1
|
Grattan DR. Does the brain make prolactin? J Neuroendocrinol 2024:e13432. [PMID: 39041379 DOI: 10.1111/jne.13432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 06/28/2024] [Accepted: 07/05/2024] [Indexed: 07/24/2024]
Abstract
The prolactin receptor (Prlr) is widely expressed in the brain, particularly in the hypothalamus. Prolactin also has an increasing range of well-characterised effects on central nervous system function. Because of this, over many years, there has been interest in whether the hormone itself is also expressed within the brain, perhaps acting as a neuropeptide to regulate brain function via its receptor in neurons. The aim of this invited review is to critically evaluate the evidence for brain production of prolactin. Unlike the evidence for the Prlr, evidence for brain prolactin is inconsistent and variable. A range of different antibodies have been used, each characterising a different distribution of prolactin-like immunoreactivity. Prolactin mRNA has been detected in the brain, but only at levels markedly lower than seen in the pituitary gland. Importantly, it has largely only been detected by highly sensitive amplification-based techniques, and the extreme sensitivity means there is a risk of false-positive data. Modern in situ hybridisation methods and single-cell RNA sequencing have not provided supporting evidence, but it is hard to prove a negative! Finally, I acknowledge and discuss the possibility that prolactin might be produced in the brain under specific circumstances, such as to promote a neuroprotective response to cell damage. Collectively, however, based on this analysis, I have formed the opinion that brain production of prolactin is unlikely, and even if occurs, it is of little physiological consequence. Most, if not all of the brain actions of prolactin can be explained by pituitary prolactin gaining access to the brain.
Collapse
Affiliation(s)
- David R Grattan
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| |
Collapse
|
2
|
Banks CM, Trott JF, Hovey RC. The prolactin receptor: A cross-species comparison of gene structure, transcriptional regulation, tissue-specificity, and genetic variation. J Neuroendocrinol 2024; 36:e13385. [PMID: 38586906 DOI: 10.1111/jne.13385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 02/25/2024] [Accepted: 03/13/2024] [Indexed: 04/09/2024]
Abstract
The conserved and multifaceted functions of prolactin (PRL) are coordinated through varied distribution and expression of its cell-surface receptor (PRLR) across a range of tissues and physiological states. The resultant heterogeneous expression of PRLR mRNA and protein across different organs and cell types supports a wide range of PRL-regulated processes including reproduction, lactation, development, and homeostasis. Genetic variation within the PRLR gene also accounts for several phenotypes impacting agricultural production and human pathology. The goal of this review is to highlight the many elements that control differential expression of the PRLR across tissues, and the various phenotypes that exist across species due to variation in the PRLR gene.
Collapse
Affiliation(s)
- Carmen M Banks
- Department of Animal Science, University of California, Davis, Davis, California, USA
| | - Josephine F Trott
- Department of Animal Science, University of California, Davis, Davis, California, USA
| | - Russell C Hovey
- Department of Animal Science, University of California, Davis, Davis, California, USA
| |
Collapse
|
3
|
Puska G, Szendi V, Dobolyi A. Lateral septum as a possible regulatory center of maternal behaviors. Neurosci Biobehav Rev 2024; 161:105683. [PMID: 38649125 DOI: 10.1016/j.neubiorev.2024.105683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 04/09/2024] [Accepted: 04/17/2024] [Indexed: 04/25/2024]
Abstract
The lateral septum (LS) is involved in controlling anxiety, aggression, feeding, and other motivated behaviors. Lesion studies have also implicated the LS in various forms of caring behaviors. Recently, novel experimental tools have provided a more detailed insight into the function of the LS, including the specific role of distinct cell types and their neuronal connections in behavioral regulations, in which the LS participates. This article discusses the regulation of different types of maternal behavioral alterations using the distributions of established maternal hormones such as prolactin, estrogens, and the neuropeptide oxytocin. It also considers the distribution of neurons activated in mothers in response to pups and other maternal activities, as well as gene expressional alterations in the maternal LS. Finally, this paper proposes further research directions to keep up with the rapidly developing knowledge on maternal behavioral control in other maternal brain regions.
Collapse
Affiliation(s)
- Gina Puska
- Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary; Department of Zoology, University of Veterinary Medicine Budapest, Budapest, Hungary
| | - Vivien Szendi
- Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary
| | - Arpád Dobolyi
- Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary; Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary.
| |
Collapse
|
4
|
Hochgerner H, Singh S, Tibi M, Lin Z, Skarbianskis N, Admati I, Ophir O, Reinhardt N, Netser S, Wagner S, Zeisel A. Neuronal types in the mouse amygdala and their transcriptional response to fear conditioning. Nat Neurosci 2023; 26:2237-2249. [PMID: 37884748 PMCID: PMC10689239 DOI: 10.1038/s41593-023-01469-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/20/2023] [Indexed: 10/28/2023]
Abstract
The amygdala is a brain region primarily associated with emotional response. The use of genetic markers and single-cell transcriptomics can provide insights into behavior-associated cell state changes. Here we present a detailed cell-type taxonomy of the adult mouse amygdala during fear learning and memory consolidation. We perform single-cell RNA sequencing on naïve and fear-conditioned mice, identify 130 neuronal cell types and validate their spatial distributions. A subset of all neuronal types is transcriptionally responsive to fear learning and memory retrieval. The activated engram cells upregulate activity-response genes and coordinate the expression of genes associated with neurite outgrowth, synaptic signaling, plasticity and development. We identify known and previously undescribed candidate genes responsive to fear learning. Our molecular atlas may be used to generate hypotheses to unveil the neuron types and neural circuits regulating the emotional component of learning and memory.
Collapse
Affiliation(s)
- Hannah Hochgerner
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Shelly Singh
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Muhammad Tibi
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Zhige Lin
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Niv Skarbianskis
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Inbal Admati
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Osnat Ophir
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Nuphar Reinhardt
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Shai Netser
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Shlomo Wagner
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Amit Zeisel
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel.
| |
Collapse
|
5
|
Carretero-Hernández M, Catalano-Iniesta L, Blanco EJ, García-Barrado MJ, Carretero J. Highlights regarding prolactin in the dentate gyrus and hippocampus. VITAMINS AND HORMONES 2022; 118:479-505. [PMID: 35180938 DOI: 10.1016/bs.vh.2021.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Prolactin (PRL) is a pituitary hormone that has been typically related to lactogenesis in mammals. However, it has been described over 300 roles in the organism of vertebrae and its relationship with the central nervous system (CNS) is yet to be clarified. Mainly secreted by the pituitary gland, the source of prolactin in the CNS remains unclear, where some experiments suggest active transport via an unknown carrier or, on the contrary, PRL being synthesized on the brain. So far, it seems to be involved with neurogenesis, neuroprotection, maternal behavior and cognitive processes in the hippocampus and dentate gyrus, among other regions.
Collapse
Affiliation(s)
- Marta Carretero-Hernández
- Department of Human Anatomy and Histology, Faculty of Medicine, University of Salamanca, Spain; Laboratory of Neuroendocrinology, Institute of Neurosciences of Castilla y León (INCyL), and Laboratory of Neuroendocrinology and Obesity, Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Spain.
| | - Leonardo Catalano-Iniesta
- Department of Human Anatomy and Histology, Faculty of Medicine, University of Salamanca, Spain; Laboratory of Neuroendocrinology, Institute of Neurosciences of Castilla y León (INCyL), and Laboratory of Neuroendocrinology and Obesity, Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Spain
| | - Enrique J Blanco
- Department of Human Anatomy and Histology, Faculty of Medicine, University of Salamanca, Spain; Laboratory of Neuroendocrinology, Institute of Neurosciences of Castilla y León (INCyL), and Laboratory of Neuroendocrinology and Obesity, Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Spain
| | - María José García-Barrado
- Laboratory of Neuroendocrinology, Institute of Neurosciences of Castilla y León (INCyL), and Laboratory of Neuroendocrinology and Obesity, Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Spain; Department of Physiology and Pharmacology, Faculty of Medicine, University of Salamanca, Spain
| | - José Carretero
- Department of Human Anatomy and Histology, Faculty of Medicine, University of Salamanca, Spain; Laboratory of Neuroendocrinology, Institute of Neurosciences of Castilla y León (INCyL), and Laboratory of Neuroendocrinology and Obesity, Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Spain
| |
Collapse
|
6
|
Costa-Brito AR, Gonçalves I, Santos CRA. The brain as a source and a target of prolactin in mammals. Neural Regen Res 2022; 17:1695-1702. [PMID: 35017416 PMCID: PMC8820687 DOI: 10.4103/1673-5374.332124] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Prolactin is a polypeptide hormone associated with an extensive variety of biological functions. Among the roles of prolactin in vertebrates, some were preserved throughout evolution. This is the case of its function in the brain, where prolactin receptors, are expressed in different structures of the central nervous system. In the brain, prolactin actions are principally associated with reproduction and parental behavior, and involves the modulation of adult neurogenesis, neuroprotection, and neuroplasticity, especially during pregnancy, thereby preparing the brain to parenthood. Prolactin is mainly produced by specialized cells in the anterior pituitary gland. However, during vertebrate evolution many other extrapituitary tissues do also produce prolactin, like the immune system, endothelial cells, reproductive structures and in several regions of the brain. This review summarizes the relevance of prolactin for brain function, the sources of prolactin in the central nervous system, as well as its local production and secretion. A highlight on the impact of prolactin in human neurological diseases is also provided.
