Persistence of the pars externa system of the anterior olfactory nucleus in a microsmatic primate, Callithrix jacchus.
The pars externa (PE) system of the anterior olfactory nucleus (AON) in a primate, Callithrix jacchus, was defined by its architecture and by its connection patterns with the main olfactory bulb (MOB) as revealed by tracing techniques. Focal, unilateral injections of wheat germ agglutinin-conjugated horseradish peroxidase into the MOB yielded ipsilaterally labelled afferent neurons in all subdivisions of the AON, with the exception of a clearly circumscribed area in the ventrolateral retrobulbar field of the basocaudal frontal lobe; in the contralateral hemisphere, this same area contained intensely stained neurons forming a horizontal flat plate of small neurons. This unique commissural connection pattern parallels the organization of the PE to MOB connection in sub-primates (Schoenfeld and Macrides, 1984, J. Comp. Neurol., 227: 121-135). Thus, despite earlier controversy (Crosby and Humphrey, 1939, J. Comp. Neurol., 71: 121-213), there appears to be a PE system in a microsmatic primate whose organization is quite similar to that in sub-primates.
Reyher
C K
CK
Department of Neuroanatomy, Freie Universität Berlin, F.R.G.
D000818:Animals; D002144:Callithrix / Q000033:anatomy & histology*; D002143:Callitrichinae / Q000033:anatomy & histology*; D002490:Central Nervous System / Q000033:anatomy & histology*; D006735:Horseradish Peroxidase; D008297:Male; D009830:Olfactory Bulb / Q000033:anatomy & histology*; D009833:Olfactory Pathways / Q000033:anatomy & histology*; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins
D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; D006735:Horseradish Peroxidase