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Endocrinology Sep 1976The present study was designed to determine the effects of bilateral lesions restricted to the medial preoptic area on reproductive function in rats. Adult female rats...
The present study was designed to determine the effects of bilateral lesions restricted to the medial preoptic area on reproductive function in rats. Adult female rats were placed in a stereotaxic instrument, and bilateral lesions were made in the medial preoptic area of the diencephalon using an anodic current and platinum or stainless steel electrodes. Both types of lesions produced identical effects. Most animals with lesions restricted to the medial preoptic area showed repeated periods of pseudopregnancy for the duration of their lives. Ova were detected in the oviducts on the day of estrus between pseudopregnancies, and deciduomata could be produced by uterine traumatization during pseudopregnancy. Daily administration of lergotrile mesylate, a dopamine agonist, for about two weeks, to the pseudopregnant rats with lesions resulted in the appearance of normal 4 or 5-day estrous cycles. These results suggest that the medial preoptic area may not be necessary for ovulation in the rat, and that the normal function of the preoptic area in the control of reproductive cyclicity may be mediated via dopaminergic neurons. In agreement with earlier studies, we found that lesions that extended into the anterior hypothalamus resulted in constant estrus.
Topics: Acetonitriles; Animals; Ergolines; Estrus; Female; Hypothalamus; Pregnancy; Preoptic Area; Prolactin; Pseudopregnancy; Rats; Reproduction
PubMed: 986293
DOI: 10.1210/endo-99-3-728 -
Behavioural Brain Research Feb 2011A large body of evidence has established the role of the medial preoptic area (mPOA) in regulation of slow wave sleep (SWS). Although the mPOA neurons contain excitatory...
A large body of evidence has established the role of the medial preoptic area (mPOA) in regulation of slow wave sleep (SWS). Although the mPOA neurons contain excitatory neurotransmitter glutamate, its role in sleep-wakefulness is not known. In the present study microinjection of monosodium glutamate (40, 80 and 120 ng) into the mPOA augmented SWS. Earlier reports have shown enhancement of paradoxical sleep by glutamate in other brain areas.
Topics: Animals; Dose-Response Relationship, Drug; Male; Microinjections; Preoptic Area; Rats; Rats, Wistar; Sleep; Sodium Glutamate; Wakefulness
PubMed: 21070818
DOI: 10.1016/j.bbr.2010.11.007 -
Behavioural Brain Research Jun 2019Parental care by fathers enhances offspring survival and development in numerous species. In the biparental California mouse, Peromyscus californicus, behavioral...
Parental care by fathers enhances offspring survival and development in numerous species. In the biparental California mouse, Peromyscus californicus, behavioral plasticity is seen during the transition into fatherhood: adult virgin males often exhibit aggressive or indifferent responses to pups, whereas fathers engage in extensive paternal care. In this species and other biparental mammals, the onset of paternal behavior is associated with increased neural responsiveness to pups in specific brain regions, including the medial preoptic area of the hypothalamus (MPOA), a region strongly implicated in both maternal and paternal behavior. To assess possible changes in neural circuit properties underlying this increased excitability, we evaluated synaptic, intrinsic, and morphological properties of MPOA neurons in adult male California mice that were either virgins or first-time fathers. We used standard whole-cell recordings in a novel in vitro slice preparation. Excitatory and inhibitory post-synaptic currents from MPOA neurons were recorded in response to local electrical stimulation, and input/output curves were constructed for each. Responses to trains of stimuli were also examined. We quantified intrinsic excitability by measuring voltage changes in response to square-pulse injections of both depolarizing and hyperpolarizing current. Biocytin was injected into neurons during recording, and their morphology was analyzed. Most parameters did not differ significantly between virgins and fathers. However, we document a decrease in synaptic inhibition in fathers. These findings suggest that the onset of paternal behavior in California mouse fathers may be associated with limited electrophysiological plasticity within the MPOA.
Topics: Animals; Behavior, Animal; Brain; Fathers; Male; Mice; Neuronal Plasticity; Neurons; Paternal Behavior; Peromyscus; Preoptic Area
PubMed: 30802534
DOI: 10.1016/j.bbr.2019.02.029 -
Brain Research Apr 1992The effects of 17 beta-estradiol (E2) on calcitonin gene-related peptide (CGRP)- and methionine-enkephalin (Met-Enk)-immunoreactive (IR) nerve fibers in the... (Comparative Study)
Comparative Study
Semi-quantitative analysis of the effects of estrogen on CGRP- and methionine-enkephalin-immunoreactivity in the periventricular preoptic nucleus and the medial preoptic area of female rats.
The effects of 17 beta-estradiol (E2) on calcitonin gene-related peptide (CGRP)- and methionine-enkephalin (Met-Enk)-immunoreactive (IR) nerve fibers in the periventricular preoptic nucleus (Pe) and the medial preoptic area, including the medial preoptic nucleus (MPN), of the female rat were studied semi-quantitatively by using a computer-based image analysis system. The area occupied by CGRP- and Met-Enk-IR fibers was significantly increased in the Pe and the MPN after 28-day exposure to E2. Computer-based analysis of CGRP- and Met-Enk-IR fibers in an area of 50-microns intervals from the wall of the third ventricle showed a low flat histogram pattern in ovariectomized rats, but E2 treatment caused a diphasic pattern, corresponding to the Pe and the MPN, respectively. Since the Pe and the MPN contain a high population of estrogen receptors, it is suggested that E2 may have an influence on the neuronal configuration of afferent fibers to these areas.
