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Current Biology : CB Sep 2021The locus coeruleus (LC), which is located in the brain stem, plays an important role in promoting arousal. However, the neural circuitry underlying this function...
The locus coeruleus (LC), which is located in the brain stem, plays an important role in promoting arousal. However, the neural circuitry underlying this function remains unclear. Using cortical electroencephalography combined with optrode recording, we found that LC noradrenergic (LC) neurons exhibit high activity during wakefulness, while suppressing the activity of these neurons causes a reduction in wakefulness. Viral tracing showed that LC neurons directly project to the ventrolateral preoptic area (VLPO) and that optogenetic activation of the noradrenergic (NAergic) LC-VLPO (NAergic) neural circuit promotes arousal. Optrode recordings in the VLPO revealed two functionally distinct neuronal populations that were stimulated in response to the optogenetic activation of LC neurons. Consistently, we identified two types of VLPO neurons that exhibited different responses to NAergic projections from the LC mediated by discrete adrenergic receptors. Together, our results demonstrate that the NAergic neural circuit is a critical pathway for controlling wakefulness and that a synergistic effect is produced by inhibition of sleep-active neurons in the VLPO through α receptors and activation of wake-active neurons in the VLPO through α and β receptors.
Topics: Arousal; Locus Coeruleus; Preoptic Area; Sleep; Wakefulness
PubMed: 34270948
DOI: 10.1016/j.cub.2021.06.031 -
Journal of Neurophysiology Jan 2014The preoptic hypothalamus is implicated in sleep regulation. Neurons in the median preoptic nucleus (MnPO) and the ventrolateral preoptic area (VLPO) have been...
The preoptic hypothalamus is implicated in sleep regulation. Neurons in the median preoptic nucleus (MnPO) and the ventrolateral preoptic area (VLPO) have been identified as potential sleep regulatory elements. However, the extent to which MnPO and VLPO neurons are activated in response to changing homeostatic sleep regulatory demands is unresolved. To address this question, we continuously recorded the extracellular activity of neurons in the rat MnPO, VLPO and dorsal lateral preoptic area (LPO) during baseline sleep and waking, during 2 h of sleep deprivation (SD) and during 2 h of recovery sleep (RS). Sleep-active neurons in the MnPO (n = 11) and VLPO (n = 13) were activated in response to SD, such that waking discharge rates increased by 95.8 ± 29.5% and 59.4 ± 17.3%, respectively, above waking baseline values. During RS, non-rapid eye movement (REM) sleep discharge rates of MnPO neurons initially increased to 65.6 ± 15.2% above baseline values, then declined to baseline levels in association with decreases in EEG delta power. Increase in non-REM sleep discharge rates in VLPO neurons during RS averaged 40.5 ± 7.6% above baseline. REM-active neurons (n = 16) in the LPO also exhibited increased waking discharge during SD and an increase in non-REM discharge during RS. Infusion of A2A adenosine receptor antagonist into the VLPO attenuated SD-induced increases in neuronal discharge. Populations of LPO wake/REM-active and state-indifferent neurons and dorsal LPO sleep-active neurons were unresponsive to SD. These findings support the hypothesis that sleep-active neurons in the MnPO and VLPO, and REM-active neurons in the LPO, are components of neuronal circuits that mediate homeostatic responses to sustained wakefulness.
Topics: Action Potentials; Animals; Male; Neurons; Preoptic Area; Rats; Rats, Sprague-Dawley; Sleep Deprivation; Sleep Stages
PubMed: 24174649
DOI: 10.1152/jn.00504.2013 -
Neuroscience Letters Jun 2014In laboratory animals, less is known about the neural circuits that mediate paternal behavior than those that influence maternal behavior. In mice, we recently reported...
In laboratory animals, less is known about the neural circuits that mediate paternal behavior than those that influence maternal behavior. In mice, we recently reported that when sires are separated with their mate dams from their pups, ultrasound and pheromonal signals from the dams can evoke and initiate maternal-like retrieval behavior in the sires upon reunion with the offspring; this is termed mate-dependent paternal care. We used electrolytic brain lesion (EBL) methods to identify the potential roles of the medial preoptic area (mPOA) and ventral pallidum (VP) regions in regulating paternal care, areas known to be critical for the expression of maternal behavior. Electrolytic lesions of the mPOA or VP disrupted mate-dependent paternal care; latencies to initiate pup retrieval, grooming and crouching were longer in the EBL-treated sires relative to the sham-operated mice. The number of grooming episodes and duration of crouching were also lower in sires with the EBL in both areas. These results indicate that the mPOA and VP regions are essential for mate-dependent paternal care in mice.
