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Altitude, temperature, circadian rhythms and exercise
Published in Adam P. Sharples, James P. Morton, Henning Wackerhage, Molecular Exercise Physiology, 2022
Henning Wackerhage, Kenneth A. Dyar, Martin Schönfelder
Temperature is sensed by TRP ion channels in the skin, viscera, spinal cord and by the brain. But where does this information go to be processed and to trigger responses to a “too hot” or “too cold” sensation? First, researchers noted that animals rapidly increased their body temperature when they damaged the base of the brain, suggesting that this houses the thermoregulatory centre (43, 44). Today we know that thermoregulatory centre is located in the hypothalamus, specifically in the preoptic area and in the anterior part.
Endocrine Functions of Brain Dopamine
Published in Nira Ben-Jonathan, Dopamine, 2020
The hypothalamus is the primary site that integrates incoming sensory and peripheral signals and coordinates the behavioral response. Other regions, including the VTA, periaqeductal gray and prefrontal cortex, also contribute to reproductive behaviors [81]. Lesions in the medial preoptic area (MPOA) of the hypothalamus prevent key elements of sexual behavior in both males and females, and disrupt maternal behavior in females. The MPOA contains neurons that are responsive to sex steroids and is sexually dimorphic, i.e., it is larger and has more neurons in males than in female rodents. Additional studies have showed that individual neurons in the MPOA fire during sexual stimulation.
Neuroendocrine Morphology
Published in Paul V. Malven, Mammalian Neuroendocrinology, 2019
Other components of the limbic system include the septum, olfactory gray, and parts of the cerebral cortex (i.e., cingulate gyrus and hippocampal gyrus). The epithalamus and its associated pineal gland should probably be considered functionally part of the limbic system although they were not included in the original designation. Finally, the hypothalamus is the part of the limbic system most intimately involved with neuroendocrinology. Not only does it contain perikarya of neurons which participate in neuroendocrine regulation and integration, but it contains many tracts which connect with other parts of the limbic system. The preoptic area is included herein as a functional part of the hypothalamus although morphological classifications often list the preoptic area as a separate entity. The major fiber pathways connecting the hypothalamus with limbic and non-limbic structures are depicted in Figure 2-3 in a schematic and highly simplified diagram.
Theoretical construct into blocks of actigraphic-derived sleep parameters
Published in Chronobiology International, 2023
Letizia Galasso, Giovanna Calogiuri, Lucia Castelli, Antonino Mulè, Fabio Esposito, Andrea Caumo, Angela Montaruli, Eliana Roveda
The timing of nocturnal sleep is regulated by different neurochemical systems connected with each other, including the preoptic area and the suprachiasmatic nucleus, which receive afferences directly from retinal fibers (Buijs et al. 2003; Dijk and Lockley 2002; Sack 2009; Sothern et al. 2009). The suprachiasmatic nucleus is deemed as the main internal regulator of circadian rhythms and its degeneration can causes loss of entrainment with the daylight periodicity, the most important external synchronizer of the different rhythms (Buijs et al. 2003; Delaunay et al. 2000; Lee et al. 2000; Whitmore 2001), and desynchronization of endogenous behavioral and hormonal rhythms including the sleep-wake cycle. Hence, the endogenous rhythm of the sleep-wake cycle is, in normal conditions, synchronized with the alternation of day-night cycle, as well as other factors such as timing of meals and social routines. Such synchronization is important in order to maintain healthy sleep-wake patterns, as in fact its disruptions can lead to emergence of different sleep problems (Sack et al. 2007a, 2007b).
Impact of COVID 19 on erectile function
Published in The Aging Male, 2022
D. H. Adeyemi, A. F. Odetayo, M. A. Hamed, R. E. Akhigbe
The process that culminates in penile erection entails a mix of several physiological conditions that border on the input from both central and peripheral nervous systems. Besides, there are a series of the interplay between several biological mediators, vasoactive agents, neurotransmitters, and endocrine agents to achieve the optimal erection necessary for sexual intercourse [48]. The central processing unit in response to tactile, visual, and imaginative stimuli enhances penile erection. In other words, the central and peripheral control systems remain the two major established pathways that regulate or control penile erection. Stimulations of the peripheral tissues involved in erection elicit the response that is controlled by spinal and somatic activities. In addition, evidence from animal studies has suggested that the central control of sexual arousal or erection is predominantly localized in the limbic system structures. The medial preoptic area, paraventricular nucleus, medial amygdala, nucleus acumens, ventral tegmental area, and hippocampus are primary structures in the regulation of male sexual response [49]. Subsequently, a spinal network consisting of primary afferent signals emanating from the genitals, spinal interneurons, sympathetic, parasympathetic, and somatic nuclei are responsible for integrating signals from the periphery thus eliciting reflexive erections [50].
Preoptic bombesin-like receptor-3 neurons heat it up
Published in Temperature, 2022
Ramón A. Piñol, Marc L. Reitman
A defining characteristic of endotherms, including mammals, is a warm, highly regulated, and stable core body temperature (Tb). Identifying the network of neurons controlling Tb is essential for understanding this fundamental physiology. The preoptic area (POA) is a brain region that receives afferent and local Tb sensory information and harbors efferent neurons of autonomic and behavioral thermoregulatory pathways [1]. These pathways contribute to thermoregulatory behavior, shivering and non-shivering thermogenesis, cutaneous vasomotion and cardiovascular responses. Researchers have identified POA neuronal populations in mice that reduce Tb when activated, regulating heat defense, torpor, and thermoregulation during sleep. A dozen such populations are marked by the expression of genes encoding enzymes, neuropeptides, and/or receptors and are predominantly glutamatergic. Future studies will need to better characterize these heterogenous neuronal populations, uncovering overlaps and defining subpopulations with more precise roles. A POA population that increases Tb when activated has been proposed and likely uses glutamatergic projections to the dorsomedial hypothalamus (DMH) [2]. We have now identified POA neurons expressing bombesin-like receptor-3 (POABRS3) as the first defined, specific population whose activation increases Tb [3]. This is driven by non-shivering thermogenesis through brown adipose tissue (BAT) activation, with concomitant increases in heart rate and blood pressure.