Abstract
The present investigation has examined which subunits of the GABAA receptor are expressed by gonadotropin-releasing hormone (GnRH) neurons in the juvenile and adult male mouse. Cells of defined morphology, located in the medial septum (MS) and rostral preoptic area (POA), were patch-clamped in the acute brain slice preparation and their cell contents extracted. A reverse transcriptase polymerase chain reaction (RT-PCR) procedure using nested primers was used to establish individual GnRH mRNA-expressing cells which were then evaluated for eleven GABAA receptor (α1–5, β1–3, γ1–3) subunit transcripts. Single and multiple GABAA receptor subunit mRNAs were detected in approximately 70% of all GnRH neurons. A range of different subunit mRNAs (α1, α2, α5, β1, β2, β3, γ2) were found in juvenile GnRH neurons, with the α1γ2 and α5γ2 combinations encountered most frequently within individual cells. The expression profile in adult GnRH neurons was more extensive than that detected in juveniles with α1, α2, α3, α5, β1, β2, β3, γ1 and γ2 subunits all being detected. The major difference in subunit profile between GnRH neurons located in the MS and POA involved the β subunits. The principal postnatal developmental change was one of increasing overall subunit heterogeneity in maturing POA GnRH neurons. The profile of GABAA receptor subunit mRNAs detected in male GnRH neurons was quite different to that reported by us for female GnRH neurons in the mouse using the same RT-PCR approach. Together, these findings indicate that postnatal GnRH neurons are likely to express a range of GABAA receptor subunit mRNAs in a sexually dimorphic and developmentally-regulated manner.
References
1.
Wood RI, Foster DL: Sexual differentiation of reproductive neuroendocrine function in sheep. Rev Reprod 1998:3:130–140.
2.
Barraclough CA, Gorski RA: Evidence that the hypothalamus is responsible for androgen-induced sterility in the female rat. Endocrinology 1961;68:68–79.
3.
Gogan F, Beattie IA, Hery M, Laplante E, Kordon C: Effect of neonatal administration of steroids or gonadectomy upon oestradiol-induced luteinizing hormone release in rats of both sexes. J Endocrinol 1980;85:69–74.
4.
Handa RJ, Corbier P, Shryne JE, Schoonmaker JN, Gorski RA: Differential effects of the perinatal steroid environment on three sexually dimorphic parameters of the rat brain. Biol Reprod 1985;32:855–864.
5.
Herbosa CG, Dahl GE, Evans NP, Pelt J, Wood RI, Foster DL: Sexual differentiation of the surge mode of gonadotropin secretion: Prenatal androgens abolish the gonadotropin-releasing hormone surge in the sheep. J Neuroendocrinol 1996;8:627–633.
6.
Steiner RA, Clifton DK, Spies HG, Resko JA: Sexual differentiation and feedback control of luteinizing hormone secretion in the rhesus monkey. Biol Reprod 1976;15:206–212.
7.
Gay VL, Midgley R: Response of the adult rat to orchidetomy and ovariectomy as determined by LH radioimmunoassay. Endocrinology 1969;84:1359–1364.
8.
Yamamoto M, Diebel ND, Bogdanove EM: Analysis of initial and delayed effects of orchidectomy and ovariectomy on pituitary and serum LH levels in adult and immature rats. Endocrinology 1970;86:1102–1111.
9.
Luderer U, Schwartz NB: Sex differences in acute luteinizing hormone responses to gonadectomy remain after progesterone antagonist and dopamine agonist treatment. Biol Reprod 1991;45:918–926.
10.
MacLusky NJ, Naftolin F: Sexual differentiation of the central nervous system. Science 1981;211:1294–1303.
11.
Herbison AE: Multimodal influence of estrogen upon gonadotropin-releasing hormone neurons. Endocr Rev 1998;19:302–330.
12.
Wray S, Gainer H: Effect of neonatal gonadectomy on the postnatal development of LHRH cell subtypes in male and female rats. Neuroendocrinology 1987;45:413–419.
13.
Wood RI, Newman SW, Lehman MN, Foster DJ: GnRH neurons in the fetal lamb hypothalamus are similar in male and females. Neuroendocrinology 1992;55:427–433.
14.
Chen WP, Witkin JW, Silverman AJ: Sexual dimorphism in the synaptic input to gonadotropin-releasing hormone neurons. Endocrinology 1990;126:695–702.
15.
Kim SJ, Foster DL, Wood RI: Prenatal testosterone masculinizes synaptic input to gonadotropin-releasing hormone neurons in sheep. Biol Reprod 1999;61:599–605.
16.
Simerly RB: Organization and regulation of sexually dimorphic neuroendocrine pathways. Behav Brain Res 1998;92:195–203.
17.
Herbison AE, Chapman C, Dyer RG: Role of medial preoptic GABA neurones in regulating luteinizing secretion in the ovariectomised rat. Exp Brain Res 1991;87:345–352.
18.