Collapse
Affiliation(s)
- Ana R Costa-Brito
- CICS-UBI - Health Sciences Research Centre, Universidade da Beira Interior, Covilhã, Portugal
| | - Isabel Gonçalves
- CICS-UBI - Health Sciences Research Centre; C4-UBI -Cloud Computing Competence Centre, Universidade da Beira Interior, Covilhã, Portugal
| | - Cecília R A Santos
- CICS-UBI - Health Sciences Research Centre; C4-UBI -Cloud Computing Competence Centre, Universidade da Beira Interior, Covilhã, Portugal
| |
Collapse
|
7
|
Georgescu T, Swart JM, Grattan DR, Brown RSE. The Prolactin Family of Hormones as Regulators of Maternal Mood and Behavior. Front Glob Womens Health 2021; 2:767467. [PMID: 34927138 PMCID: PMC8673487 DOI: 10.3389/fgwh.2021.767467] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/01/2021] [Indexed: 12/30/2022] Open
Abstract
Transition into motherhood involves profound physiological and behavioral adaptations that ensure the healthy development of offspring while maintaining maternal health. Dynamic fluctuations in key hormones during pregnancy and lactation induce these maternal adaptations by acting on neural circuits in the brain. Amongst these hormonal changes, lactogenic hormones (e.g., prolactin and its pregnancy-specific homolog, placental lactogen) are important regulators of these processes, and their receptors are located in key brain regions controlling emotional behaviors and maternal responses. With pregnancy and lactation also being associated with a marked elevation in the risk of developing mood disorders, it is important to understand how hormones are normally regulating mood and behavior during this time. It seems likely that pathological changes in mood could result from aberrant expression of these hormone-induced behavioral responses. Maternal mental health problems during pregnancy and the postpartum period represent a major barrier in developing healthy mother-infant interactions which are crucial for the child's development. In this review, we will examine the role lactogenic hormones play in driving a range of specific maternal behaviors, including motivation, protectiveness, and mother-pup interactions. Understanding how these hormones collectively act in a mother's brain to promote nurturing behaviors toward offspring will ultimately assist in treatment development and contribute to safeguarding a successful pregnancy.
Collapse
Affiliation(s)
- Teodora Georgescu
- Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Judith M. Swart
- Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - David R. Grattan
- Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Rosemary S. E. Brown
- Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| |
Collapse
|
8
|
Decoding signaling pathways involved in prolactin-induced neuroprotection: A review. Front Neuroendocrinol 2021; 61:100913. [PMID: 33766566 DOI: 10.1016/j.yfrne.2021.100913] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 03/11/2021] [Accepted: 03/13/2021] [Indexed: 11/23/2022]
Abstract
It has been well recognized that prolactin (PRL), a pleiotropic hormone, has many functions in the brain, such as maternal behavior, neurogenesis, and neuronal plasticity, among others. Recently, it has been reported to have a significant role in neuroprotection against excitotoxicity. Glutamate excitotoxicity is a common alteration in many neurological and neurodegenerative diseases, leading to neuronal death. In this sense, several efforts have been made to decrease the progression of these pathologies. Despite various reports of PRL's neuroprotective effect against excitotoxicity, the signaling pathways that underlie this mechanism remain unclear. This review aims to describe the most recent and relevant studies on the molecular signaling pathways, particularly, PI3K/AKT, NF-κB, and JAK2/STAT5, which are currently under investigation and might be implicated in the molecular mechanisms that explain the PRL effects against excitotoxicity and neuroprotection. Remarkable neuroprotective effects of PRL might be useful in the treatment of some neurological diseases.
Collapse
|
9
|
Orazov MR, Mikhaleva LM, Samarina EA, Semenov PA. An Overview on the Role of Prolactin and its Receptors in the Reproductive System of Women with External Genital Endometriosis. ACTA ACUST UNITED AC 2020. [DOI: 10.18499/2225-7357-2020-9-2-84-89] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- M. R. Orazov
- Peoples’ Friendship University of Russia, Moscow
| | | | | | | |
Collapse
|
10
|
Dobolyi A, Oláh S, Keller D, Kumari R, Fazekas EA, Csikós V, Renner É, Cservenák M. Secretion and Function of Pituitary Prolactin in Evolutionary Perspective. Front Neurosci 2020; 14:621. [PMID: 32612510 PMCID: PMC7308720 DOI: 10.3389/fnins.2020.00621] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 05/19/2020] [Indexed: 12/16/2022] Open
Abstract
The hypothalamo-pituitary system developed in early vertebrates. Prolactin is an ancient vertebrate hormone released from the pituitary that exerts particularly diverse functions. The purpose of the review is to take a comparative approach in the description of prolactin, its secretion from pituitary lactotrophs, and hormonal functions. Since the reproductive and osmoregulatory roles of prolactin are best established in a variety of species, these functions are the primary subjects of discussion. Different types of prolactin and prolactin receptors developed during vertebrate evolution, which will be described in this review. The signal transduction of prolactin receptors is well conserved among vertebrates enabling us to describe the whole subphylum. Then, the review focuses on the regulation of prolactin release in mammals as we have the most knowledge on this class of vertebrates. Prolactin secretion in response to different reproductive stimuli, such as estrogen-induced release, mating, pregnancy and suckling is detailed. Reproduction in birds is different from that in mammals in several aspects. Prolactin is released during incubation in avian species whose regulation and functional significance are discussed. Little information is available on prolactin in reptiles and amphibians; therefore, they are mentioned only in specific cases to explain certain evolutionary aspects. In turn, the osmoregulatory function of prolactin is well established in fish. The different types of pituitary prolactin in fish play particularly important roles in the adaptation of eutherian species to fresh water environments. To achieve this function, prolactin is released from lactotrophs in hyposmolarity, as they are directly osmosensitive in fish. In turn, the released prolactin acts on branchial epithelia, especially ionocytes of the gill to retain salt and excrete water. This review will highlight the points where comparative data give new ideas or suggest new approaches for investigation in other taxa.
Collapse
Affiliation(s)
- Arpád Dobolyi
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
- Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Szilvia Oláh
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - Dávid Keller
- Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Rashmi Kumari
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - Emese A. Fazekas
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - Vivien Csikós
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - Éva Renner
- Human Brain Tissue Bank and Microdissection Laboratory, Semmelweis University, Budapest, Hungary
| | - Melinda Cservenák
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| |
Collapse
|
11
|
Salais-López H, Agustín-Pavón C, Lanuza E, Martínez-García F. The maternal hormone in the male brain: Sexually dimorphic distribution of prolactin signalling in the mouse brain. PLoS One 2018; 13:e0208960. [PMID: 30571750 PMCID: PMC6301622 DOI: 10.1371/journal.pone.0208960] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/27/2018] [Indexed: 01/10/2023] Open
Abstract
Research of the central actions of prolactin is highly focused on females, but this hormone has also documented roles in male physiology and behaviour. Here, we provide the first description of the pattern of prolactin-derived signalling in the male mouse brain, employing the immunostaining of phosphorylated signal transducer and activator of transcription 5 (pSTAT5) after exogenous prolactin administration. Next, we explore possible sexually dimorphic differences by comparing pSTAT5 immunoreactivity in prolactin-supplemented males and females. We also assess the role of testosterone in the regulation of central prolactin signalling in males by comparing intact with castrated prolactin-supplemented males. Prolactin-supplemented males displayed a widespread pattern of pSTAT5 immunoreactivity, restricted to brain centres showing expression of the prolactin receptor. Immunoreactivity for pSTAT5 was present in several nuclei of the preoptic, anterior and tuberal hypothalamus, as well as in the septofimbrial nucleus or posterodorsal medial amygdala of the telencephalon. Conversely, non-supplemented control males were virtually devoid of pSTAT5-immunoreactivity, suggesting that central prolactin actions in males are limited to situations concurrent with substantial hypophyseal prolactin release (e.g. stress or mating). Furthermore, comparison of prolactin-supplemented males and females revealed a significant, female-biased sexual dimorphism, supporting the view that prolactin has a preeminent role in female physiology and behaviour. Finally, in males, castration significantly reduced pSTAT5 immunoreactivity in some structures, including the paraventricular and ventromedial hypothalamic nuclei and the septofimbrial region, thus indicating a region-specific regulatory role of testosterone over central prolactin signalling.
