Pyramidal neuron types in field CA2 of the guinea pig.
The aim of the present study was to obtain information about the pyramidal neuron types in hippocampal field CA2 of the guinea pig. The apical and basal dendritic trees and the somata of CA2 pyramidal neurons were analyzed and quantified in Golgi-stained brains of adult guinea pigs of both sexes. Most of field CA2 pyramidal neurons (92%) had a single apical shaft (monoapical neurons) and very few neurons (8%) had two apical shafts (biapical neurons). The monoapical neurons were subdivided into three classes on the basis of the pattern of their apical tree. Morphometric analysis showed differences among the different neuron classes in the number of apical and basal dendritic branches, in the spread of the apical tree, in shaft dimensions and in soma diameters. Several morphometric sex differences were also found for two of the three monoapical neuron classes and for the biapical neurons. The results demonstrate that field CA2 of the guinea pig contains four different types of pyramidal neurons and that also this small hippocampal field is characterized, like the other hippocampal fields, by the presence of a heterogeneous population of pyramidal neurons.
Bartesaghi
R
R
Dipartimento di Fisiologia Umana e Generale, Università di Bologna, Italy. rbart@biocfarm.unibo.it
Ravasi
L
L
D000818:Animals; D003712:Dendrites / Q000648:ultrastructure; D005260:Female; D006168:Guinea Pigs; D006624:Hippocampus / Q000166:cytology*; D008297:Male; D009474:Neurons / Q000648:ultrastructure; D017966:Pyramidal Cells / Q000648:ultrastructure*