Topics: Animals; Calcitonin Gene-Related Peptide; Cerebral Ventricles; Enkephalin, Methionine; Estradiol; Female; Immunohistochemistry; Nerve Fibers; Ovariectomy; Preoptic Area; Rats; Rats, Inbred Strains
PubMed: 1511281
DOI: 10.1016/0006-8993(92)90259-c -
Molecular Neurobiology Jan 2018The neurovascular unit (NVU) can be conceptualized as a functional entity consisting of neurons, astrocytes, pericytes, and endothelial and smooth muscle cells that...
The neurovascular unit (NVU) can be conceptualized as a functional entity consisting of neurons, astrocytes, pericytes, and endothelial and smooth muscle cells that operate in concert to affect blood flow to a very circumscribed area. Although we are currently in a "golden era" of bioengineering, there are, as yet, no living NVUs-on-a-chip modules available and the development of a neural chip that would mimic NVUs is a seemingly lofty goal. The sexually dimorphic nucleus of the preoptic area (SDN-POA) is a tiny brain structure (between 0.001~0.007 mm in rats) with an assessable biological function (i.e., male sexual behavior). The present effort was undertaken to determine whether there are identifiable NVUs in the SDN-POA by assessing its vasculature relative to its known neural components. First, a thorough and systematic review of thousands of histologic and immunofluorescent images from 201 weanling and adult rats was undertaken to define the characteristics of the vessels supplying the SDN-POA: its primary supply artery/arteriole and capillaries are physically inseparable from their neural elements. A subsequent immunofluorescent study targeting α-smooth muscle actin confirmed the identity of an artery/arteriole supplying the SDN-POA. In reality, the predominant components of the SDN-POA are calbindin D28k-positive neurons that are comingled with tyrosine hydroxylase-positive projections. Finally, a schematic of an SDN-POA NVU is proposed as a working model of the basic building block of the CNS. Such modules could serve the study of neurovascular mechanisms and potentially inform the development of next generation bioengineered neural transplants, i.e., the construct of an NVU neural chip.
Topics: Animals; Female; Male; Nerve Net; Neurons; Preoptic Area; Rats; Rats, Sprague-Dawley; Sex Characteristics
PubMed: 28840477
DOI: 10.1007/s12035-017-0729-6 -
Brain Research Jan 1989Lesions of the preoptic area of rabbits caused hyperthermia, although they did not alter sleep-coupled changes in brain temperature, and reduced slow-wave sleep, rapid...
Lesions of the preoptic area of rabbits caused hyperthermia, although they did not alter sleep-coupled changes in brain temperature, and reduced slow-wave sleep, rapid eye movement sleep, and amplitudes of electroencephalographic slow waves during slow wave sleep. The direction and magnitude of the muramyl dipeptide-induced responses were similar before and after the lesions, although the baseline values upon which the changes were superimposed had shifted.
Topics: Acetylmuramyl-Alanyl-Isoglutamine; Animals; Electroencephalography; Fever; Male; Preoptic Area; Rabbits; Sleep; Sleep Stages; Time Factors
PubMed: 2702477
DOI: 10.1016/0006-8993(89)91267-5 -
Brain Structure & Function Jul 2017The present study aims to examine the origin of oligodendrocyte progenitor cells (OPCs) in the mouse optic nerve (ON) by labeling OPCs in the fetal forebrain. The...
The present study aims to examine the origin of oligodendrocyte progenitor cells (OPCs) in the mouse optic nerve (ON) by labeling OPCs in the fetal forebrain. The labeling of OPCs in the ON was performed by injection of a retrovirus vector carrying the lacZ gene into the lateral ventricle, or by inducible Cre/loxP of Olig2-positive cells. The retrovirus labeling revealed that ventricular zone-derived cells of the fetal forebrain relocated to the ON and differentiated into oligodendrocytes. In addition, lineage tracing of Olig2-positive cells and whole-mount staining of PDGFRα-positive cells demonstrated that OPCs appeared by E12.5 in the preoptic area, and spread caudally to enter the ON. Our results also suggest that OPCs generated during the early stage are depleted from the ON after maturation.
