The Spatial Relationship of γ-Aminobutyric Acid (GABA) Neurons and Gonadotropin-Releasing Hormone (GnRH) Neurons in Larval and Adult Sea Lamprey, &lt;i&gt;Petromyzon marinus&lt;/i&gt;

Reed, Karen L.; MacIntyre, Janet; Tobet, Stuart A.; Trudeau, Vance L.; MacEachern, L.; Rubin, Beverly S.; Sower, Stacia A.

doi:10.1159/000064117

Cited by 22 publications

(32 citation statements)

References 57 publications

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“…The α-decarboxylation of L-glutamic acid is a primary step in GABA synthesis and this reaction is catalysed by GAD (Reed et al 2002). The present findings suggest that an appropriate amount of MSG can stimulate GABA production.…”

Section: Identification Of Significant Variables By Plackett-burman Dsupporting

confidence: 53%

Screening and optimization of γ-aminobutyric acid production fromMonascus sanguineusunder solid-state fermentation

Dikshit

Tallapragada

2015

Frontiers in Life Science

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The aim of this study was to screen and optimize γ -aminobutyric acid (GABA) production from Monascus sanguineus. Different agro-waste residues were screened for GABA production. The GABA yield was confirmed by thin-layer chromatography and mass spectrometry. GABA was quantified using the simple ninhydrin protocol. Plackett-Burman and response surface methodology (RSM) as statistical tools were applied for screening and optimization of GABA yield. The accuracy of the RSM model was demonstrated by generating a non-statistical model using artificial neural network methodology. Coconut oil cake was the best substrate for GABA yield of all the tested substrates. Monosodium glutamate (MSG), pH and incubation period were found to favour GABA production. Maximum yield predicted from the RSM model was 15.53 mg/gds with an MSG concentration of 0.05 g at pH 7.5 and an incubation period of 20 days. This study considered an unexplored Monascus sp., M. sanguineus, which has primarily been used for pigment production. The capability of producing GABA from M. sanguineus using coconut oil cake as a substrate is an economical method with potential industrial use. The convincing results from this work could be considered as a benchmark for exploiting the Monascus strain to obtain GABA-enriched functional food for human consumption.

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Section: Identification Of Significant Variables By Plackett-burman Dsupporting

confidence: 53%

Screening and optimization of γ-aminobutyric acid production fromMonascus sanguineusunder solid-state fermentation

Dikshit

Tallapragada

2015

Frontiers in Life Science

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“…It is not clear whether GnRH I produced by the hypothalamus or by other tissues binds to and signals through these receptors throughout the body. At least for the brain, GnRHR I signaling is likely mediated through GnRH I produced by GnRH I neurons that extend throughout different regions of the brain (Tobet et al 1996, Quanbeck et al 1997, Kim et al 1999, Reed et al 2002. The short serum half-life of GnRH I (approximately 2-3 min; Redding et al 1973, Fauconnier et al 1978 would support autocrine release of GnRH I within the brain, although it has been shown in rats that GnRH I can cross the blood brain barrier (BBB) (Dvorska et al 1992).…”

Section: Functional Consequences Of Gnrh I Induction Of Lh Expressionmentioning

confidence: 99%

Human neurons express type I GnRH receptor and respond to GnRH I by increasing luteinizing hormone expression

Wilson¹,

Salamat²,

Haasl³

et al. 2006

Journal of Endocrinology

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Gonadotropin-releasing hormone receptor I (GnRHR I) has been localized to the limbic system of the rat brain, although the functional consequences of GnRH signaling through these receptors is unknown. In this paper, we characterize the expression of GnRHR I in the human hippocampus and cortex, and the functionality of GnRHR I in human neuroblastoma cells. Robust GnRHR I immunoreactivity was detected in the cell body as well as along the apical dendrites of pyramidal neurons in the CA2, CA1, and end plate, but was clearly lower in the subiculum of the hippocampus. Immunolabeling was also evident in cortical neurons, including those located in the entorhinal cortex and occipitotemporal gyrus but was not observed within the granular layer of the dentate gyrus. No differences in immunohistochemical staining were observed between control and Alzheimer's disease brain. GnRHR I mRNA and protein (mature, immature, and other variant) expression was detected in human neuroblastoma cells (M17, SH-SY5Y) and rat embryonic primary neurons and varied with differentiation and GnRH treatment. Since GnRHR I was expressed by extrapituitary cells, and hypothalamic GnRH I secretion markedly increases post-menopause/andropause, we treated human M17 neuroblastoma cells cultured in serum-free conditions with GnRH I for 6 h and measured LH expression. M17 neuroblastoma cells express LHb mRNA, while immunoblot analysis indicated the presence of three LH variants (approximately 30, 47, and 60 kDa) that were upregulated by low concentrations of GnRH I, but downregulated at higher GnRH I concentrations. LH expression was also found to increase in differentiating embryonic rat primary cortical neurons. Our results demonstrate that neurons expressing GnRHR I are functional, responding to GnRH I by upregulating LH production. Post-reproductive surges in GnRH I secretion may explain the accumulation of LH in pyramidal neurons of the aged human and rat.