Collapse
Affiliation(s)
- Hugo Salais-López
- Unitat Predepartamental de Medicina, Facultat de Ciències de la Salut, Universitat Jaume I, Castelló de la Plana, Spain
| | - Carmen Agustín-Pavón
- Unitat Predepartamental de Medicina, Facultat de Ciències de la Salut, Universitat Jaume I, Castelló de la Plana, Spain
- Departament de Biologia Cel·lular i de Biologia Funcional, Facultat de Ciències Biològiques, Universitat de València, València, Spain
| | - Enrique Lanuza
- Departament de Biologia Cel·lular i de Biologia Funcional, Facultat de Ciències Biològiques, Universitat de València, València, Spain
| | - Fernando Martínez-García
- Unitat Predepartamental de Medicina, Facultat de Ciències de la Salut, Universitat Jaume I, Castelló de la Plana, Spain
| |
Collapse
|
12
|
Ma S, Li D, Jiang J, Shen B. Role of the Medial Preoptic Area in Electroacupuncture Treatment of Reproductive Dysfunction in Ovariectomised Rats. Acupunct Med 2018; 35:52-58. [DOI: 10.1136/acupmed-2015-010839] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2016] [Indexed: 11/04/2022]
Abstract
Objective To investigate the role of the medial preoptic area (MPOA) of the hypothalamus in electroacupuncture (EA) treatment of reproductive dysfunction in ovariectomised (OVX) rats and to examine the underlying mechanisms of action. Methods 62 female Sprague-Dawley rats (200–220 g) underwent bilateral ovariectomy (OVX). Three weeks later, 32 rats assigned to experiment 1 were randomly divided into four groups: two groups underwent MPOA lesioning (n=16) followed by EA at CV4, CV3, SP6 and bilateral Zigong (30 min per day) for 3 days (OVX+MPOA+EA group, n=8) or no treatment (OVX+MPOA group, n=8); and two groups underwent sham (S) surgery (n=16) followed by EA (OVX+SMPOA+EA group, n=8) or no treatment (OVX+SMPOA group, n=8). Plasma oestradiol and luteinising hormone (LH) were measured by radioimmunoassay and mature vaginal epithelial cells stained and quantified post-treatment. 30 rats assigned to experiment 2 were randomised to receive EA (OVX+EA group, n=15) or remain untreated (OVX group, n=15), following which push-pull perfusion in combination with high pressure liquid chromatography/electrochemical (HPLC-EC) detection was used to measure neurotransmitter release in the MPOA. Results EA significantly increased the percentage of mature vaginal epithelial cells and plasma oestradiol levels in sham MPOA-lesioned rats compared with MPOA-lesioned OVX rats (p<0.05). In sham MPOA-lesioned OVX rats, EA significantly decreased plasma LH levels compared with no treatment (p<0.01). HPLC-EC results showed that γ-aminobutyric acid (GABA) and β-endorphin levels in the MPAO were significantly increased in OVX rats following EA (p<0.01). Conclusions The present study suggests that the MPOA plays a crucial role in EA treatment of abnormal reproductive function in OVX rats.
Collapse
Affiliation(s)
- Shulan Ma
- Training Center of Medical Experiments, Basic Medical School, Fudan University, Shanghai, China
- Department of Integrative Medicine and Neurobiology, State Key Lab of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Dongju Li
- Training Center of Medical Experiments, Basic Medical School, Fudan University, Shanghai, China
| | - Jianwei Jiang
- Department of Integrative Medicine and Neurobiology, State Key Lab of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Bo Shen
- Institute of Radiation Medicine, Fudan University, Shanghai, China
| |
Collapse
|
13
|
Voigt C, Bennett N. Reproductive status affects the expression of prolactin receptor mRNA in the brain of female Damaraland mole-rats. J Chem Neuroanat 2018; 94:1-7. [DOI: 10.1016/j.jchemneu.2018.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/12/2018] [Accepted: 08/13/2018] [Indexed: 01/25/2023]
|
14
|
Cabrera-Reyes EA, Limón-Morales O, Rivero-Segura NA, Camacho-Arroyo I, Cerbón M. Prolactin function and putative expression in the brain. Endocrine 2017. [PMID: 28634745 DOI: 10.1007/s12020-017-1346-x] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
INTRODUCTION Prolactin is a peptide hormone mainly synthetized and secreted by the anterior pituitary gland, but also by extrapituitary tissues, such as mammary gland, decidua, prostate, skin, and possibly the brain. Similarly, prolactin receptor is expressed in the pituitary gland, many peripheral tissues, and in contrast to prolactin, its receptor has been consistently detected in several brain regions, such as cerebral cortex, olfactory bulb, hypothalamus, hippocampus, amygdala, among others. Classically, prolactin function has been related to the stimulation of lactogenesis and galactopoiesis, however, it is well known that prolactin induces a wide range of functions in different brain areas. PURPOSE The aim of this review is to summarize recent reports on prolactin and prolactin receptor synthesis and localization, as well as recapitulate both the classic functions attributed to this hormone in the brain and the recently described functions such as neurogenesis, neurodevelopment, sleep, learning and memory, and neuroprotection. CONCLUSION The distribution and putative expression of prolactin and its receptors in several neuronal tissues suggests that this hormone has pleiotropic functions in the brain.
Collapse
Affiliation(s)
- Erika Alejandra Cabrera-Reyes
- Unidad de Investigación en Reproducción Humana Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México. CDMX, Mexico, Mexico
| | - Ofelia Limón-Morales
- Unidad de Investigación en Reproducción Humana Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México. CDMX, Mexico, Mexico
| | - Nadia Alejandra Rivero-Segura
- Unidad de Investigación en Reproducción Humana Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México. CDMX, Mexico, Mexico
| | - Ignacio Camacho-Arroyo
- Unidad de Investigación en Reproducción Humana Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México. CDMX, Mexico, Mexico
| | - Marco Cerbón
- Unidad de Investigación en Reproducción Humana Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México. CDMX, Mexico, Mexico.
| |
Collapse
|
15
|
Gustafson P, Kokay I, Sapsford T, Bunn S, Grattan D. Prolactin regulation of the HPA axis is not mediated by a direct action upon CRH neurons: evidence from the rat and mouse. Brain Struct Funct 2017; 222:3191-3204. [DOI: 10.1007/s00429-017-1395-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/24/2017] [Indexed: 10/19/2022]
|
16
|
Al-Kuraishy HM, Al-Gareeb AI, Awad MS, Alrifai SB. Assessment of serum prolactin levels in acute myocardial infarction: The role of pharmacotherapy. Indian J Endocrinol Metab 2016; 20:72-79. [PMID: 26904472 PMCID: PMC4743388 DOI: 10.4103/2230-8210.172240] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Hyperprolactinemia may reflect neuroendocrine stress reaction against acute coronary syndromes. AIM The aim of the present study was evaluation of the serum prolactin level in the acute myocardial infarction (MI) regarding the current pharmacotherapy in management of MI. SETTING AND DESIGN Cross-sectional clinical based study. SUBJECTS AND METHODS This cross-sectional clinical study involved all patients with acute MI in a coronary care unit, a total number of 44 patients (45% males and 55% females) with age ranged from 40 to 75 years. A full history for modifiable risk factors and current therapy with aspirin, clopidogrel and or metformin, all patients are nonsmokers. The anthropometric measurements; for estimations of body mass index (kg/m(2)), electrocardiography was obtained. Fasting blood samples were taken in the morning from all patients and the sera used for estimations of routine investigation and determination of ischemic cardiac biomarkers like cardiac troponin I (cTnI) and serum prolactin level. RESULTS This study shows a significant increase in the serum prolactin in acute MI as compared with the control. In acute MI serum cTnI elevation was correlated with serum prolactin increments. In metformin-treated group, there was a lowest prolactin serum level. CONCLUSIONS Serum prolactin level increased in acute MI, and positively correlated with cardiac troponin level and reflects underlying cardiovascular complications.
