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Advances in Physiology Education Sep 2015Thermoregulation is the maintenance of a relatively constant core body temperature. Humans normally maintain a body temperature at 37°C, and maintenance of this... (Review)
Review
Thermoregulation is the maintenance of a relatively constant core body temperature. Humans normally maintain a body temperature at 37°C, and maintenance of this relatively high temperature is critical to human survival. This concept is so important that control of thermoregulation is often the principal example cited when teaching physiological homeostasis. A basic understanding of the processes underpinning temperature regulation is necessary for all undergraduate students studying biology and biology-related disciplines, and a thorough understanding is necessary for those students in clinical training. Our aim in this review is to broadly present the thermoregulatory process taking into account current advances in this area. First, we summarize the basic concepts of thermoregulation and subsequently assess the physiological responses to heat and cold stress, including vasodilation and vasoconstriction, sweating, nonshivering thermogenesis, piloerection, shivering, and altered behavior. Current research is presented concerning the body's detection of thermal challenge, peripheral and central thermoregulatory control mechanisms, including brown adipose tissue in adult humans and temperature transduction by the relatively recently discovered transient receptor potential channels. Finally, we present an updated understanding of the neuroanatomic circuitry supporting thermoregulation.
Topics: Adaptation, Physiological; Adult; Body Temperature; Body Temperature Regulation; Female; Fever; Humans; Hypothermia; Male; Sensitivity and Specificity; Shivering; Skin Temperature; Sweating; Thermoreceptors; Thermosensing
PubMed: 26330029
DOI: 10.1152/advan.00126.2014 -
International Journal of Molecular... Oct 2022Sleep is a fundamental, evolutionarily conserved, plastic behavior that is regulated by circadian and homeostatic mechanisms as well as genetic factors and environmental... (Review)
Review
Sleep is a fundamental, evolutionarily conserved, plastic behavior that is regulated by circadian and homeostatic mechanisms as well as genetic factors and environmental factors, such as light, humidity, and temperature. Among environmental cues, temperature plays an important role in the regulation of sleep. This review presents an overview of thermoreception in animals and the neural circuits that link this process to sleep. Understanding the influence of temperature on sleep can provide insight into basic physiologic processes that are required for survival and guide strategies to manage sleep disorders.
Topics: Animals; Circadian Rhythm; Temperature; Sleep; Homeostasis; Plastics
PubMed: 36293048
DOI: 10.3390/ijms232012191 -
Science (New York, N.Y.) Nov 2018The hypothalamus controls essential social behaviors and homeostatic functions. However, the cellular architecture of hypothalamic nuclei-including the molecular...
The hypothalamus controls essential social behaviors and homeostatic functions. However, the cellular architecture of hypothalamic nuclei-including the molecular identity, spatial organization, and function of distinct cell types-is poorly understood. Here, we developed an imaging-based in situ cell-type identification and mapping method and combined it with single-cell RNA-sequencing to create a molecularly annotated and spatially resolved cell atlas of the mouse hypothalamic preoptic region. We profiled ~1 million cells, identified ~70 neuronal populations characterized by distinct neuromodulatory signatures and spatial organizations, and defined specific neuronal populations activated during social behaviors in male and female mice, providing a high-resolution framework for mechanistic investigation of behavior circuits. The approach described opens a new avenue for the construction of cell atlases in diverse tissues and organisms.
Topics: Animals; Atlases as Topic; Female; Galanin; Gene Expression Profiling; In Situ Hybridization, Fluorescence; Male; Mice; Neurons; Pituitary Adenylate Cyclase-Activating Polypeptide; Preoptic Area; Sequence Analysis, RNA; Single-Cell Analysis; Social Behavior
PubMed: 30385464
DOI: 10.1126/science.aau5324 -
Science (New York, N.Y.) Oct 2023During pregnancy, physiological adaptations prepare the female body for the challenges of motherhood. Becoming a parent also requires behavioral adaptations. Such...
