A group of structures defined by connectivity, namely, structures that receive axons from the olfactory bulb. They include the anterior olfactory nucleus, the anterior perforated substance, the rostral part of the medial amygdaloid nucleus (anterior cortical nucleus of amygdala), and structures in the anterior part of the parahippocampal gyrus, namely, the prepyriform area, most of the periamygdaloid area, and the rostral part of the entorhinal area (Price-90). Note that some authors have regarded the olfactory bulb itself as the primary olfactory area and the areas to which it projects as secondary (Anthoney-94). In the mouse (Dong-2004) and the rat (Swanson-2004), olfactory areas include the olfactory bulb, accessory olfactory bulb, anterior olfactory nucleus, tenia tecta, prepyriform area, postpiriform transition area, piriform amygdaloid area, nucleus of lateral olfactory tract, and cortical amygdaloid area. [ ]