Collapse
Affiliation(s)
- Hayder M. Al-Kuraishy
- Department of Pharmacology, Toxicology and Medicine, College of Medicine, Al-Mustansiriya University, Baghdad, Iraq
| | - Ali I. Al-Gareeb
- Department of Pharmacology, Toxicology and Medicine, College of Medicine, Al-Mustansiriya University, Baghdad, Iraq
| | - Mohamed S. Awad
- Department of Pharmacology, Toxicology and Medicine, College of Medicine, Al-Mustansiriya University, Baghdad, Iraq
| | - Sinan B. Alrifai
- Department of Pharmacology, Toxicology and Medicine, College of Medicine, Al-Mustansiriya University, Baghdad, Iraq
| |
Collapse
|
17
|
Brown RSE, Wyatt AK, Herbison RE, Knowles PJ, Ladyman SR, Binart N, Banks WA, Grattan DR. Prolactin transport into mouse brain is independent of prolactin receptor. FASEB J 2015; 30:1002-10. [DOI: 10.1096/fj.15-276519] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 10/28/2015] [Indexed: 12/27/2022]
Affiliation(s)
- Rosemary S. E. Brown
- Centre for NeurendocrinologyUniversity of OtagoDunedinNew Zealand
- Department of AnatomyOtago School of Medical SciencesUniversity of OtagoDunedinNew Zealand
| | - Amanda K. Wyatt
- Centre for NeurendocrinologyUniversity of OtagoDunedinNew Zealand
- Department of AnatomyOtago School of Medical SciencesUniversity of OtagoDunedinNew Zealand
| | - Ryan E. Herbison
- Centre for NeurendocrinologyUniversity of OtagoDunedinNew Zealand
- Department of AnatomyOtago School of Medical SciencesUniversity of OtagoDunedinNew Zealand
| | - Penelope J. Knowles
- Centre for NeurendocrinologyUniversity of OtagoDunedinNew Zealand
- Department of AnatomyOtago School of Medical SciencesUniversity of OtagoDunedinNew Zealand
| | - Sharon R. Ladyman
- Centre for NeurendocrinologyUniversity of OtagoDunedinNew Zealand
- Department of AnatomyOtago School of Medical SciencesUniversity of OtagoDunedinNew Zealand
| | - Nadine Binart
- INSERM U1185Faculté de Médecine Paris SudLe Kremlin‐BicêtreFrance
| | - William A. Banks
- Geriatrics Research Education and Clinical CenterVeterans Affairs Puget Sound Health Care CenterSeattleWashingtonUSA
- Division of Gerontology and Geriatric MedicineDepartment of MedicineUniversity of Washington School of MedicineSeattleWashingtonUSA
| | - David R. Grattan
- Centre for NeurendocrinologyUniversity of OtagoDunedinNew Zealand
- Department of AnatomyOtago School of Medical SciencesUniversity of OtagoDunedinNew Zealand
| |
Collapse
|
18
|
Patil MJ, Henry MA, Akopian AN. Prolactin receptor in regulation of neuronal excitability and channels. Channels (Austin) 2015; 8:193-202. [PMID: 24758841 DOI: 10.4161/chan.28946] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Prolactin (PRL) activates PRL receptor isoforms to exert regulation of specific neuronal circuitries, and to control numerous physiological and clinically-relevant functions including; maternal behavior, energy balance and food intake, stress and trauma responses, anxiety, neurogenesis, migraine and pain. PRL controls these critical functions by regulating receptor potential thresholds, neuronal excitability and/or neurotransmission efficiency. PRL also influences neuronal functions via activation of certain neurons, resulting in Ca(2+) influx and/or electrical firing with subsequent release of neurotransmitters. Although PRL was identified almost a century ago, very little specific information is known about how PRL regulates neuronal functions. Nevertheless, important initial steps have recently been made including the identification of PRL-induced transient signaling pathways in neurons and the modulation of neuronal transient receptor potential (TRP) and Ca(2+) -dependent K(+) channels by PRL. In this review, we summarize current knowledge and recent progress in understanding the regulation of neuronal excitability and channels by PRL.
Collapse
|
19
|
Dobolyi A, Grattan DR, Stolzenberg DS. Preoptic inputs and mechanisms that regulate maternal responsiveness. J Neuroendocrinol 2014; 26:627-40. [PMID: 25059569 DOI: 10.1111/jne.12185] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 07/21/2014] [Accepted: 07/22/2014] [Indexed: 12/16/2022]
Abstract
The preoptic area is a well-established centre for the control of maternal behaviour. An intact medial preoptic area (mPOA) is required for maternal responsiveness because lesion of the area abolishes maternal behaviours. Although hormonal changes in the peripartum period contribute to the initiation of maternal responsiveness, inputs from pups are required for its maintenance. Neurones are activated in different parts of the mPOA in response to pup exposure. In the present review, we summarise the potential inputs to the mPOA of rodent dams from the litter that can activate mPOA neurones. The roles of potential indirect effects through increased prolactin levels, as well as neuronal inputs to the preoptic area, are described. Recent results on the pathway mediating the effects of suckling to the mPOA suggest that neurones containing the neuropeptide tuberoinfundibular peptide of 39 residues in the posterior thalamus are candidates for conveying the suckling information to the mPOA. Although the molecular mechanism through which these inputs alter mPOA neurones to support the maintenance of maternal responding is not yet known, altered gene expression is a likely candidate. Here, we summarise gene expression changes in the mPOA that have been linked to maternal behaviour and explore the idea that chromatin remodelling during mother-infant interactions mediates the long-term alterations in gene expression that sustain maternal responding.
Collapse
Affiliation(s)
- A Dobolyi
- Laboratory of Molecular and Systems Neurobiology, Institute of Biology, NAP-Hungarian Academy of Sciences and Eötvös Loránd University, Budapest, Hungary; Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | | | | |
Collapse
|
20
|
Belugin S, Diogenes AR, Patil MJ, Ginsburg E, Henry MA, Akopian AN. Mechanisms of transient signaling via short and long prolactin receptor isoforms in female and male sensory neurons. J Biol Chem 2013; 288:34943-55. [PMID: 24142695 PMCID: PMC3843105 DOI: 10.1074/jbc.m113.486571] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 10/09/2013] [Indexed: 01/01/2023] Open
Abstract
Prolactin (PRL) regulates activity of nociceptors and causes hyperalgesia in pain conditions. PRL enhances nociceptive responses by rapidly modulating channels in nociceptors. The molecular mechanisms underlying PRL-induced transient signaling in neurons are not well understood. Here we use a variety of cell biology and pharmacological approaches to show that PRL transiently enhanced capsaicin-evoked responses involve protein kinase C ε (PKCε) or phosphatidylinositol 3-kinase (PI3K) pathways in female rat trigeminal (TG) neurons. We next reconstituted PRL-induced signaling in a heterologous expression system and TG neurons from PRL receptor (PRLR)-null mutant mice by expressing rat PRLR-long isoform (PRLR-L), PRLR-short isoform (PRLR-S), or a mix of both. Results show that PRLR-S, but not PRLR-L, is capable of mediating PRL-induced transient enhancement of capsaicin responses in both male and female TG neurons. However, co-expression of PRLR-L with PRLR-S (1:1 ratio) leads to the inhibition of the transient PRL actions. Co-expression of PRLR-L deletion mutants with PRLR-S indicated that the cytoplasmic site adjacent to the trans-membrane domain of PRLR-L was responsible for inhibitory effects of PRLR-L. Furthermore, in situ hybridization and immunohistochemistry data indicate that in normal conditions, PRLR-L is expressed mainly in glia with little expression in rat sensory neurons (3-5%) and human nerves. The predominant PRLR form in TG neurons/nerves from rats and humans is PRLR-S. Altogether, PRL-induced transient signaling in sensory neurons is governed by PI3K or PKCε, mediated via the PRLR-S isoform, and transient effects mediated by PRLR-S are inhibited by presence of PRLR-L in these cells.
Collapse
Affiliation(s)
| | | | - Mayur J. Patil
- Pharmacology, University of Texas Health Science Center, San Antonio, Texas 78229 and
| | - Erika Ginsburg
- the NCI, National Institutes of Health, Bethesda, Maryland 20892
| | | | - Armen N. Akopian
- From the Departments of Endodontics and
- Pharmacology, University of Texas Health Science Center, San Antonio, Texas 78229 and
| |
Collapse
|
21
|
Sapsford TJ, Kokay IC, Ostberg L, Bridges RS, Grattan DR. Differential sensitivity of specific neuronal populations of the rat hypothalamus to prolactin action. J Comp Neurol 2012; 520:1062-77. [PMID: 21953590 DOI: 10.1002/cne.22775] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Prolactin stimulates dopamine release from neuroendocrine dopaminergic (NEDA) neurons in the hypothalamic arcuate nucleus (ARC) to maintain low levels of serum prolactin. Elevated prolactin levels during pregnancy and lactation may mediate actions in other hypothalamic regions such as the paraventricular nucleus (PVN) and rostral preoptic area (rPOA). We predicted that NEDA neurons would be more sensitive prolactin targets than neurons in other regions because they are required to regulate basal prolactin secretion. Moreover, differences in the accessibility of the ARC to prolactin in blood may influence the responsiveness of this population. Therefore, we compared prolactin-induced signaling in different hypothalamic neuronal populations following either systemic or intracerebroventricular (icv) prolactin administration. Phosphorylation of the signal transduction factor, STAT5 (pSTAT5), was used to identify prolactin-responsive neurons. In response to systemic prolactin, pSTAT5-labeled cells were widely observed in the ARC but absent from the rPOA and PVN. Many of these responsive cells in the ARC were identified as NEDA neurons. The lowest icv prolactin dose (10 ng) induced pSTAT5 in the ARC, but with higher doses (>500 ng) pSTAT5 was detected in numerous regions, including the rPOA and PVN. NEDA neurons were maximally labeled with nuclear pSTAT5 in response to 500 ng prolactin and appeared to be more sensitive than dopaminergic neurons in the rPOA. Subpopulations of oxytocin neurons in the hypothalamus were also found to be differentially sensitive to prolactin. These data suggest that differences in the accessibility of the arcuate nucleus to prolactin, together with intrinsic differences in the NEDA neurons, may facilitate homeostatic feedback regulation of prolactin release.
