Open AccessElectron microscopic evidence for different myelination of rat septohippocampal fibres
Author(s) -
Ulrich Gärtner,
Wolfgang Härtig,
K Brauer,
Gert Brückner,
Thomas Arendt
Publication year - 2001
Publication title -
neuroreport/neuroreport
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.607
H-Index - 188
eISSN - 1473-558X
pISSN - 0959-4965
DOI - 10.1097/00001756-200101220-00011
Subject(s) - parvalbumin , cholinergic , neuroscience , choline acetyltransferase , myelin , gabaergic , cholinergic neuron , biology , anatomy , electron microscope , immunocytochemistry , central nervous system , inhibitory postsynaptic potential , endocrinology , physics , optics
Rat septohippocampal fibres are known to originate from GABAergic parvalbumin-containing, fast-firing, fast-conducting neurons and from cholinergic slow-firing, slow-conducting neurons. In the present electron microscopic study, based on immunocytochemical demonstration of parvalbumin and choline acetyltransferase in transverse and horizontal septal sections, it was shown that parvalbumin-immunoreactive fibres are myelinated, but the vast majority of cholinergic fibres are not. As revealed, especially in horizontal sections, the cholinergic axons show considerably finer calibres than parvalbumin-containing ones. These results confirm and extend our previous light microscopic findings. It can be concluded that differences in conduction velocities, presence or absence of myelin sheaths and differences axonal diameters are correlated in the septohippocampal pathway.