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“…Few studies have examined the role of GABA on GnRH in fish and to date, only one previous study has examined the possibility of GABA-GnRH interactions in the hypothalamus of the sea lamprey. Previous immunocytochemical studies by Reed et al [2002] demonstrated the close spatial relationship between GABA-containing neurons and GnRH-containing neurons in the hypothalamus of the larval sea lamprey, hypothesizing that GABA is directly involved in controlling GnRH release. Using in situ hybridization, Reed et al also showed the expression of the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD) in close proximity to cells expressing GnRH-I in the hypothalamus of larval sea lamprey, although no comparisons between the expression of GAD and GnRH were made in the juvenile and adult sea lamprey.…”

Section: Introductionmentioning

confidence: 97%

“…Numerous immunocytochemistry (ICC) studies [Crim et al, 1979a, b;Nozaki and Kobayashi, 1979;Nozaki et al, 1984Nozaki et al, , 2000King et al, 1988;Wright et al, 1994;Tobet et al, 1995Tobet et al, , 1996Reed et al, 2002] have investigated the distribution of lamprey GnRH in the brain of several lamprey species. These studies have consistently demonstrated the localization of lamprey GnRH-I and -III in the preoptic area and hypothalamus extending to the neurohypophysis.…”

Section: Introductionmentioning

confidence: 99%

“…These studies have consistently demonstrated the localization of lamprey GnRH-I and -III in the preoptic area and hypothalamus extending to the neurohypophysis. Reed et al [2002] using in situ hybridization in larval lamprey, showed that lamprey GnRH-I mRNA was expressed in the same region of the preoptic area and regions of the hypothalamus adjacent to the third ventricle. In the Reed et al [2002] study lamprey GnRH-III had been identified, however, its cDNA had not yet been determined, preventing comparisons between lamprey GnRH-I and -III mRNA expression at different life stages of the sea lamprey.…”

Section: Introductionmentioning

confidence: 99%

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In situ Characterization of Gonadotropin- Releasing Hormone-I, -III, and Glutamic Acid Decarboxylase Expression in the Brain of the Sea Lamprey, <i>Petromyzon marinus</i>

et al. 2004

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The distribution of lamprey gonadotropin-releasing hormone (GnRH)-I and -III has been extensively characterized by immunocytochemistry in the forebrain of the sea lamprey, Petromyzon marinus. However, the cellular location of lamprey GnRH-III mRNA expression by in situ hybridization in the lamprey brain has not been determined. We show for the first time the location of expression of lamprey GnRH-III, as well as provide a more comprehensive in situ study of lamprey GnRH-I and glutamic acid decarboxylase (GAD; GABA-synthesizing enzyme) mRNA expression in the brain of the lamprey in different reproductive life stages. Colorimetric and dual-label fluorescent amplification methods of in situ hybridization were used on brain tissue sections of adult, juvenile, and larval sea lamprey. In each life stage of the lamprey, expression of lamprey GnRH-I was shown in the preoptic area (POA) and the hypothalamus forming the characteristic arc-like cell population extending from the preoptic nucleus (NPO) to the neurohypophysis. Lamprey GnRH-III expression was also seen in the POA of each life stage in close proximity to lamprey GnRH-I mRNA containing neurons. GAD expression was shown in distinct cell clusters in and around the POA, in the olfactory bulb, in the dorsal thalamus beneath the habenular region, and also in the ventral-medial hypothalamus stretching from the periventricular region to the anterior portion of the rhombencephalon. Using dual-label in situ hybridization, we have shown that lamprey GnRH-I and -III mRNA are colocalized in the same cells in the POA in adult lampreys. Dual-label in situ hybridization also showed close proximity of GAD mRNA containing neurons and GnRH containing neurons in the POA. These data suggest that γ-aminobutyric acid (GABA) may directly affect GnRH release in the brain of the sea lamprey.

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The Spatial Relationship of γ-Aminobutyric Acid (GABA) Neurons and Gonadotropin-Releasing Hormone (GnRH) Neurons in Larval and Adult Sea Lamprey, <i>Petromyzon marinus</i>

Cited by 22 publications

References 57 publications

Screening and optimization of γ-aminobutyric acid production fromMonascus sanguineusunder solid-state fermentation

Screening and optimization of γ-aminobutyric acid production fromMonascus sanguineusunder solid-state fermentation

Human neurons express type I GnRH receptor and respond to GnRH I by increasing luteinizing hormone expression

In situ Characterization of Gonadotropin- Releasing Hormone-I, -III, and Glutamic Acid Decarboxylase Expression in the Brain of the Sea Lamprey, <i>Petromyzon marinus</i>

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