears. Medial to the LOT, the superficial or ventral part of the AA continues caudally until it merges with medial amygdaloid nucleus. Laterocaudally, the rostral pole of the anterior cortical nucleus intervenes between the AA and the brain surface. In the ventral part of the AA, cells of different sieze and shape are found within the molecular layer as the boundary line between sublaminae 1-alpha and !A, a characteristic arrangement the ventral AA shares only with the ACo and BAOT. Rostrodorsally, where the AA borders with fundus striati, the AA stands out by its lesser packing density and larger cells. Caudodorsally and dorsomedially, it becomes continuous with the medial division of the central amygdaloid nucleus and with the sublenticular parts of the substantia innominata, respectively. At this location, it is very difficult to trace a boundary line. Around the LOT, the medium siezed predominantly spindle shaped AA neurons are arranged in a ring-like formation several rows thick, surrounding the LOT, except its ventral superficial side and at th exit point of the commissural stria terminalis.
Part type
gray matter
Nomenclature
de Olmos -1985
Endorsement
The approach used by the collator Mihail Bota is not endorsed by the author of the nomenclature.