Jarry H, Leonhardt S, Wuttke W: Gamma-aminobutyric acid neurons in the preoptic/anterior hypothalamic area synchronize the phasic activity of the gonadotropin-releasing hormone pulse generator in ovariectomized rats. Neuroendocrinology 1991;53:261–267.
19.
Herbison AE, Dyer RG: Effect on luteinizing hormone secretion of GABA receptor modulation in the medial preoptic area at the time of proestrous luteinizing hormone surge. Neuroendocrinology 1991;53:317–320.
20.
Scott CJ, Clarke IJ: Evidence that changes in the function of the subtypes of the receptors for gamma-aminobutyric acid may be involved in the seasonal changes in the negative-feedback effects of oestrogen on gonadotropin-releasing hormone secretion and plasma luteinizing hormone levels in the ewe. Endocrinology 1993;133:2904–2912.
21.
Kimura F, Jinnai K: Bicuculline infusions advance the timing of luteinizing hormone surge in progesterone rats: Comparisons with naloxone effects. Horm Behav 1994;28:24–430.
22.
Mitsushima D, Hei DL, Terasawa E: Gamma-aminobutyric acid is an inhibitory neurotransmitter-restricting the release of luteinizing hormone-releasing hormone before the onset of puberty. Proc Natl Acad Sci USA 1994;91:395–399.
23.
Robinson JE: Gamma-aminobutyric acid and the control of GnRH secretion in sheep. J Reprod Fertil 1995;49:221–230.
24.
Keen KL, Burich AJ, Mitsushima D, Kasuya E, Terasawa E: Effects of pulsatile infusion of the GABAA receptor blocker bicuculline on the onset of puberty in female rhesus monkeys. Endocrinology 1999;140:5257–5266.
25.
Leranth C, MacLusky NJ, Sakamoto H, Shanabrough M, Naftolin F: Glutamic acid decarboxylase-containing axons synapse on LHRH neurons in the rat medial preoptic area. Neuroendocrinology 1985;40:536–539.
26.
Petersen SL, McCrone S, Coy D, Adelman JP, Mahan LC: GABAA receptor subunit mRNAs in cells of the preoptic area: Colocalization with LHRH mRNA using dual-label in situ hybridization histochemistry. Endocrine 1993;1:29–34.
27.
Jung H, Shannon EM, Fritschy JM, Ojeda SR: Several GABAA receptor subunits are expressed in LHRH neurons of juvenile female rats. Brain Res 1998;780:218–229.
28.
Searles RV, Yoo MJ, He JR, Shen WB, Selmanoff M: Sex differences in GABA turnover and glutamic acid decarboxylase (GAD65 and GAD67) mRNA in the rat hypothalamus. Brain Res 2000;878:11–19.
29.
Yoo MJ, Searles RV, He JR, Shen WB, Grattan DR, Selmanoff M: Castration rapidly decreases hypothalamic γ-aminobutyric acidergic neuronal activity in both male and female rats. Brain Res 2000;878:1–10.
30.
Szwarcfarb B, Carbone S, Stein ML, Medina J, Moguilevsky JA: Sexual differences in the effect of the GABAergic system on LH secretion and in the hypothalamic ontogenesis of GABAA receptors in prepubertal rats. Brain Res 1994;646:351–355.
31.
Spergel DJ, Kruth U, Shimshek DR, Sprengel R, Seeburg PH: Using reporter genes to label selected neuronal populations in transgenic mice for gene promoter, anatomical, and physiological studies. Prog Neurobiol 2001;63:673–686.
32.
Herbison, AE: GnRH transgenic models; in Castro MG (ed): Transgenic Models in Endocrinology. Boston, Kluwer Academic, 2001.
33.
Herbison AE, Pape JR, Simonian SX, Skynner MJ, Sim JA: Molecular and cellular properties of GnRH neurons revealed through transgenics in the mouse. Mol Cell Endocrinol 2001, in press.
34.
Spergel DJ, Kruth U, Hanley DF, Sprengel R, Seeburg PH: GABA- and glutamate-activated channels in green fluorescent protein-tagged gonadotropin-releasing hormone neurone in transgenic mice. J Neurosci 1999;19:2037–2050.
35.
Sim JA, Skynner MJ, Paper JR, Herbison AE: Late postnatal reorganization of GABAA receptor signalling in native GnRH neurons. Eur J Neurosci 2000;12:3497–3504.
36.
Sim JA, Skynner MJ, Herbison AE: Heterogeneity in the basic membrane properties of postnatal gonadotropin-releasing hormone neurons in the mouse. J Neurosci 2001;21:1067–1075.
37.
Monyer H, Jonas P: Polymerase chain reaction analysis of ion channel expression in single neurons of brain slices; in Sakmann B, Neher E (eds): Single-Channel Recording. New York, Plenum Press, 1995, vol 16, pp 357–373.
38.
Ruano D, Perrais D, Rossier J, Ropert N: Expression of GABAA receptor subunit mRNAs by layer V pyramidal cells of the rat primary visual cortex. Eur J Neurosci 1997;9:857–862.
