GABAA receptor subunits identified in Paramecium by immunofluorescence confocal microscopy.
The presence of opioid, beta-adrenergic and cholinergic receptors has been demonstrated in ciliated protozoa, but little is known about gamma-aminobutyric acid (GABA) receptors. In this study we have analyzed the distribution of GABA(A)-type receptor subunits in Paramecium. Confocal laser microscopy using antibodies specific for alpha(1)-, alpha(2)-, alpha(3)-, alpha(6)-, beta(2/3)-, gamma(2)-, epsilon-, lambda-, and theta-subunits showed that most receptors are aggregated in clusters and are distributed both on cell surface and in the cytoplasm. The intensity of labelling of the alpha(6)-, beta(2/3)- and gamma(2)-subunits was more intense than the alpha(1)-, epsilon-, and theta-subunits, suggesting that the former are present in higher concentrations than the latter.
Ramoino
Paola
P
Department for the Study of the Territory and its Resources (DIP.TE.RIS.), University of Genoa, Corso Europa 26, I-16132 Genoa, Italy. ramoino@dipteris.unige.it
Scaglione
Silvia
S
Diaspro
Alberto
A
Beltrame
Francesco
F
Fato
Marco
M
Usai
Cesare
C
D000818:Animals; D000918:Antibody Specificity; D005455:Fluorescent Antibody Technique; D018613:Microscopy, Confocal / Q000379:methods; D010247:Paramecium / Q000737:chemistry* / Q000276:immunology; D011963:Receptors, GABA-A / Q000032:analysis* / Q000276:immunology
D011963:Receptors, GABA-A