Collapse
Affiliation(s)
- Tony J Sapsford
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago, Dunedin, New Zealand
| | | | | | | | | |
Collapse
|
22
|
Brown RSE, Piet R, Herbison AE, Grattan DR. Differential actions of prolactin on electrical activity and intracellular signal transduction in hypothalamic neurons. Endocrinology 2012; 153:2375-84. [PMID: 22416085 DOI: 10.1210/en.2011-2005] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In many tissues, including brain, prolactin action is predominantly mediated by the Janus kinase/signal transducer and activator of transcription (STAT) signal transduction pathway, leading to changes in gene transcription. However, prolactin can also exert rapid actions on electrical activity of hypothalamic neurons. Here, we investigate whether both responses occur in a single cell type, focusing on three specific populations known to be influenced by prolactin: GnRH neurons, tuberoinfundibular dopamine (TIDA) neurons, and neurons in the anteroventral-periventricular nucleus in female mice. We performed phosphorylated STAT5 (pSTAT5) immunohistochemistry to identify prolactin-responsive neurons after in vivo prolactin treatment. In addition, we carried out in vitro electrophysiology in slices from transgenic mice expressing green fluorescent protein driven by the GnRH or tyrosine hydroxylase promoters as well as from C57BL/6J mice to assess acute electrical responses to prolactin. Approximately 88% of TIDA neurons expressed pSTAT5 in diestrous mice, rising to 97% after prolactin treatment. All TIDA neurons also showed a rapid increase in firing rate after prolactin treatment. In contrast, very few GnRH neurons (11%) showed pSTAT5 in response to prolactin, and none showed a change in electrical activity. Finally, in the anteroventral-periventricular nucleus, most neurons (69%) responded to prolactin treatment with an increase in pSTAT5, but only 2/38 (∼5%) showed changes in electrical activity in response to prolactin. These observations show that prolactin recruits different combinations of electrical and transcriptional responses in neurons depending upon their anatomical location and phenotype. This may be critical in establishing appropriate responses to prolactin under different physiological conditions.
Collapse
Affiliation(s)
- R S E Brown
- Department of Anatomy, University of Otago, P. O. Box 913, Dunedin 9054, New Zealand
| | | | | | | |
Collapse
|
23
|
Sirzen-Zelenskaya A, Gonzalez-Iglesias AE, de Monvel JB, Bertram R, Freeman ME, Gerber U, Egli M. Prolactin induces a hyperpolarising current in rat paraventricular oxytocinergic neurones. J Neuroendocrinol 2011; 23:883-93. [PMID: 21851427 PMCID: PMC3235712 DOI: 10.1111/j.1365-2826.2011.02207.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Prolactin and oxytocin are important reproductive hormones implicated in several common adaptive functions during pregnancy, pseudopregnancy and lactation. Recently, extracellular recordings of supraoptic neurones have shown that prolactin may modulate the electrical activity of oxytocinergic neurones. However, no study has been conducted aiming to establish whether prolactin directly influences this activity in oxytocinergic paraventricular neurones. In the present study, we addressed this question by studying the effects of prolactin on the electrical activity and voltage-current relationship of identified paraventricular neurones in rat brain slices. Whole-cell recordings were obtained and neurones were classified on the basis of their morphological and electrophysiological fingerprint (i.e. magnocellular or parvicellular) and neuropeptide phenotype (i.e. oxytocinergic or non-oxytocinergic). We report that prolactin elicited a hyperpolarising current in 37% of the neurones in this nucleus, of which the majority (67%) were identified as putative magnocellular oxytocin neurones and the reminder (33%) were regarded as oxytocin-negative, parvicellular neuroendocrine neurones. Our results suggest that, in addition to the well-established negative feedback loop between prolactin-secreting lactotrophs and dopaminergic neurones in the arcuate nucleus, an inhibitory feedback loop also exists between lactotrophs and oxytocinergic paraventricular neurones.
Collapse
Affiliation(s)
| | | | | | - Richard Bertram
- Department of Mathematics and Programs in Neuroscience and Molecular Biophysics, Florida State University, Tallahassee, FL
| | - Marc E. Freeman
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, FL
| | - Urs Gerber
- Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Marcel Egli
- Space Biology Group, ETH Zurich, Switzerland
| |
Collapse
|
24
|
Sjoeholm A, Bridges RS, Grattan DR, Anderson GM. Region-, neuron-, and signaling pathway-specific increases in prolactin responsiveness in reproductively experienced female rats. Endocrinology 2011; 152:1979-88. [PMID: 21363933 PMCID: PMC3075931 DOI: 10.1210/en.2010-1220] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pregnancy and lactation cause long-lasting enhancements in maternal behavior and other physiological functions, along with increased hypothalamic prolactin receptor expression. To directly test whether reproductive experience increases prolactin responsiveness in the arcuate, paraventricular, and supraoptic nuclei and the medial preoptic area, female rats experienced a full pregnancy and lactation or remained as age-matched virgin controls. At 5 wk after weaning, rats received 2.5, 100, or 4000 ng ovine prolactin or vehicle intracerebroventricularly. The brains underwent immunohistochemistry for the phosphorylated forms of signal transducer and activator of transcription 5 (pSTAT5) or ERK1/2 (pERK1/2). There was a marked increase in pSTAT5 and pERK1/2 in response to prolactin in the regions examined in both virgin and primiparous rats. Primiparous rats exhibited approximately double the number of prolactin-induced pSTAT5-immunoreactive cells as virgins, this effect being most apparent at the higher prolactin doses in the medial preoptic area and paraventricular and supraoptic nuclei and at the lowest prolactin dose in the arcuate nucleus. Dual-label immunohistochemistry showed that arcuate kisspeptin (but not oxytocin or dopamine) neurons displayed increased sensitivity to prolactin in reproductively experienced animals; these neurons may contribute to the reduction in prolactin concentration observed after reproductive experience. There was no effect of reproductive experience on prolactin-induced pERK1/2, indicating a selective effect on the STAT5 pathway. These data show that STAT5 responsiveness to prolactin is enhanced by reproductive experience in multiple hypothalamic regions. The findings may have significant implications for understanding postpartum disorders affecting maternal care and other prolactin-associated pathologies.
Collapse
Affiliation(s)
- Annika Sjoeholm
- Centre for Neuroendocrinology and Department of Anatomy and Structural Biology, University of Otago School of Medical Sciences, Dunedin, New Zealand
| | | | | | | |
Collapse
|
25
|
van den Burg EH, Neumann ID. Bridging the gap between GPCR activation and behaviour: oxytocin and prolactin signalling in the hypothalamus. J Mol Neurosci 2010; 43:200-8. [PMID: 20865346 DOI: 10.1007/s12031-010-9452-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Accepted: 09/13/2010] [Indexed: 01/06/2023]
Abstract
Neuropeptides of the brain are important neuromodulators, controlling behaviour and physiology. They signal through G protein-coupled receptors (GPCR) that couple to complex intracellular signalling pathways. These signalling networks integrate information from multiple sources, resulting in appropriate physiological and behavioural responses to environmental and internal cues. This paper will focus on the neuropeptides oxytocin and prolactin with respect to (1) the regulation of neuroendocrine stress responses and anxiety, and (2) the receptor-mediated molecular mechanisms underlying these actions of the neuropeptides. Besides its significant reproductive functions when released into the bloodstream, brain oxytocin reduces the activity of the hypothalamo-pituitary-adrenal (HPA) axis as well as anxiety-related behaviour in male and female rats. Oxytocin mediates its anxiolytic effect, at least in part, via binding to its GPCR in the hypothalamic paraventricular nucleus, followed by transactivation of the epidermal growth factor receptor, and subsequent activation of a MEK-extracellular signal-regulated kinase (ERK) MAP kinase pathway. Prolactin, by binding to its GPCR receptors, of which there are short and long forms, also activates ERK, and this is necessary for the control of the expression of corticotrophin-releasing hormone-an important regulator of the HPA axis. Liganded oxytocin and prolactin may also recruit other signalling pathways, but how these pathways contribute to the observed behavioural and physiological effects remains to be established. GPCR-mediated oxytocin and prolactin neuronal signalling are illustrative of the complexity of GPCR-activated regulation of appropriate neuroendocrine and behavioural responses to environmental and physiological demands.