Topics: Animals; Basal Forebrain; Electricity; Female; Male; Mice, Inbred ICR; Paternal Behavior; Preoptic Area
PubMed: 24721669
DOI: 10.1016/j.neulet.2014.03.078 -
BMC Neuroscience Nov 2023The medial preoptic area (mPOA) regulates the probability and intensity of singing behavior in birds. Polzin and colleagues examined the molecular changes in the mPOA...
The medial preoptic area (mPOA) regulates the probability and intensity of singing behavior in birds. Polzin and colleagues examined the molecular changes in the mPOA that were associated with gregarious song in European starlings (Sturnus vulgaris). High-throughput transcriptome analyses identified glutamate and dopamine pathways were highly enriched with gregarious song.
Topics: Animals; Vocalization, Animal; Sexual Behavior, Animal; Social Behavior; Starlings; Dopamine; Preoptic Area
PubMed: 37919674
DOI: 10.1186/s12868-023-00833-0 -
ELife Aug 2020Recent studies in mice demonstrate that a subset of neurons in the medial preoptic area (MPOA) that express galanin play crucial roles in regulating parental behavior in...
Recent studies in mice demonstrate that a subset of neurons in the medial preoptic area (MPOA) that express galanin play crucial roles in regulating parental behavior in both sexes. However, little information is available on the function of galanin in social behaviors in other species. Here, we report that, in medaka, a subset of MPOA galanin neurons occurred nearly exclusively in males, resulting from testicular androgen stimulation. Galanin-deficient medaka showed a greatly reduced incidence of male-male aggressive chases. Furthermore, while treatment of female medaka with androgen induced male-typical aggressive acts, galanin deficiency in these females attenuated the effect of androgen on chases. Given their male-biased and androgen-dependent nature, the subset of MPOA galanin neurons most likely mediate androgen-dependent male-male chases. Histological studies further suggested that variability in the projection targets of the MPOA galanin neurons may account for the species-dependent functional differences in these evolutionarily conserved neural substrates.
Topics: Androgens; Animals; Animals, Genetically Modified; Cell Line; Female; Galanin; Gene Expression; HEK293 Cells; Humans; Male; Neurons; Oryzias; Preoptic Area; Receptors, Galanin; Reproduction; Sex Characteristics; Signal Transduction; Steroids
PubMed: 32783809
DOI: 10.7554/eLife.59470 -
Neuroscience Aug 2012Histamine acts centrally to increase energy expenditure and reduce body weight by mechanisms not fully understood. It has been suggested that in the obese state...
Histamine acts centrally to increase energy expenditure and reduce body weight by mechanisms not fully understood. It has been suggested that in the obese state hypothalamic histamine signaling is altered. Previous studies have also shown that histamine acting in the preoptic area controls thermoregulation. We aimed to study the influence of preoptic histamine on body temperature and energy homeostasis in control and obese mice. Activating histamine receptors in the preoptic area by increasing the concentration of endogenous histamine or by local injection of specific agonists induced an elevation of core body temperature and decreased respiratory exchange ratio (RER). In addition, the food intake was significantly decreased. The hyperthermic effect was associated with a rapid increase in mRNA expression of uncoupling proteins in thermogenic tissues, the most pronounced being that of uncoupling protein (UCP) 1 in brown adipose tissue and of UCP2 in white adipose tissue. In diet-induced obese mice histamine had much diminished hyperthermic effects as well as reduced effect on RER. Similarly, the ability of preoptic histamine signaling to increase the expression of uncoupling proteins was abolished. We also found that the expression of mRNA encoding the H1 receptor subtype in the preoptic area was significantly lower in obese animals. These results indicate that histamine signaling in the preoptic area modulates energy homeostasis by regulating body temperature, metabolic parameters and food intake and that the obese state is associated with a decrease in neurotransmitter's influence.
