Reproductive status regulates expression of sex steroid and GnRH receptors in the olfactory bulb.
Neuromodulators including gonadotropin-releasing hormone (GnRH) and sex steroids help integrate an animal's internal physiological state with incoming external cues, and can have profound effects on the processing of behaviorally relevant information, particularly from the olfactory system. While GnRH and steroid receptors are present in olfactory processing regions across vertebrates, little is known about whether their expression levels change with internal physiological state or external social cues. We used qRT-PCR to measure mRNA levels of two GnRH receptors (GnRH-R1, GnRH-R2), five sex steroid receptors (estrogen receptors: ERalpha, ERbetaa, ERbetab; androgen receptors: ARalpha, ARbeta), and aromatase in the olfactory bulb of the highly social African cichlid fish Astatotilapia burtoni. We asked whether these receptor levels changed with reproductive condition in females, or with social status, which regulates reproductive capacity in males. Our results reveal that mRNA levels of multiple sex steroid, GnRH receptor subtypes, and aromatase in the olfactory bulb vary with sex, social status in males, and reproductive condition in females, which highlights the potential importance of changing receptor levels in fine-tuning the olfactory system during the reproductive cycle. Further, steroid receptor mRNA levels were positively correlated with circulating steroid levels in males, but negatively correlated in females, suggesting different regulatory control between sexes. These results provide support for the hypothesis that the first-order olfactory relay station is a substrate for both GnRH and sex steroid modulation, and suggest that changes in receptor levels could be an important mechanism for regulating reproductive, social, and seasonal plasticity in olfactory perception observed across vertebrates.
Maruska
Karen P
KP
Biology Department, Stanford University, 371 Serra Mall, Stanford, CA 94305, USA. maruska@stanford.edu
Fernald
Russell D
RD
D000818:Animals; D001141:Aromatase / Q000096:biosynthesis; D023681:Cichlids; D004958:Estradiol / Q000097:blood; D047628:Estrogen Receptor alpha / Q000096:biosynthesis*; D047629:Estrogen Receptor beta / Q000096:biosynthesis*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D008297:Male; D009830:Olfactory Bulb / Q000378:metabolism*; D011944:Receptors, Androgen / Q000096:biosynthesis*; D011966:Receptors, LHRH / Q000096:biosynthesis*; D012098:Reproduction / Q000502:physiology*; D012727:Sex Characteristics; D013739:Testosterone / Q000031:analogs & derivatives / Q000097:blood
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D011944:Receptors, Androgen; D011966:Receptors, LHRH; D013739:Testosterone; D004958:Estradiol; D001141:Aromatase; C003600:11-ketotestosterone
J Neurophysiol. 2003 Aug;90(2):731-8
12672784
Z Tierpsychol. 1980;52(2):113-34
7386068
J Chem Ecol. 2008 Apr;34(4):438-49
18379847
Chem Senses. 2006 Jan;31(1):69-77
16322086
Zoolog Sci. 2009 Oct;26(10):669-80
19832678
J Comp Neurol. 2005 Feb 28;483(1):91-113
15672394
Gen Comp Endocrinol. 2003 Jul;132(3):399-408
12849963
Brain Res Mol Brain Res. 2005 Dec 7;142(1):39-46
16253385
Behav Genet. 1996 Sep;26(5):497-504
8917948
BMC Biol. 2007 Dec 12;5:54
18076759
Neuroendocrinology. 1985 Aug;41(2):163-8
3900788
J Comput Biol. 2005 Oct;12(8):1047-64
16241897
J Neurosci Res. 2007 Jun;85(8):1656-67
17465028
Gen Comp Endocrinol. 1969 Aug;13(1):92-7
5804512
J Exp Biol. 2005 Jun;208(Pt 11):2037-43
15914647
Cell Res. 2001 Dec;11(4):321-4
11787778
J Comp Neurol. 2005 Jun 20;487(1):28-41
15861460
Endocrinology. 2007 Oct;148(10):5060-71
17595228
Gen Comp Endocrinol. 1997 May;106(2):155-68
9169111
Physiol Behav. 2009 May 25;97(2):213-28
19272398
Horm Behav. 2007 Jan;51(1):164-70
17081541
Endocrinology. 2001 May;142(5):1737-43
11316736
Horm Behav. 1996 Mar;30(1):2-12
8724173
J Neurobiol. 2005 May;63(2):126-45
15702474
Comp Biochem Physiol A Mol Integr Physiol. 2007 May;147(1):77-83
17293144
BMC Neurosci. 2010 Apr 30;11:58
20433748
Gen Comp Endocrinol. 1966 Dec;7(3):482-91
5962650
Experientia. 1974 Dec 15;30(12):1394-5
4442523
J Chem Neuroanat. 2008 Jul;35(4):326-33
18439800
Brain Res. 2007 Jun 25;1155:34-41
17490623
Front Neuroendocrinol. 2006 Sep;27(3):247-74
16828853
Proc Natl Acad Sci U S A. 1999 Nov 23;96(24):14171-6
10570217
Endocrinology. 2001 Sep;142(9):4015-25
11517181
Chem Senses. 2005 Jan;30 Suppl 1:i309-10
15738173
Comp Biochem Physiol B Biochem Mol Biol. 2009 Aug;153(4):340-7
19398033
Brain Res. 1990 Mar 26;512(1):89-94
2186846
Brain Res Brain Res Rev. 2003 Oct;43(2):192-206
14572914
Horm Behav. 2004 Sep;46(3):356-61
15325236
Keio J Med. 2001 Jun;50(2):81-5
11450596
Gen Comp Endocrinol. 2003 Oct 1;133(3):358-67
12957480
J Comp Neurol. 2006 Mar 20;495(3):314-23
16440293
Chem Senses. 2010 Jan;35(1):65-74
19965901
J Mol Endocrinol. 2005 Jun;34(3):597-601
15956331
Behav Brain Res. 2006 Jun 30;170(2):342-6
16580741
Nucleic Acids Res. 2001 May 1;29(9):e45
11328886
Behav Brain Res. 2009 Jun 25;200(2):336-45
19146885
Gen Comp Endocrinol. 2005 May 15;142(1-2):60-6
15862549
J Exp Biol. 2002 Sep;205(Pt 17):2567-81
12151363
Brain Res Dev Brain Res. 2000 Feb 7;119(2):187-94
10675768
J Neurosci. 2001 Nov 15;21(22):8943-55
11698605
J Neurosci. 2000 Jun 1;20(11):3947-55
10818129
J Comp Neurol. 2010 Feb 15;518(4):493-512
20020540
Horm Behav. 2003 Aug;44(2):110-8
13129482
J Comp Neurol. 2007 Sep 1;504(1):57-73
17614300
Comp Biochem Physiol. 1967 Jul;22(1):209-25
6049988
J Comp Neurol. 1985 Aug 8;238(2):202-17
4044911
Brain Behav Evol. 2009;74(2):110-20
19729898
Chem Senses. 2008 Feb;33(2):119-23
17962228
J Neurosci. 1993 Feb;13(2):516-33
7678856
J Chem Ecol. 2008 Jul;34(7):898-914
18521679
Comp Biochem Physiol B Biochem Mol Biol. 2001 Jun;129(2-3):645-51
11399501
Z Tierpsychol. 1975 Apr;37(3):274-97
1231426