Collapse
Affiliation(s)
- Erwin H van den Burg
- Behavioural and Molecular Neuroendocrinology, Institute of Zoology, University of Regensburg, 93053 Regensburg, Germany.
| | | |
Collapse
|
26
|
Brown RS, Kokay IC, Herbison AE, Grattan DR. Distribution of prolactin-responsive neurons in the mouse forebrain. J Comp Neurol 2010; 518:92-102. [DOI: 10.1002/cne.22208] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
27
|
Blume A, Torner L, Liu Y, Subburaju S, Aguilera G, Neumann ID. Prolactin induces Egr-1 gene expression in cultured hypothalamic cells and in the rat hypothalamus. Brain Res 2009; 1302:34-41. [PMID: 19769948 DOI: 10.1016/j.brainres.2009.09.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 09/01/2009] [Accepted: 09/12/2009] [Indexed: 11/25/2022]
Abstract
Prolactin (PRL), the major lactogenic hormone, acts also as neuromodulator and regulator of neuronal and glial plasticity in the brain. There is an increase in synthesis and release of PRL within the hypothalamus during peripartum and in response to stress. To identify mechanisms by which PRL induces neuroplasticity, we studied the ability of PRL to induce the transcription factor Egr-1 in the hypothalamic cell line, 4B, in vitro, and in specific neuronal cell types of the hypothalamus in vivo. PRL induced Egr-1 mRNA expression in 4B cells, an effect which was prevented by the MEK inhibitor, U0126. In vivo, intracerebroventricular PRL (1 microg) increased Egr-1 mRNA levels in the hypothalamic paraventricular (PVN) and supraoptic nuclei (SON) of female rats. The increase in mRNA paralleled elevated Egr-1 protein expression in the PVN and SON. Double staining immunohistochemistry revealed Egr-1 localization in oxytocin neurons of the PVN and SON, but not in vasopressin neurons in these regions. In the dorsomedial PVN, a population of non-oxytocin or vasopressin cells localized in a region corresponding to corticotropin-releasing hormone neurons also showed marked Egr-1 immunoreactivity. The data suggest that PRL modulates plasticity in oxytocinergic neurons, through MAP kinase-dependent induction of Egr-1.
Collapse
Affiliation(s)
- Annegret Blume
- Department of Behavioural and Molecular Neuroendocrinology, Institute of Zoology, University of Regensburg, Regensburg, Germany
| | | | | | | | | | | |
Collapse
|
28
|
Blume A, Torner L, Liu Y, Subburaju S, Aguilera G, Neumann ID. Prolactin activates mitogen-activated protein kinase signaling and corticotropin releasing hormone transcription in rat hypothalamic neurons. Endocrinology 2009; 150:1841-9. [PMID: 19022892 PMCID: PMC2659278 DOI: 10.1210/en.2008-1023] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Prolactin (PRL) modulates maternal behavior and mediates hypothalamic pituitary adrenal axis inhibition during lactation via PRL receptors in the brain. To identify mechanisms mediating these effects, we examined the effects of PRL on signaling and CRH transcription in hypothalamic neurons in vivo and in vitro. Western blot of hypothalamic proteins from rats receiving intracerebroventricular PRL injection revealed increases in phosphorylation of the MAPK and ERK. Double-staining immunohistochemistry demonstrated phosphorylated ERK localization in parvocellular CRH neurons as well as magnocellular vasopressin and oxytocin neurons of the hypothalamic paraventricular (PVN) and supraoptic nuclei. PRL also induced ERK phosphorylation in vitro in the hypothalamic cell line, 4B, which expresses PRL receptors, and in primary hypothalamic neuronal cultures. Using reporter gene assays in 4B cells, or quantitative RT-PCR for primary transcript in hypothalamic cell cultures, PRL potentiated forskolin-stimulated CRH transcription through activation of the ERK/MAPK pathway. The effect of PRL in hypothalamic cell cultures was unaffected by tetrodotoxin, suggesting a direct effect on CRH neurons. The data show that PRL activates the ERK/MAPK pathway and facilitates CRH transcription in CRH neurons, suggesting that the inhibitory effect of PRL on hypothalamo-pituitary-adrenal axis activity reported in vivo is indirect and probably mediated through modulation of afferent pathways to the PVN. In addition, the prominent stimulatory action of PRL on the ERK/MAPK pathway in the hypothalamic PVN and supraoptic nucleus is likely to mediate neuroplasticity of the neuroendocrine system during lactation.
Collapse
Affiliation(s)
- Annegret Blume
- Department of Behavioural and Molecular Neuroendocrinology, Institute of Zoology, University of Regensburg, 93053 Regensburg, Germany
| | | | | | | | | | | |
Collapse
|
29
|
Abstract
The neuroendocrine control of prolactin secretion is unlike that of any other pituitary hormone. It is predominantly inhibited by the hypothalamus and, in the absence of a regulatory feedback hormone, it acts directly in the brain to suppress its own secretion. In addition to this short-loop feedback action in the brain, prolactin has been reported to influence a wide range of other brain functions. There have been few attempts to rationalise why a single hormone might exert such a range of distinct and seemingly unrelated neuroendocrine functions. In this review, we highlight some of the original studies that first characterised the unusual features of prolactin neuroendocrinology, and then attempt to identify areas of new progress and/or controversy. Finally, we discuss a hypothesis that provides a unifying explanation for the pleiotrophic actions of prolactin in the brain.
Collapse
Affiliation(s)
- D R Grattan
- Centre for Neuroendocrinology and Department of Anatomy and Structural Biology, University of Otago, Dunedin, New Zealand.
| | | |
Collapse
|
30
|
Grattan DR, Steyn FJ, Kokay IC, Anderson GM, Bunn SJ. Pregnancy-induced adaptation in the neuroendocrine control of prolactin secretion. J Neuroendocrinol 2008; 20:497-507. [PMID: 18266946 DOI: 10.1111/j.1365-2826.2008.01661.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
During pregnancy, neuroendocrine control of prolactin secretion is markedly altered to allow a state of hyperprolactinaemia to develop. Prolactin secretion is normally tightly regulated by a short-loop negative-feedback mechanism, whereby prolactin stimulates activity of tuberoinfundibular dopamine (TIDA) neurones to increase dopamine secretion into the pituitary portal blood. Dopamine inhibits prolactin secretion, thus reducing prolactin concentrations in the circulation back to the normal low level. Activation of this feedback secretion by placental lactogen during pregnancy maintains relatively low levels of prolactin secretion during early and mid-pregnancy. Despite the continued presence of placental lactogen, however, dopamine secretion from TIDA neurones is reduced during late pregnancy. Moreover, the neurones become completely unresponsive to endogenous or exogenous prolactin at this time, allowing a large nocturnal surge of prolactin to occur from the maternal pituitary gland during the night before parturition. In this review, we describe the changing patterns of prolactin secretion during pregnancy in the rat, and discuss the neuroendocrine mechanisms controlling these changes. The loss of response to prolactin is an important maternal adaptation to pregnancy, allowing the prolonged period of hyperprolactinaemia required for mammary gland development and function and for maternal behaviour immediately after parturition, and possibly also contributing to a range of other adaptive responses in the mother.
Collapse
Affiliation(s)
- David R Grattan
- Centre for Neuroendocrinology and Department of Anatomy and Structural Biology, University of Otago, Dunedin, New Zealand.
| | | | | | | | | |
Collapse
|
31
|
Roselli CE, Bocklandt S, Stadelman HL, Wadsworth T, Vilain E, Stormshak F. Prolactin expression in the sheep brain. Neuroendocrinology 2008; 87:206-15. [PMID: 18223310 DOI: 10.1159/000114643] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Accepted: 12/10/2007] [Indexed: 11/19/2022]
Abstract
Accumulating evidence in rodents suggests that a prolactin locally synthesized and released within the brain can act together with that taken up from the circulation to modulate neuroendocrine responses. The present study was designed to identify the regional patterns of prolactin expression in the adult and developing sheep brain. Specifically, we tested the hypothesis that prolactin is expressed in regions of the adult and fetal sheep brain that are critical in the development of neuroendocrine homeostatic and behavioral functions. The expression of prolactin protein in sheep brain was demonstrated by Western blot analysis and brain prolactin mRNA was detected and sequenced using RT-PCR. In situ hybridization histochemistry revealed that prolactin mRNA was expressed in the medial preoptic area, periventricular preoptic nucleus, bed nucleus of the stria terminalis, and in the paraventricular nucleus of the hypothalamus, particularly the ventral region. The neuroanatomical distribution of prolactin mRNA was best visualized in the fetus and prolactin-immunoreactive neurons could also be identified in late gestation fetuses. Brain prolactin mRNA was expressed as early as day 60 of gestation and increased as the fetus aged and peaked at day 135 (term = 147 days). Prolactin mRNA expression did not exhibit a sex difference in the preoptic area, but in the amygdala prolactin mRNA was significantly higher in females than in males at day 100 of gestation. We conclude that prolactin expressed in adult and fetal sheep brain could be involved in neurodevelopment and/or modulation of the neuroendocrine stress axis, although it is too early to rule out other possibilities given the diverse actions that have been attributed to prolactin.
