Dopaminergic innervation of rat locus coeruleus: a light and electron microscopic immunohistochemical study.
Dopaminergic innervation of the rat locus coeruleus (LC) was immunohistochemically studied by using monoclonal antibody directed against dopamine (DA) at the light- and electron-microscopic levels. A dense plexus of DA-immunoreactive (IR) varicose fibers was found not only in the cell body area of the LC but also in the dendritic area. Three hundred and forty DA-IR terminal boutons were observed. They were distributed in a wide range of diameters of 0.1-1.8 microns but most of them were large (mean value: 0.98 micron). Sixty-nine percent formed an asymmetric synapse. There were many axo-spinous connections. Small dendrites less than 0.3 micron in diameter displaying synaptic specialization were mostly dendritic spines (75%). Most of the target dendrites seemed to be noradrenergic in nature. It is suggested that dopaminergic innervation may play a powerful role in control mechanisms of activity of NA-containing neurons of the LC.
Department of Anatomy, Shiga University of Medical Science, Otsu, Japan.
T
T
Maeda
K
K
Kitahama
M
M
Geffard
D000818:Animals; D003712:Dendrites / Q000737:chemistry / Q000648:ultrastructure; D004298:Dopamine / Q000032:analysis*; D007150:Immunohistochemistry; D008125:Locus Coeruleus / Q000737:chemistry* / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron; D009412:Nerve Fibers / Q000737:chemistry* / Q000648:ultrastructure*; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000737:chemistry / Q000648:ultrastructure
D004298:Dopamine