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Asymmetry of neuron numbers in the hippocampal formation of prenatally malnourished and normally nourished rats: A stereological investigation
Author(s) -
Lister James P.,
Tonkiss John,
Blatt Gene J.,
Kemper Thomas L.,
DeBassio William A.,
Galler Janina R.,
Rosene Douglas L.
Publication year - 2006
Publication title -
hippocampus
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.767
H-Index - 155
eISSN - 1098-1063
pISSN - 1050-9631
DOI - 10.1002/hipo.20221
Subject(s) - subiculum , hippocampal formation , dentate gyrus , neuroscience , hippocampus , neuron , neocortex , stereology , biology , anatomy , chemistry , endocrinology
There is considerable evidence for lateralization of hippocampal function and hemispheric asymmetry in humans. In the rat, studies have reported asymmetries in the thicknesses of layers, the volumes of hippocampal subfields, and the density of cells at specific points along the septotemporal axis. To determine if there is an asymmetry of neuron numbers and whether prenatal malnutrition affects any asymmetries, 90‐day old male Sprague–Dawley rats that were either normally nourished or malnourished prenatally were perfused with 4% paraformaldehyde and the brains cut into 30‐μm sections. One interrupted series of sections through the entire hippocampus was analyzed stereologically to estimate the total number of neurons in the hilus of the dentate gyrus, the CA3/CA2 stratum pyramidale (SP), the CA1 SP, and the SP of the prosubiculum/subiculum of both hemispheres. Significant asymmetries ( P < 0.05) were found in the CA1 and CA3/CA2 subfields, with the right hemisphere containing 21 and 6% fewer neurons, respectively. Malnutrition reduced neuron numbers in the CA1 subfield by 12%, but did not alter the hemispheric asymmetry. Our findings agree with previous reports of left dominant asymmetries in the rat brain and suggest that this may result from differences in total numbers of neurons. © 2006 Wiley‐Liss, Inc.