Collapse
Affiliation(s)
- Charles E Roselli
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, Oreg. 97201-3098, USA.
| | | | | | | | | | | |
Collapse
|
32
|
Nogami H, Hoshino R, Ogasawara K, Miyamoto S, Hisano S. Region-specific expression and hormonal regulation of the first exon variants of rat prolactin receptor mRNA in rat brain and anterior pituitary gland. J Neuroendocrinol 2007; 19:583-93. [PMID: 17620100 DOI: 10.1111/j.1365-2826.2007.01565.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Recent studies have revealed the occurrence of five first exon variants of the rat prolactin receptor mRNA, suggesting that multiple promoters direct prolactin receptor transcription in response to different regulatory factors. In the present study, regional expression of these first exon variants, as well as two prolactin receptor subtypes generated by alternative splicing, was examined in the brains and anterior pituitary glands of female rats. Expression of the long-form was detected in the choroid plexus, hypothalamus, hippocampus, cerebral cortex and anterior pituitary gland, whereas the short form was detected only in the choroid plexus. E1-3 mRNA, a first exon variant, was detected in the choroid plexus, hypothalamus, and anterior pituitary gland, whereas E1-4 was detected only in the choroid plexus. Other variants were not detectable by the polymerase chain reaction protocol employed in this study. Ovariectomy increased the short form in the choroid plexus and the E1-3 expression in the choroid plexus and pituitary gland, but changes in the long-form and E1-4 expression were minimal. Replacement of oestrogens and prolactin suggest that oestrogens down-regulate E1-3 expression in the choroid plexus and pituitary gland, and that the negative effect of oestrogen is mediated by prolactin in the pituitary gland. The present results revealed the region-specific promoter usage in prolactin receptor mRNA transcription, as well as the involvement of oestrogens in the regulation of E1-3 mRNA expression in the brain and pituitary gland.
Collapse
Affiliation(s)
- H Nogami
- Department of Neuroendocrinology, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, Japan.
| | | | | | | | | |
Collapse
|
33
|
San Martín R, Hurtado W, Quezada C, Reyes AE, Vera MI, Krauskopf M. Gene structure and seasonal expression of carp fish prolactin short receptor isoforms. J Cell Biochem 2007; 100:970-80. [PMID: 17131379 DOI: 10.1002/jcb.21081] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The complex adaptive mechanisms that eurythermal fish have evolved in response to the seasonal changes of the environment include the transduction of the physical parameter variations into neuroendocrine signals. Studies in carp (Cyprinus carpio) have indicated that prolactin (PRL) and growth hormone (GH) expression is associated with acclimatization, suggesting that the pituitary gland is a relevant physiological node in this adaptive process. Also, the distinctive pattern of expression that carp prolactin receptor (PRLr) protein depicts upon seasonal acclimatization supports the hypothesis that PRL and its receptor clearly are involved in the new homeostatic stage that the eurythermal fish needs to survive during the cyclical changes of its habitat. Here, we characterize the first prolactin receptor gene in a teleost and show that its expression is not associated with alternative promoters, unlike in humans and rodents. Using the regulatory region to direct the transcription of green fluorescent protein (GFP) in zebrafish embryos, we mapped the appearance of this hormone receptor during fish development. This is the first report identifying a fish prolactin receptor gene expressing transcript isoforms encoding for short forms of the protein (45 kDa). These have been found in osmoregulatory tissues of the carp and are regulated in connection with the seasonal acclimatization of the fish.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Western
- Carps/genetics
- Carps/metabolism
- Cloning, Molecular
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Fish Proteins/genetics
- Fish Proteins/metabolism
- Gene Expression
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- Male
- Microscopy, Fluorescence
- Models, Genetic
- Molecular Sequence Data
- Promoter Regions, Genetic/genetics
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- Receptors, Prolactin/genetics
- Receptors, Prolactin/metabolism
- Seasons
- Sequence Analysis, DNA
- Zebrafish/embryology
- Zebrafish/genetics
- Zebrafish/metabolism
Collapse
Affiliation(s)
- Rody San Martín
- Department of Biological Sciences, Millennium Institute for Fundamental and Applied Biology, Universidad Andrés Bello, Santiago, Chile
| | | | | | | | | | | |
Collapse
|
34
|
Kokay IC, Bull PM, Davis RL, Ludwig M, Grattan DR. Expression of the long form of the prolactin receptor in magnocellular oxytocin neurons is associated with specific prolactin regulation of oxytocin neurons. Am J Physiol Regul Integr Comp Physiol 2006; 290:R1216-25. [PMID: 16410399 DOI: 10.1152/ajpregu.00730.2005] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Magnocellular neurons of the supraoptic (SON) and paraventricular nuclei (PVN) show considerable plasticity during pregnancy and lactation. Prolactin receptors (PRL-R) have been identified in both these nuclei. The aim of this study was to investigate the cell type(s) expressing mRNA for the long form of prolactin receptor (PRL-RL) and to determine whether patterns of expression change during pregnancy and lactation. In addition, we examined effects of prolactin on excitability of oxytocin and vasopressin neurons. Sections from brains of nonpregnant, pregnant, and lactating rats were hybridized with an 35S-labeled probe to label PRL-RL mRNA together with digoxigenin-labeled probes to detect either oxytocin or vasopressin mRNA. In the SON, PRL-RL mRNA was predominantly colocalized with oxytocin mRNA, with over 80% of oxytocin neurons positive for PRL-RL mRNA. Very few (<10%) vasopressin neurons expressed PRL-RL mRNA. In the PVN, PRL-RL mRNA was also predominantly found in oxytocin neurons, and the proportion of PRL-RL-positive oxytocin neurons increased significantly during pregnancy and lactation. As in the SON, relatively few vasopressin cells contained PRL-RL mRNA. For in vivo electrophysiology, nonpregnant rats were anesthetized, and then extracellular single neuron activity was recorded in identified oxytocin and vasopressin neurons. After a period of baseline recording, the effect of prolactin (1 μg icv) on firing rate was examined. Prolactin treatment of nonpregnant rats induced a significant decrease in firing rates of oxytocin neurons. There was no effect of prolactin on the activity of vasopressin neurons. Together, these data provide strong evidence that prolactin directly and specifically regulates activity of oxytocin neurons.
Collapse
Affiliation(s)
- I C Kokay
- Centre for Neuroendocrinology and Dept. of Anatomy and Structural Biology, Univ. of Otago, P.O. Box 913, Dunedin, New Zealand
| | | | | | | | | |
Collapse
|
35
|
Kokay IC, Grattan DR. Expression of mRNA for prolactin receptor (long form) in dopamine and pro-opiomelanocortin neurones in the arcuate nucleus of non-pregnant and lactating rats. J Neuroendocrinol 2005; 17:827-35. [PMID: 16280030 DOI: 10.1111/j.1365-2826.2005.01374.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Under most conditions, prolactin secretion from the pituitary gland is subject to negative-feedback regulation. Prolactin stimulates dopamine release from tuberoinfundibular (TIDA) neurones in the arcuate nucleus of the hypothalamus, which in turn suppresses the production of prolactin. However, during late pregnancy and continuing into lactation, this feedback mechanism becomes less responsive to prolactin and, as a result, a hyperprolactinaemic state develops. We investigated whether long-form prolactin receptor (PRL-R(L)) mRNA is present on TIDA neurones in nonpregnant and lactating rats. In addition, we examined whether PRL-R(L) mRNA is colocalized on hypothalamic pro-opiomelanocortin (POMC) neurones. Dual-label in situ hybridizations using an (35)S-labelled cRNA probe specific for long-form PRL-R, together with a digoxigenin-labelled RNA probe that encoded either tyrosine hydroxylase (TH) or POMC mRNA, were performed on brain sections. In both nonpregnant and lactating rats, the majority of TH mRNA-positive cells (> 90%) were found to express long-form PRL-R mRNA. In sections from nonpregnant rats, few non-TH positive cells expressed PRL-R(L) mRNA. By contrast, during lactation, the proportion of PRL-R(L) mRNA-positive cells that were not TH mRNA-positive increased to approximately 70%. Only a small number of neurones in this subpopulation of PRL-R(L) mRNA-positive neurones were found to be positive for POMC mRNA. These data show that the loss of responsiveness to prolactin occurring during lactation is not due to down regulation of long-form PRL-R gene expression on TIDA neurones. Moreover, the persistent expression of PRL-R(L) in arcuate neuroendocrine circuits suggests that PRL-R-mediated signalling continues to be important in these neurones during lactation.
