The dendritic morphology of pyramidal neurons in the rat hippocampal CA3 area. I. Cell types

Brain Res. 1989 Feb 6;479(1):105-14. doi: 10.1016/0006-8993(89)91340-1.


Pyramidal neurons from the hippocampal CA3 area of hooded rats were qualitatively and quantitatively described from Golgi-stained tissue. The most numerous of the pyramidal neurons, those with a single apical shaft, fell into two major categories. One category, termed short-shaft pyramidal neurons, is characterized by short apical shafts, a large number of thorny excrescences, and densely branched apical and basilar trees. The second category, long-shaft pyramidal neurons, is characterized by a long apical shaft, a small number of thorny excrescences and relatively less dendritic branching in both the apical and basilar trees. The somata of short-shaft pyramidal neurons tend to be located higher in stratum pyramidale than the somata of long-shaft neurons. Quantitative measurements, which included both analysis of dendritic branching and the distribution of dendritic material sampled at 10% intervals from the cell body, confirmed the qualitative observation that short-shaft neurons had more total dendritic length than long-shaft neurons. The difference in the total dendritic length observed between long- and short-shaft pyramidal neurons could be an indication that each type receives a different number of synapses per neuron. The less commonly observed variants of pyramidal neurons were briefly described but not quantified. This study demonstrates that CA3 pyramidal neurons are not a homogeneous group but that their heterogeneous characteristics fall into two major categories.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Count
  • Dendrites / ultrastructure*
  • Female
  • Hippocampus / cytology*
  • Male
  • Neurons / classification
  • Neurons / cytology*
  • Rats
  • Silver
  • Staining and Labeling


  • Silver