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Synaptology of the proximal segment of pyramidal cell basal dendrites
Author(s) -
AlonsoNanclares L.,
White E. L.,
Elston G. N.,
DeFelipe J.
Publication year - 2004
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.0953-816x.2003.03166.x
Subject(s) - excitatory postsynaptic potential , neuroscience , postsynaptic potential , dendritic spine , somatosensory system , pyramidal cell , biology , basal (medicine) , inhibitory postsynaptic potential , anatomy , glutamate receptor , hippocampus , receptor , hippocampal formation , endocrinology , biochemistry , insulin
Abstract Pyramidal neurons are covered with dendritic spines, the main postsynaptic targets of excitatory (asymmetrical) synapses. However, the proximal portion of both the apical and basal dendrites is devoid of spines, suggesting a lack of excitatory inputs to this region. In the present study we used electron microscopy to analyse the proximal region of the basal dendrites of supra‐ and infragranular pyramidal cells to determine if this is the case. The proximal region of 80 basal dendrites sampled from the rat hindlimb representation in the primary somatosensory cortex was studied by electron microscopy. A total of 317 synapses were found within this region of the dendrites, all of which were of the symmetrical type. These results suggest that glutamate receptors, although present in the cytoplasm, are not involved in synaptic junctions in the proximal portion of the dendrites. These data further support the idea that inhibitory terminals exclusively innervate the proximal region of basal dendrites.