Collapse
Affiliation(s)
- I C Kokay
- Centre for Neuroendocrinology and Department of Anatomy and Structural Biology, University of Otago, Dunedin, New Zealand.
| | | |
Collapse
|
36
|
Bridges RS, Hays LE. Steroid-induced alterations in mRNA expression of the long form of the prolactin receptor in the medial preoptic area of female rats: Effects of exposure to a pregnancy-like regimen of progesterone and estradiol. ACTA ACUST UNITED AC 2005; 140:10-6. [PMID: 16107292 DOI: 10.1016/j.molbrainres.2005.06.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2004] [Revised: 06/13/2005] [Accepted: 06/15/2005] [Indexed: 11/22/2022]
Abstract
It is firmly established that the onset of maternal behavior in the female rat is stimulated by a combination of hormones that include prolactin (PRL), estradiol (E2), and progesterone (P(4)). Specifically, nulliparous rats display short latencies to respond to foster young when primed with Silastic capsules filled with P4 and E2 and then administered PRL centrally to the medial preoptic area (MPOA), an area integrally involved in the expression of maternal behavior in this species. PRL or P4 treatments alone are ineffective in stimulating the expression of maternal care. Since the actions of PRL in the MPOA appear to be mediated by PRL receptors, it was of interest to determine whether and how treatment with P4 and E2 together or separately might alter mRNA expression of the long form of the PRL receptor (PRL-R(L)) in the MPOA. Using in situ hybridization histochemistry (ISHH), mRNA expression of the PRL-R(L) was measured in the MPOA of ovariectomized, nulliparous rats treated with various combinations of P4 and E2. Treatment of animals with P4 alone for 10 days or with P4 followed by E2 for 1 or 4 days resulted in reductions in PRL receptor mRNA expression in the MPOA when compared with the expression in animals treated with E2 alone or blank capsules. The actions of P4 on mRNA expression of the PRL-R(L) were more pronounced in the dorsal MPOA. Circulating PRL levels collected at the time of sacrifice were elevated in all groups treated with E2, but no association between PRL levels and receptor mRNA expression within the MPOA was evident. These findings indicate that the dorsal MPOA may be one site of progesterone's action in facilitating prolactin-mediated maternal behavior.
Collapse
Affiliation(s)
- Robert S Bridges
- Department of Biomedical Sciences, Tufts University, Cummings School of Veterinary Medicine, 200 Westboro Road, North Grafton, MA 01536, USA.
| | | |
Collapse
|
37
|
Johanson CE, Duncan JA, Stopa EG, Baird A. Enhanced Prospects for Drug Delivery and Brain Targeting by the Choroid Plexus–CSF Route. Pharm Res 2005; 22:1011-37. [PMID: 16028003 DOI: 10.1007/s11095-005-6039-0] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Accepted: 04/12/2005] [Indexed: 02/07/2023]
Abstract
The choroid plexus (CP), i.e., the blood-cerebrospinal fluid barrier (BCSFB) interface, is an epithelial boundary exploitable for drug delivery to brain. Agents transported from blood to lateral ventricles are convected by CSF volume transmission (bulk flow) to many periventricular targets. These include the caudate, hippocampus, specialized circumventricular organs, hypothalamus, and the downstream pia-glia and arachnoid membranes. The CSF circulatory system normally provides micronutrients, neurotrophins, hormones, neuropeptides, and growth factors extensively to neuronal networks. Therefore, drugs directed to CSF can modulate a variety of endocrine, immunologic, and behavioral phenomema; and can help to restore brain interstitial and cellular homeostasis disrupted by disease and trauma. This review integrates information from animal models that demonstrates marked physiologic effects of substances introduced into the ventricular system. It also recapitulates how pharmacologic agents administered into the CSF system prevent disease or enhance the brain's ability to recover from chemical and physical insults. In regard to drug distribution in the CNS, the BCSFB interaction with the blood-brain barrier is discussed. With a view toward translational CSF pharmacotherapy, there are several promising innovations in progress: bone marrow cell infusions, CP encapsulation and transplants, neural stem cell augmentation, phage display of peptide ligands for CP epithelium, CSF gene transfer, regulation of leukocyte and cytokine trafficking at the BCSFB, and the purification of neurotoxic CSF in degenerative states. The progressively increasing pharmacological significance of the CP-CSF nexus is analyzed in light of treating AIDS, multiple sclerosis, stroke, hydrocephalus, and Alzheimer's disease.
Collapse
Affiliation(s)
- Conrad E Johanson
- Department of Clinical Neurosciences, Rhode Island Hospital, Brown Medical School, Providence, Rhode Island 02912, USA.
| | | | | | | |
Collapse
|
38
|
Ma E, Lau J, Grattan DR, Lovejoy DA, Wynne-Edwards KE. Male and female prolactin receptor mRNA expression in the brain of a biparental and a uniparental hamster, phodopus, before and after the birth of a litter. J Neuroendocrinol 2005; 17:81-90. [PMID: 15796758 DOI: 10.1111/j.1365-2826.2005.01278.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Prolactin receptor (PRL-R) mRNA transcript level was quantified in the choroid plexus (ChP) of a naturally biparental hamster, Phodopus campbelli, and its otherwise similar, yet nonpaternal, sibling species, Phodopus sungorus. Pair-housed males and females on the day before the birth of their first litter (G17), the day after birth (L1), lactation day 5 (L5), and unpaired animals that were sexually naïve, were tested. PRL-R mRNA transcript level relative to total RNA, was evaluated by reverse transcriptase-polymerase chain reaction using primers common to the long- and short-form of the PRL-R in Phodopus. In the ChP, a region implicated in prolactin transport into the central nervous system, females had the expected increase in PRL-R mRNA transcript from dioestrus to L5, consistent with known actions of prolactin. As predicted, males and females of the biparental species were similar, although PRL-R mRNA in naive males was higher than in dioestrus females. Males of the two species also differed as predicted. PRL-R mRNA transcript levels were higher in the biparental males. In addition, P. campbelli males had low PRL-R mRNA at G17 compared to L5. By contrast, non-paternal P. sungorus males had elevated PRL-R mRNA transcript levels on G17 relative to unpaired males. We conclude that PRL-R mRNA in the ChP is differentially regulated before and after birth in a paternal and a nonpaternal male.
Collapse
Affiliation(s)
- E Ma
- Department of Biology, Queen's University, Kingston, Canada
| | | | | | | | | |
Collapse
|
39
|
Torner L, Maloumby R, Nava G, Aranda J, Clapp C, Neumann ID. In vivo release and gene upregulation of brain prolactin in response to physiological stimuli. Eur J Neurosci 2004; 19:1601-8. [PMID: 15066156 DOI: 10.1111/j.1460-9568.2004.03264.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although prolactin (PRL) actions and expression in the brain have been shown, dynamic changes in its intracerebral release and gene expression have still not been demonstrated. Using push-pull perfusion, the in vivo release of PRL was monitored within the paraventricular nucleus (PVN) and medial preoptic area (MPOA) of virgin female, lactating and male rats in response to various stimuli. Perfusion with a depolarizing medium (56 mm K(+)) increased local release of PRL within both the PVN (P < 0.05) and MPOA (P < 0.05) of urethane-anaesthetized rats, indicating release from excitable neuronal structures. The PRL in perfusates was verified by radioimmunoassay, Nb2 cell bioassays and western blot. Systemic osmotic stimulation (3 m NaCl i.p., 8 mL/kg b.w.) raised PRL concentration in plasma (P < 0.01) but not within the PVN, suggesting independent release from the pituitary and in distinct brain regions. Immobilization for 30 min increased PRL release within the PVN (P < 0.05) and the MPOA (P < 0.01) of virgin female and male (P < 0.05 each) rats and increased hypothalamic PRL mRNA expression (P = 0.008) after 30 and 90 min as revealed by real-time polymerase chain reaction. This indicates a stress-induced activation of both PRL release from and synthesis in hypothalamic neurons. Additionally, PRL was significantly released within, but not outside, the PVN (P < 0.01) and the MPOA (P < 0.05) of lactating rats during suckling and this was accompanied by a significant increase of PRL mRNA (P < 0.05) in the hypothalamus 60 min after suckling. This is the first demonstration of stimulus-induced, locally restricted release and gene upregulation of PRL within the brain, emphasizing the involvement of this 'novel' neuropeptide in various brain functions.
Collapse
Affiliation(s)
- Luz Torner
- University of Regensburg, Institute of Zoology, Universitätsstrasse 31, 93053 Regensburg, Germany.
| | | | | | | | | | | |
Collapse
|