Topics: Animals; Cell Differentiation; Cell Lineage; Eye; Mice; Oligodendrocyte Precursor Cells; Oligodendrocyte Transcription Factor 2; Oligodendroglia; Optic Nerve; Preoptic Area
PubMed: 28293728
DOI: 10.1007/s00429-017-1394-2 -
Acta Physiologica (Oxford, England) May 2015Located in the midline anterior wall of the third cerebral ventricle (i.e. the lamina terminalis), the median preoptic nucleus (MnPO) receives a unique set of afferent... (Review)
Review
Located in the midline anterior wall of the third cerebral ventricle (i.e. the lamina terminalis), the median preoptic nucleus (MnPO) receives a unique set of afferent neural inputs from fore-, mid- and hindbrain. These afferent connections enable it to receive neural signals related to several important aspects of homeostasis. Included in these afferent projections are (i) neural inputs from two adjacent circumventricular organs, the subfornical organ and organum vasculosum laminae terminalis, that respond to hypertonicity, circulating angiotensin II or other humoural factors, (ii) signals from cutaneous warm and cold receptors that are relayed to MnPO, respectively, via different subnuclei in the lateral parabrachial nucleus and (iii) input from the medulla associated with baroreceptor and vagal afferents. These afferent signals reach appropriate neurones within the MnPO that enable relevant neural outputs, both excitatory and inhibitory, to be activated or inhibited. The efferent neural pathways that proceed from the MnPO terminate on (i) neuroendocrine cells in the hypothalamic supraoptic and paraventricular nuclei to regulate vasopressin release, while polysynaptic pathways from MnPO to cortical sites may drive thirst and water intake, (ii) thermoregulatory pathways to the dorsomedial hypothalamic nucleus and medullary raphé to regulate shivering, brown adipose tissue and skin vasoconstriction, (iii) parvocellular neurones in the hypothalamic paraventricular nucleus that drive autonomic pathways influencing cardiovascular function. As well, (iv) other efferent pathways from the MnPO to sites in the ventrolateral pre-optic nucleus, perifornical region of the lateral hypothalamic area and midbrain influence sleep mechanisms.
Topics: Animals; Body Fluids; Body Temperature Regulation; Cardiovascular Physiological Phenomena; Homeostasis; Humans; Preoptic Area; Sleep; Sodium
PubMed: 25753944
DOI: 10.1111/apha.12487 -
Brain Research Oct 2003Chemosensory cues from receptive females do not elicit similar reactions before and after puberty in male hamsters. While pheromones facilitate a complex display of...
Chemosensory cues from receptive females do not elicit similar reactions before and after puberty in male hamsters. While pheromones facilitate a complex display of reproductive behavior in adults, prepubertal males do not engage in these same behaviors. Dopamine (DA) released from the medial preoptic area (MPOA) in response to a receptive female or her odors is an important component of the neural events underlying adult male rat sexual behavior. The current experiment investigated whether increased dopaminergic activity occurs in the adult male hamster MPOA in response to female pheromones, and if so, whether this response is absent in prepubertal males, which do not mate. Sexually nai;ve prepubertal and adult male hamsters were exposed to cotton swabs with or without pheromone from an estrous female for 0, 5, 15, or 25 min, after which brains were collected and frozen on dry ice. The MPOA was micropunched from frozen coronal sections (500 microm), and concentrations of DA and its primary metabolite DOPAC were determined by high-performance liquid chromatography-electrochemical detection. DOPAC was used as an index of dopaminergic activity. DOPAC levels significantly increased in adults after 15 min exposure to pheromone. In contrast, MPOA DOPAC concentrations did not increase in prepubertal males exposed to pheromone. These data demonstrate that the neural processing of sexually relevant chemosensory stimuli matures during puberty. The absence of a DA response to female pheromones prior to puberty may contribute to the inability of prepubertal males to display reproductive behavior.
Topics: 3,4-Dihydroxyphenylacetic Acid; Animals; Chromatography, High Pressure Liquid; Cricetinae; Dopamine; Female; Male; Mesocricetus; Pheromones; Preoptic Area; Sexual Behavior, Animal; Sexual Maturation; Testosterone
PubMed: 14519535
DOI: 10.1016/s0006-8993(03)03358-4 -
Cell and Tissue Research Jan 2019The paraventricular nucleus (PVN) of the hypothalamus harbors diverse neurosecretory cells with critical physiological roles for the homeostasis. Decades of research in... (Review)
Review
The paraventricular nucleus (PVN) of the hypothalamus harbors diverse neurosecretory cells with critical physiological roles for the homeostasis. Decades of research in rodents have provided a large amount of information on the anatomy, development, and function of this important hypothalamic nucleus. However, since the hypothalamus lies deep within the brain in mammals and is difficult to access, many questions regarding development and plasticity of this nucleus still remain. In particular, how different environmental conditions, including stress exposure, shape the development of this important nucleus has been difficult to address in animals that develop in utero. To address these open questions, the transparent larval zebrafish with its rapid external development and excellent genetic toolbox offers exciting opportunities. In this review, we summarize recent information on the anatomy and development of the neurosecretory preoptic area (NPO), which represents a similar structure to the mammalian PVN in zebrafish. We will then review recent studies on the development of different cell types in the neurosecretory hypothalamus both in mouse and in fish. Lastly, we discuss stress-induced plasticity of the PVN mainly discussing the data obtained in rodents, but pointing out tools and approaches available in zebrafish for future studies. This review serves as a primer for the currently available information relevant for studying the development and plasticity of this important brain region using zebrafish.
Topics: Animals; Hypothalamus; Neuronal Plasticity; Neurosecretory Systems; Preoptic Area; Stress, Physiological; Zebrafish
PubMed: 30109407
DOI: 10.1007/s00441-018-2900-4