During pregnancy, physiological adaptations prepare the female body for the challenges of motherhood. Becoming a parent also requires behavioral adaptations. Such adaptations can occur as early as during pregnancy, but how pregnancy hormones remodel parenting circuits to instruct preparatory behavioral changes remains unknown. We found that action of estradiol and progesterone on galanin (Gal)-expressing neurons in the mouse medial preoptic area (MPOA) is critical for pregnancy-induced parental behavior. Whereas estradiol silences MPOA neurons and paradoxically increases their excitability, progesterone permanently rewires this circuit node by promoting dendritic spine formation and recruitment of excitatory synaptic inputs. This MPOA-specific neural remodeling sparsens population activity in vivo and results in persistently stronger, more selective responses to pup stimuli. Pregnancy hormones thus remodel parenting circuits in anticipation of future behavioral need.
Topics: Animals; Female; Mice; Pregnancy; Estradiol; Maternal Behavior; Parenting; Preoptic Area; Progesterone; Models, Animal; Neurons
PubMed: 37797007
DOI: 10.1126/science.adi0576 -
Neuron Apr 2018The regulation of body temperature is one of the most critical functions of the nervous system. Here we review our current understanding of thermoregulation in mammals.... (Review)
Review
The regulation of body temperature is one of the most critical functions of the nervous system. Here we review our current understanding of thermoregulation in mammals. We outline the molecules and cells that measure body temperature in the periphery, the neural pathways that communicate this information to the brain, and the central circuits that coordinate the homeostatic response. We also discuss some of the key unresolved issues in this field, including the following: the role of temperature sensing in the brain, the molecular identity of the warm sensor, the central representation of the labeled line for cold, and the neural substrates of thermoregulatory behavior. We suggest that approaches for molecularly defined circuit analysis will provide new insight into these topics in the near future.
Topics: Animals; Body Temperature; Body Temperature Regulation; Brain; Homeostasis; Humans; Neural Pathways; Thermosensing
PubMed: 29621489
DOI: 10.1016/j.neuron.2018.02.022 -
Science (New York, N.Y.) Sep 2017Water deprivation produces a drive to seek and consume water. How neural activity creates this motivation remains poorly understood. We used activity-dependent genetic...
Water deprivation produces a drive to seek and consume water. How neural activity creates this motivation remains poorly understood. We used activity-dependent genetic labeling to characterize neurons activated by water deprivation in the hypothalamic median preoptic nucleus (MnPO). Single-cell transcriptional profiling revealed that dehydration-activated MnPO neurons consist of a single excitatory cell type. After optogenetic activation of these neurons, mice drank water and performed an operant lever-pressing task for water reward with rates that scaled with stimulation frequency. This stimulation was aversive, and instrumentally pausing stimulation could reinforce lever-pressing. Activity of these neurons gradually decreased over the course of an operant session. Thus, the activity of dehydration-activated MnPO neurons establishes a scalable, persistent, and aversive internal state that dynamically controls thirst-motivated behavior.
Topics: Animals; Cell Line; Dehydration; Drinking Behavior; Gene Expression Profiling; Mice; Motivation; Neurons; Optogenetics; Preoptic Area; Single-Cell Analysis; TNF Receptor-Associated Factor 2; Thirst
PubMed: 28912243
DOI: 10.1126/science.aan6747 -
Nature Neuroscience Apr 2021Anxiety is a negative emotional state that is overly displayed in anxiety disorders and depression. Although anxiety is known to be controlled by distributed brain...
Anxiety is a negative emotional state that is overly displayed in anxiety disorders and depression. Although anxiety is known to be controlled by distributed brain networks, key components for its initiation, maintenance and coordination with behavioral state remain poorly understood. Here, we report that anxiogenic stressors elicit acute and prolonged responses in glutamatergic neurons of the mouse medial preoptic area (mPOA). These neurons encode extremely negative valence and mediate the induction and expression of anxiety-like behaviors. Conversely, mPOA GABA-containing neurons encode positive valence and produce anxiolytic effects. Such opposing roles are mediated by competing local interactions and long-range projections of neurons to the periaqueductal gray. The two neuronal populations antagonistically regulate anxiety-like and parental behaviors: anxiety is reduced, while parenting is enhanced and vice versa. Thus, by evaluating negative and positive valences through distinct but interacting circuits, the mPOA coordinates emotional state and social behavior.
