Immunohistochemical localization of the sigma1 receptor in Schwann cells of rat sciatic nerve.
The sigma-1 (sigma(1)) receptors can bind different psychotropic drugs and have been implicated in schizophrenia, depression and dementia. The cloning of the sigma(1)-receptor has allowed to obtain specific antibodies and, in a recent immunohistochemical study, we demonstrated that, in addition to neurons, the sigma(1)-receptor is located in oligodendrocytes [Brain Res. 961 (2003) 92.]. In the present study using in vivo and in vitro techniques, we demonstrate the localization of the sigma(1)-receptor in Schwann cells. Double immunofluorescence studies showed that sigma(1)-receptor co-localized with S100 protein, a specific marker of Schwann cells, in both rat sciatic nerve Schwann cells and Schwann cells in cultures. The sigma(1)-receptor immunoreactivity was seen in the cytoplasm and paranodal region formed by these cells, but not in myelin itself. The presence of sigma(1)-receptor in oligodendrocytes and Schwann cells is discussed on the basis on recent findings involving this receptor in lipid metabolism, compartmentalization and transport to the plasma membrane, thus suggesting a role for sigma(1)-receptor signaling in myelination.
Palacios
Gabriel
G
Histopathology Unit, Research Center, Laboratorios del Dr. Esteve, S.A., Av. Mare de Déu de Montserrat 221, 08041 Barcelona, Spain. gpalacios@esteve.es
Muro
Asunción
A
Verdú
Enric
E
Pumarola
Martí
M
Vela
José Miguel
JM
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D007124:Immunoenzyme Techniques / Q000379:methods; D007150:Immunohistochemistry; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D017480:Receptors, sigma / Q000378:metabolism*; D009418:S100 Proteins / Q000378:metabolism; D012583:Schwann Cells / Q000378:metabolism*; D012584:Sciatic Nerve / Q000166:cytology*
D017480:Receptors, sigma; D009418:S100 Proteins; C101491:sigma1-binding protein, rat