Social isolation increases the density of [125I]omega-conotoxin GVIA binding sites in the rat frontal cortex and caudate nucleus.
Rats were reared from weaning either in isolation or in social groups for 12 weeks. Potential isolation-related changes in L- and N-type voltage-sensitive calcium channels (VSCCs) were assessed by the in vitro binding of [3H]isradipine (100 pM) and [125I]omega-conotoxin GVIA (4 pM) to membranes prepared from three discrete central nervous system regions: frontal cortex, caudate nucleus and hippocampus. The [3H]isradipine binding was generally not affected by isolation. However, [125I]omega-conotoxin GVIA binding was significantly higher in frontal cortex (52%) and caudate nucleus (75%) of isolated rats when compared with socially reared controls. The increased [125I]omega-conotoxin GVIA binding reflected an elevated density of binding sites without an alteration of receptor affinity. The possible contribution of an increased density of neuronal N-VSCCs (as labeled with [125I]omega-conotoxin GVIA) to the behavioral and neurochemical changes observed in 'isolation syndrome' is discussed.
Czyrak
A
A
Institute of Pharmacology, Polish Academy of Sciences, Cracow.
Dooley
D J
DJ
Jones
G H
GH
Robbins
T W
TW
D000818:Animals; D002121:Calcium Channel Blockers / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism*; D002421:Caudate Nucleus / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004095:Dihydropyridines / Q000378:metabolism*; D005260:Female; D005625:Frontal Lobe / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism; D007457:Iodine Radioisotopes; D017275:Isradipine; D008978:Mollusk Venoms / Q000378:metabolism*; D009928:Organ Specificity; D010456:Peptides, Cyclic / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D012016:Reference Values; D012934:Social Isolation; D020866:omega-Conotoxin GVIA
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D004095:Dihydropyridines; D007457:Iodine Radioisotopes; D008978:Mollusk Venoms; D010456:Peptides, Cyclic; D017981:Receptors, Neurotransmitter; C053157:omega-conotoxin receptor; D020866:omega-Conotoxin GVIA; D017275:Isradipine