Quantitative analysis of the heteromeric neuronal nicotinic receptors in the rat hippocampus.
The objective of this study was to identify and quantify the heteromeric neuronal nicotinic receptors (nAChRs) in the rat hippocampus. The density of nAChR subtypes was assessed by labeling them with [(3)H]epibatidine ([(3)H]EB) followed by immunoprecipitation with subunit-selective antibodies. Sequential immunoprecipitation assays were used to establish associations between two different subunits, which then allowed the full subunit composition of the receptors to be deduced. Our results show that most of the hippocampal heteromeric nAChRs contain α4 and β2 subunits. In fact, we identified two populations containing these two predominant subunits, the α4β2 and α4β2α5 subtypes which account for ∼ 40% and ∼ 35%, respectively, of the total [(3)H]EB-labeled receptors. An additional heteromeric subtype with the subunit composition of α4β2α3 represented ∼ 10% of the total nAChRs, and another 10% of the immunoprecipitated receptors contained α4 and β4 subunits, with or without the α3 subunit. To determine if α4β2 and α4β2α5 nAChR subtypes differ in their ligand binding affinities, the α3- and β4-containing receptors were first removed by immunoprecipitation and then, competition studies with acetylcholine, nicotine, cytisine and sazetidine-A against [(3)H]EB were carried out on the remaining α4β2 and α4β2α5 subtypes. Results suggested these subtypes have comparable binding affinities for the nicotinic ligands used here.
Lomazzo
Ermelinda
E
Department of Pharmacology, Georgetown University School of Medicine, Washington, DC 20057, USA.
MacArthur
Linda
L
Yasuda
Robert P
RP
Wolfe
Barry B
BB
Kellar
Kenneth J
KJ
D000818:Animals; D001667:Binding, Competitive / Q000502:physiology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism*; D047468:Immunoprecipitation; D008024:Ligands; D008297:Male; D018722:Nicotinic Agonists / Q000378:metabolism; D011725:Pyridines / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011978:Receptors, Nicotinic / Q000378:metabolism*
D019086:Bridged Bicyclo Compounds, Heterocyclic; C499978:Chrna5 protein, rat; D008024:Ligands; D018722:Nicotinic Agonists; D011725:Pyridines; D011978:Receptors, Nicotinic; C403531:nicotinic receptor alpha4beta2; C082748:epibatidine
J Neurol Neurosurg Psychiatry. 1987 Jun;50(6):806-9
2956364
Mol Pharmacol. 2006 Oct;70(4):1454-60
16857741
Br J Pharmacol. 1996 Feb;117(4):595-606
8646402
Neuroscience. 1983 Dec;10(4):1185-201
6320048
J Biol Chem. 1990 Mar 15;265(8):4472-82
1689727
J Chem Neuroanat. 2006 Dec;32(2-4):179-90
17046198
Cancer Epidemiol Biomarkers Prev. 2008 Dec;17(12):3517-25
19029397
Trends Pharmacol Sci. 2004 Jun;25(6):317-24
15165747
J Neurochem. 2008 Jan;104(2):446-56
17961152
J Pharmacol Exp Ther. 1998 Jul;286(1):311-20
9655874
J Pharmacol Exp Ther. 2004 Jul;310(1):98-107
15016836
J Pharmacol Exp Ther. 1993 Jun;265(3):1455-73
8510022
Mol Pharmacol. 1998 Dec;54(6):1132-9
9855644
Neuroscience. 2004;124(4):817-22
15026122
Biophys J. 1991 Sep;60(3):721-7
1718469
Mol Psychiatry. 2008 Apr;13(4):368-73
18227835
J Physiol. 2002 Apr 15;540(Pt 2):425-34
11956333
J Comp Neurol. 2008 Nov 10;511(2):286-99
18792073
J Comp Neurol. 1989 Jun 8;284(2):314-35
2754038
Nature. 1996 Mar 28;380(6572):347-51
8598930
J Pharmacol Exp Ther. 1991 Sep;258(3):1127-36
1890617
J Pharmacol Exp Ther. 1997 Jan;280(1):346-56
8996215
J Neurochem. 2001 Jun;77(6):1581-9
11413241
J Neurochem. 2001 Oct;79(2):258-65
11677253
Neuron. 1992 Oct;9(4):679-91
1389183
Hum Mol Genet. 2007 Jan 1;16(1):36-49
17135278
J Neurochem. 1996 Nov;67(5):1953-9
8863500
J Neurosci. 1999 Apr 15;19(8):2887-96
10191306
Mol Pharmacol. 1992 Jan;41(1):31-7
1732720
Addiction. 2008 Sep;103(9):1544-52
18783506
Mol Pharmacol. 1994 Jan;45(1):142-9
8302273
Eur J Neurosci. 2009 Apr;29(8):1588-603
19385992
Proc Natl Acad Sci U S A. 1987 Jan;84(2):595-9
3467376
J Physiol. 2000 Sep 15;527 Pt 3:515-28
10990538
J Neurosci. 1991 Mar;11(3):837-45
1705971
J Neurosci. 1998 Nov 1;18(21):8571-9
9786965
Ann Neurol. 1982 Nov;12(5):494
7181455
Trends Pharmacol Sci. 2006 Sep;27(9):482-91
16876883
J Physiol. 1999 May 1;516 ( Pt 3):657-78
10200416
Neuroscience. 2003;119(4):965-77
12831856
Mol Pharmacol. 2004 Oct;66(4):978-87
15247319
Prog Brain Res. 2004;145:109-20
14650910
Mol Pharmacol. 2002 Jun;61(6):1416-22
12021403
Mol Pharmacol. 2007 Mar;71(3):769-76
17132685
J Pharmacol Exp Ther. 2007 Jul;322(1):306-15
17446303
J Neurosci. 2005 Oct 5;25(40):9258-65
16207885
Neuroreport. 1997 Jul 28;8(11):2433-6
9261804
Neuron. 1989 Nov;3(5):589-96
2484342
Mol Pharmacol. 2005 Dec;68(6):1656-68
16129735
J Biol Chem. 1991 Dec 5;266(34):23354-64
1744130
Clin Cancer Res. 2009 Mar 1;15(5):1837-42
19223495
J Biol Chem. 1989 Jul 25;264(21):12666-72
2568359
J Neurosci. 1992 Dec;12(12):4611-23
1464760
Mol Pharmacol. 2006 Nov;70(5):1693-9
16882879
Am J Psychiatry. 2008 Sep;165(9):1163-71
18519524
J Physiol. 1997 Nov 1;504 ( Pt 3):603-10
9401968
J Biol Chem. 1996 Jul 26;271(30):17656-65
8663494
J Neurosci. 2009 Jan 28;29(4):918-29
19176801
J Physiol. 1997 Apr 1;500 ( Pt 1):123-38
9097938