39.
Skynner MJ, Sim JS, Herbison AE: Detection of estrogen receptor α and β messenger ribonucleic acids in adult gonadotropin-releasing hormone neurons. Endocrinology 1999;140:5195–5201.
40.
Silverman A, Livne I, Witkin JW: The gonadotrophin-releasing hormone (GnRH), neuronal systems: Immunocytochemistry and in situ hybridization; in Knobil E, Neill JD (eds): The Physiology of Reproduction. New York, Raven Press, 1994, pp 1683–1706.
41.
Yan Z, Surmeier DJ: D5 dopamine receptors enhance Zn2+-sensitive GABAA currents in striatal cholinergic interneurons through a PKA-PP1 cascade. Neuron 1997;19:1115–1126.
42.
Gustincich S, Feigenspan A, Sieghart W, Raviola E: Composition of the GABAA receptors of retinal dopaminergic neurons. J Neurosci 1999;19:7812–7822.
43.
Dixon AK, Richardson PJ, Pinnock RD, Lee K: Gene-expression analysis at the single-cell level. Trends Pharmacol 2000;21:65–70.
44.
Herbison AE, Fenelon VS: Estrogen regulation of GABAA receptor subunit mRNA expression in preoptic area and bed nucleus of the stria terminalis of female rat brain. J Neurosci 1995;15:2328–2337.
45.
Clark AS, Myers M, Robinson S, Chang P, Henderson LP: Hormone-dependent regulation of GABAA receptor gamma subunit mRNAs in sexually dimorphic regions of the rat brain. Proc R Soc Lond B Biol Sci 1998;265:1965–1859.
46.
Sieghart W: Structure and pharmacology of γ-aminobutyric acidA receptor subtypes. Pharmacol Rev 1995;47:181–234.
47.
Nett ST, Jorge-Rivera JC, Myers M, Clark AS, Henderson LP: Properties and sex-specific differences of GABAA receptors in neurons expressing γ1 subunit mRNA in the preoptic area of the rat. J Neurophysiol 1999;81:192–203.
48.
Mitsushiima D, Kimura F: The maturation of GABA(A) receptor-mediated control of luteinizing hormone secretion in immature male rats. Brain Res 1997;748:258–62.
49.
Feleder C, Jarry H, Leonardt S, Wuttke W, Moguilevsky JA: The GABAergic control of gonadotropin-releasing hormone secretion in male rats during sexual maturation involves effects on hypothalamic excitatory and inhibitory amino acid systems. Neuroendocrinology 1996;64:305–312.
50.
Bourguignon JR, Gérard A, Purnelle G, Czajkowski V, Yamanaka C, Lemaître M, Rigo JM, Moonen G, Franchimont P: Duality of glutamatergic and gabaergic control of pulsatile GnRH secretion by rat hypothalamic explants. I. Effects of antisense oligodeoxynucleotides using explants including or excluding the preoptic area. J Neuroendocrinol 1997;9:183–191.
51.
Moguilevski JA, Carbone S, Szwarcfarb B, Rondina D: Sexual maturation modifies the GABAergic control of gonadotrophin secretion in female rats. Brain Res 1991;563:12–16.
52.
Rivera C, Voipio J, Payne JA, Ruusuvuori E, Lahtinen H, Lamsa K, Pirvola U, Saarma M, Kaila K: The K+/Cl– co-transporter KCC2 renders GABA hyperpolarizing during neuronal maturation. Nature 1999;397:251–255.
53.
McKernan RM, Whiting PJ: Which GABAA-receptor subtypes really occur in the brain? Trends Neurosci 1996;14:139–143.
54.
Masotto C, Wisniewski G, Negro-Vilar A: Different γ-aminobutyric acid receptor subtypes are involved in the regulation of opiate-dependent and independent luteinizing hormone-releasing hormone secretion. Endocrinology 1989;125:548–553.
55.
Akema T, Kimura F: 2-Hydroxysaclofen, a potent GABAB receptor antagonist, stimulates luteinizing hormone secretion in female rats. Brain Res 1991;546:143–145.
56.
Jackson GL, Wood SG, Kuehl DE: A γ-aminobutyric acidB agonist reverses the negative feedback effect of testosterone on gonadotropin-releasing hormone and luteinizing hormone secretion in the male sheep. Endocrinology 2000;141:3940–3945.
57.
Herbison AE, Heavens RP, Dye S, Dyer RG: Acute action of oestrogen on medial preoptic gamma-aminobutyric acid neurons: Correlation with oestrogen-negative feedback on luteinizing hormone secretion. J Neuroendocrinol 1991;3:101–106.
58.
Grattan DR, Rocca MS, Sagrillo CA, McCarthy MM, Selmanoff M: Antiandrogen microimplants into the rostral medial preoptic area decrease γ-aminobutyric acidergeic neuronal activity and increase luteinizing hormone secretion in the intact male rat. Endocrinology 1996;137:4167–4173.
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