Parvalbumin in the medial septum/diagonal band complex of the African green monkey Cercopithecus aethiops

The distribution of the calcium-binding protein Parvalbumin (PV), a marker for a subpopulation of GABAergic neurons, was studied in the septal complex of the African green monkey, Cercopithecus aethiops. PV-immunoreactive neurons were found in relatively small numbers in the medial septum and in large numbers in the nucleus of the diagonal band (BROCA). They were extremely rare in the dorsal and intermediate parts of the lateral septum. PV-immunoreactive neurons in the medial septum and the nucleus of the diagonal band were mostly fusiform when located close to the midline and round to polygonal in more lateral locations. Some perikarya of immunopositive as well as immunonegative cells were covered with immunostained boutons whereas others were not. Our present descriptive data suggest that there are no principal differences in PV-containing neurons in the septal region between non-human primates and rodents which have been analyzed in great detail in previous studies.