Topics: Animals; Anxiety; Behavior, Animal; Female; GABAergic Neurons; Glutamine; Male; Mice; Mice, Inbred C57BL; Neurons; Preoptic Area; Social Behavior; Stress, Psychological
PubMed: 33526942
DOI: 10.1038/s41593-020-00784-3 -
Nature Jun 2022During infection, animals exhibit adaptive changes in physiology and behaviour aimed at increasing survival. Although many causes of infection exist, they trigger...
During infection, animals exhibit adaptive changes in physiology and behaviour aimed at increasing survival. Although many causes of infection exist, they trigger similar stereotyped symptoms such as fever, warmth-seeking, loss of appetite and fatigue. Yet exactly how the nervous system alters body temperature and triggers sickness behaviours to coordinate responses to infection remains unknown. Here we identify a previously uncharacterized population of neurons in the ventral medial preoptic area (VMPO) of the hypothalamus that are activated after sickness induced by lipopolysaccharide (LPS) or polyinosinic:polycytidylic acid. These neurons are crucial for generating a fever response and other sickness symptoms such as warmth-seeking and loss of appetite. Single-nucleus RNA-sequencing and multiplexed error-robust fluorescence in situ hybridization uncovered the identity and distribution of LPS-activated VMPO (VMPO) neurons and non-neuronal cells. Gene expression and electrophysiological measurements implicate a paracrine mechanism in which the release of immune signals by non-neuronal cells during infection activates nearby VMPO neurons. Finally, we show that VMPO neurons exert a broad influence on the activity of brain areas associated with behavioural and homeostatic functions and are synaptically and functionally connected to circuit nodes controlling body temperature and appetite. Together, these results uncover VMPO neurons as a control hub that integrates immune signals to orchestrate multiple sickness symptoms in response to infection.
Topics: Animals; Appetite; Appetite Depressants; Fever; In Situ Hybridization, Fluorescence; Infections; Lipopolysaccharides; Neurons; Paracrine Communication; Poly I-C; Preoptic Area
PubMed: 35676482
DOI: 10.1038/s41586-022-04793-z -
Nature Sep 2021Transient neuromodulation can have long-lasting effects on neural circuits and motivational states. Here we examine the dopaminergic mechanisms that underlie mating...
Transient neuromodulation can have long-lasting effects on neural circuits and motivational states. Here we examine the dopaminergic mechanisms that underlie mating drive and its persistence in male mice. Brief investigation of females primes a male's interest to mate for tens of minutes, whereas a single successful mating triggers satiety that gradually recovers over days. We found that both processes are controlled by specialized anteroventral and preoptic periventricular (AVPV/PVpo) dopamine neurons in the hypothalamus. During the investigation of females, dopamine is transiently released in the medial preoptic area (MPOA)-an area that is critical for mating behaviours. Optogenetic stimulation of AVPV/PVpo dopamine axons in the MPOA recapitulates the priming effect of exposure to a female. Using optical and molecular methods for tracking and manipulating intracellular signalling, we show that this priming effect emerges from the accumulation of mating-related dopamine signals in the MPOA through the accrual of cyclic adenosine monophosphate levels and protein kinase A activity. Dopamine transients in the MPOA are abolished after a successful mating, which is likely to ensure abstinence. Consistent with this idea, the inhibition of AVPV/PVpo dopamine neurons selectively demotivates mating, whereas stimulating these neurons restores the motivation to mate after sexual satiety. We therefore conclude that the accumulation or suppression of signals from specialized dopamine neurons regulates mating behaviours across minutes and days.
Topics: Animals; Copulation; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Dopamine; Dopaminergic Neurons; Drive; Female; Hypothalamus; Male; Mice; Optogenetics; Preoptic Area; Satiety Response; Sexual Behavior, Animal; Signal Transduction; Time Factors
PubMed: 34433964
DOI: 10.1038/s41586-021-03845-0