Vertebrates sense chemical stimuli through the olfactory receptor neurons whose axons project to the main olfactory bulb. The main projections of the olfactory bulb are directed to the olfactory cortex and olfactory amygdala (the anterior and posterolateral cortical amygdalae). The posterolateral cortical amygdaloid nucleus mainly projects to other amygdaloid nuclei; other seemingly minor outputs are directed to the ventral striatum, in particular to the olfactory tubercle and the islands of Calleja.
Laboratorio de Neuroanatomía Humana, Departamento de Ciencias Médicas, Facultad de Medicina, Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, 02006 Albacete, Spain. Isabel.Ubeda@uclm.es