Topics: Adipose Tissue, Brown; Animals; Body Temperature Regulation; Dimaprit; Eating; Energy Metabolism; Histamine; Histamine Agonists; Homeostasis; Mice; Mice, Obese; Obesity; Preoptic Area; Receptors, Histamine
PubMed: 22579982
DOI: 10.1016/j.neuroscience.2012.04.068 -
Scientific Reports Jul 2018The infusion of hypertonic saline solution (HSS) is known to be beneficial to the treatment of hypovolemic hemorrhage (HH). The central mechanism of HSS-induced...
The infusion of hypertonic saline solution (HSS) is known to be beneficial to the treatment of hypovolemic hemorrhage (HH). The central mechanism of HSS-induced cardiovascular and autonomic recovery of animals subjected to HH remains unclear. Hence, the present study evaluated the involvement of median preoptic nucleus (MnPO) and medullary noradrenergic neurons (A1 and A2) in HSS-induced cardiovascular and sympathetic responses in hemorrhagic rats. The wistar rats were subjected to specific lesion of noradrenergic neurons through the nanoinjections of anti-DβH-saporin into caudal ventrolateral medulla (A1 neurons) and nucleus of the solitary tract (A2 neurons). After recovery, mean arterial pressure (MAP) and renal sympathetic nervous activity were recorded. The HH was performed through blood withdrawal until a MAP of 60 mmHg was attained. In sham rats, HSS infusion (3M NaCl) reestablished MAP without change in HH-induced sympathoinhibition. The muscimol (agonist of GABA receptor) was nanoinjected in MnPO during HH and MnPO inhibition abolished the recovery of MAP and HSS-induced sympathoinhibition. Simultaneous lesions of A1 and A2 abolished MAP restoration and sympathoinhibition after HSS infusion. These results suggest that the recovery of MAP and HSS-induced sympathoinhibition in hemorrhaged rats depend on intact neural projections from A1 and A2 to MnPO.
Topics: Adaptation, Physiological; Adrenergic Neurons; Animals; Arterial Pressure; Cardiovascular Physiological Phenomena; Hemorrhage; Preoptic Area; Rats, Wistar; Sympathetic Nervous System
PubMed: 30050041
DOI: 10.1038/s41598-018-29310-z -
Cell Reports Jul 2018Hot flushes are a sudden feeling of warmth commonly associated with the decline of gonadal hormones at menopause. Neurons in the arcuate nucleus of the hypothalamus that...
Hot flushes are a sudden feeling of warmth commonly associated with the decline of gonadal hormones at menopause. Neurons in the arcuate nucleus of the hypothalamus that express kisspeptin and neurokinin B (Kiss1 neurons) are candidates for mediating hot flushes because they are negatively regulated by sex hormones. We used a combination of genetic and viral technologies in mice to demonstrate that artificial activation of Kiss1 neurons evokes a heat-dissipation response resulting in vasodilation (flushing) and a corresponding reduction of core-body temperature in both females and males. This response is sensitized by ovariectomy. Brief activation of Kiss1 axon terminals in the preoptic area of the hypothalamus recapitulates this response, while pharmacological blockade of neurokinin B (NkB) receptors in the same brain region abolishes it. We conclude that transient activation of Kiss1 neurons following sex-hormone withdrawal contributes to the occurrence of hot flushes via NkB release in the rostral preoptic area.
Topics: Animals; Axons; Estrogens; Female; Hot Temperature; Kisspeptins; Male; Mice; Neural Pathways; Neurokinin-1 Receptor Antagonists; Optogenetics; Preoptic Area; Proto-Oncogene Proteins c-fos; Receptors, Tachykinin; Vasodilation
PubMed: 29996088
DOI: 10.1016/j.celrep.2018.06.037 -
Journal of Chemical Neuroanatomy Jan 2011The posterodorsal preoptic nucleus (PdPN), lateral part of the posterodorsal medial amygdala (MeApd) and medial part of the medial preoptic nucleus (MPNm) are activated...
Distribution of catecholaminergic and peptidergic cells in the gerbil medial amygdala, caudal preoptic area and caudal bed nuclei of the stria terminalis with a focus on areas activated at ejaculation.
