TY - JOUR
T1 - Ultrastructural relations between β-adrenergic receptors and catecholaminergic neurons
AU - Aoki, Chiye
AU - Pickel, Virginia M.
N1 - Funding Information:
We thank Catherine D. Strader for her generous gifts of antibodies against peptides corresponding to the intracellular third loop and C-terminal tail of BAR and Tong H. Joh for the antiserum against the whole PAR. We also would like to thank Strader for her criticisms of the manuscript. We appreciate the help of Adam Starr for the reproduction of electron micrographs. This work was funded by the following grants:E Y08055t o C.A.: MH40342t o V.M.P.
PY - 1992
Y1 - 1992
N2 - We performed dual electron microscopic immunocytochemistry to determine the precise cellular relations between β-adrenergic receptors (βAR) and Catecholaminergic terminals within adult rat brains. An antibody, βAR404, against a peptide corresponding to the C-terminus of the hamster lung βAR (β2 subtype) together with an anti-tyrosine hydroxylase (TH), a Catecholaminergic marker, were used. Results show predominant labeling for βAR404 within small astrocytic processes (β-A). This is in sharp contrast to earlier results which showed neuronal labeling when using antibodies against the third intracellular loop of the receptor and of neurons-plus-astrocytes labeled using antibodies against the whole βAR molecule. β-A within visual cortex and nuclei of the solitary tracts frequently contacted blood vessel basement membrane and TH-immunoreactive terminals. TH-immunoreactive axons forming axo-axonic juxtapositions with non-TH terminals were also noted to be surrounded by β-A. In the area postrema, a brain region lacking a blood-brain barrier, few β-A occurred adjacent to TH-immunoreactive terminals or elsewhere. Thus, 1) catecholamines may act beyond morphologically identifiable synapses; 2) β-A may mediate interactions between catecholamines and other transmitters; 3) there may be substantial heterogeneity in the structure or the conformation of the βAR protein between neurons and glia or across CNS regions.
AB - We performed dual electron microscopic immunocytochemistry to determine the precise cellular relations between β-adrenergic receptors (βAR) and Catecholaminergic terminals within adult rat brains. An antibody, βAR404, against a peptide corresponding to the C-terminus of the hamster lung βAR (β2 subtype) together with an anti-tyrosine hydroxylase (TH), a Catecholaminergic marker, were used. Results show predominant labeling for βAR404 within small astrocytic processes (β-A). This is in sharp contrast to earlier results which showed neuronal labeling when using antibodies against the third intracellular loop of the receptor and of neurons-plus-astrocytes labeled using antibodies against the whole βAR molecule. β-A within visual cortex and nuclei of the solitary tracts frequently contacted blood vessel basement membrane and TH-immunoreactive terminals. TH-immunoreactive axons forming axo-axonic juxtapositions with non-TH terminals were also noted to be surrounded by β-A. In the area postrema, a brain region lacking a blood-brain barrier, few β-A occurred adjacent to TH-immunoreactive terminals or elsewhere. Thus, 1) catecholamines may act beyond morphologically identifiable synapses; 2) β-A may mediate interactions between catecholamines and other transmitters; 3) there may be substantial heterogeneity in the structure or the conformation of the βAR protein between neurons and glia or across CNS regions.
KW - β-Adrenergic receptors β-Adrenoceptors Astrocytes Nucleus of the solitary tract Area postrema Visual cortex Catecholamines Ultrastructure Blood-brain barrier Synapse Circumventricular organ Area postrema
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U2 - 10.1016/0361-9230(92)90055-3
DO - 10.1016/0361-9230(92)90055-3
M3 - Article
C2 - 1327418
AN - SCOPUS:0026786980
SN - 0361-9230
VL - 29
SP - 257
EP - 263
JO - Brain Research Bulletin
JF - Brain Research Bulletin
IS - 3-4
ER -