The posterodorsal preoptic nucleus (PdPN), lateral part of the posterodorsal medial amygdala (MeApd) and medial part of the medial preoptic nucleus (MPNm) are activated at ejaculation in male gerbils as assessed by Fos expression. We sought to immunocytochemically visualize substance P (SP), cholecystokinin (CCK), oxytocin, vasopressin and tyrosine hydroxylase (TH), a catecholaminergic marker, in the mating-activated cells, but the need for colchicine precluded behavioral testing. Instead, we detailed distributions of cells containing these molecules in the medial amygdala, caudal preoptic area and caudal bed nuclei of the stria terminalis (BST) and quantified their densities in the PdPN, MPNm and lateral MeApd for comparison to densities previously assessed for mating-activated efferents from these sites. TH cells were as dense in the PdPN and lateral MeApd as activated efferents to the anteroventral periventricular nucleus. In the lateral MeApd, TH cells were grouped where cells activated at ejaculation are clustered and where CCK cells form a ball. Lateral MeApd CCK cells and PdPN SP cells were as dense as activated efferents to the principal BST. Oxytocinergic PdPN cells and SP cells in the MPNm were as dense as mating-activated efferents to the lateral MeApd. If some oxytocin cells in the PdPN project to the neurohypophysis, as in rats, they could be a source of the oxytocin secreted at ejaculation. Since gerbils are monogamous and biparental, it was also interesting that, unlike monogamous prairie voles, they had few TH cells in the MeApd or dorsal BST, resembling promiscuous rats, hamsters and meadow voles.
Topics: Amygdala; Animals; Arvicolinae; Cell Nucleus; Cholecystokinin; Ejaculation; Female; Gerbillinae; Hypothalamus; Immunohistochemistry; Male; Oxytocin; Preoptic Area; Septal Nuclei; Substance P; Tyrosine 3-Monooxygenase; Vasopressins
PubMed: 21087661
DOI: 10.1016/j.jchemneu.2010.10.005 -
Journal of Applied Physiology... Feb 2019The present study investigated whether intrinsic exercise capacity affects the changes in thermoregulation, metabolism and central dopamine (DA) induced by treadmill... (Comparative Study)
Comparative Study
The present study investigated whether intrinsic exercise capacity affects the changes in thermoregulation, metabolism and central dopamine (DA) induced by treadmill running. Male Wistar rats were subjected to three incremental exercises and ranked as low-performance (LP), standard-performance (SP), and high-performance (HP) rats. In the first experiment, abdominal (T) and tail (T) temperatures were registered in these rats during submaximal exercise (SE) at 60% of maximal speed. Immediately after SE, rats were decapitated and concentrations of DA and 3,4-dihydroxyphenylacetic acid (DOPAC) were determined in the preoptic area (POA). In the second experiment, oxygen consumption was measured and mechanical efficiency (ME) was calculated in these rats during an incremental exercise. HP rats ran for longer periods and were fatigued with higher T values, with no difference in T. Nevertheless, thermoregulatory efficiency was higher in HP rats, compared with other groups. DA and DOPAC concentrations in the POA were increased by SE, with higher levels in HP compared with LP and SP rats. V̇o also differed between groups, with HP rats displaying a lower consumption throughout the incremental exercise but a higher V̇o at fatigue. ME, in turn, was consistently higher in HP than in LP and SP rats. Thus, our results show that HP rats have greater T values at fatigue, which seem to be related to a higher dopaminergic activity in the POA. Moreover, HP rats exhibited a greater thermoregulatory efficiency during exercise, which can be attributed to a lower V̇o, but not to changes in tail heat loss mechanisms. NEW & NOTEWORTHY Our findings reveal that rats with higher intrinsic exercise capacities have greater thermoregulatory efficiencies and increased dopaminergic activity in the preoptic area, a key brain area in thermoregulatory control, while exercising. Moreover, higher intrinsic exercise capacities are associated with decreased oxygen consumption for a given exercise intensity, which indicates greater mechanical efficiencies. Collectively, these findings help to advance our knowledge of why some rats of a given strain can exercise for longer periods than others.
Topics: 3,4-Dihydroxyphenylacetic Acid; Animals; Body Temperature Regulation; Dopamine; Exercise Tolerance; Male; Muscle Contraction; Muscle, Skeletal; Oxygen Consumption; Preoptic Area; Rats, Wistar; Running; Time Factors
PubMed: 29927731
DOI: 10.1152/japplphysiol.00092.2018