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Hormones and Behavior Jul 2017Since Arnold Adolph Berthold established in 1849 the critical role of the testes in the activation of male sexual behavior, intensive research has identified many... (Review)
Review
Since Arnold Adolph Berthold established in 1849 the critical role of the testes in the activation of male sexual behavior, intensive research has identified many sophisticated neurochemical and molecular mechanisms mediating this action. Studies in Japanese quail demonstrated the critical role of testosterone action and of testosterone aromatization in the sexually dimorphic medial preoptic nucleus in the activation of male copulatory behavior. The development of an immunohistochemical visualization of brain aromatase in quail then allowed further refinement in the localization of the sites of neuroestrogens production. Testosterone aromatization is required for the activation of both appetitive and consummatory aspects of male sexual behavior. Brain aromatase activity is modulated by steroid-induced changes in the transcription of the corresponding gene but also more rapidly by phosphorylation processes. Sexual interactions with a female also rapidly regulate brain aromatase activity in an anatomically specific manner presumably via the release and action of endogenous glutamate. These rapid changes in estrogen production modulate sexual behavior and in particular its motivational component with latencies ranging between 15 and 30min. Brain estrogens seem to act in a manner akin to a neurotransmitter or at least a neuromodulator. More recently, assays of brain estradiol concentrations in micropunched samples or in dialysis samples obtained from behaviorally active males suggested that aromatase activity measured ex vivo might not be an accurate proxy to the rapid changes in local neuroestrogens production and concentrations. Studies of brain testosterone metabolism are thus not over and will keep scientists busy for a little longer. Elsevier SBN Keynote Address, Montreal.
Topics: Animals; Aromatase; Brain; Coturnix; Estrogen Receptor beta; Estrogens; Female; Humans; Male; Masculinity; Models, Animal; Preoptic Area; Sexual Behavior; Social Behavior; Testosterone
PubMed: 28576650
DOI: 10.1016/j.yhbeh.2017.05.017 -
Frontiers in Neuroendocrinology Oct 2021Male sexual behavior is subject to learning, resulting in increased efficiency of experienced males compared to naive ones. The improvement in behavioral parameters is... (Review)
Review
Male sexual behavior is subject to learning, resulting in increased efficiency of experienced males compared to naive ones. The improvement in behavioral parameters is underpinned by cellular and molecular changes in the neural circuit controlling sexual behavior, particularly in the hypothalamic medial preoptic area. This review provides an update on the mechanisms related to the sexual experience in male rodents, emphasizing the differences between rats and mice.
Topics: Animals; Hypothalamus; Male; Mice; Preoptic Area; Rats; Sexual Behavior, Animal
PubMed: 34687674
DOI: 10.1016/j.yfrne.2021.100949 -
Cell Metabolism Jul 2021The preoptic area (POA) is a key brain region for regulation of body temperature (Tb), dictating thermogenic, cardiovascular, and behavioral responses that control Tb....
The preoptic area (POA) is a key brain region for regulation of body temperature (Tb), dictating thermogenic, cardiovascular, and behavioral responses that control Tb. Previously characterized POA neuronal populations all reduced Tb when activated. Using mice, we now identify POA neurons expressing bombesin-like receptor 3 (POA) as a population whose activation increased Tb; inversely, acute inhibition of these neurons reduced Tb. POA neurons that project to either the paraventricular nucleus of the hypothalamus or the dorsomedial hypothalamus increased Tb, heart rate, and blood pressure via the sympathetic nervous system. Long-term inactivation of POA neurons caused increased Tb variability, overshooting both increases and decreases in Tb set point, with RNA expression profiles suggesting multiple types of POA neurons. Thus, POA neuronal populations regulate Tb and heart rate, contribute to cold defense, and fine-tune feedback control of Tb. These findings advance understanding of homeothermy, a defining feature of mammalian biology.
Topics: Animals; Body Temperature; Body Temperature Regulation; Heart Rate; Male; Mice; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Transgenic; Neurons; Preoptic Area; Receptors, Bombesin; Signal Transduction; Sympathetic Nervous System; Thermogenesis
PubMed: 34038711
DOI: 10.1016/j.cmet.2021.05.001 -
Neuroscience Letters May 2016The decrease in serotonergic neurotransmission during aging can increase the risk of neuropsychiatric diseases such as depression in elderly population and decline the...
The decrease in serotonergic neurotransmission during aging can increase the risk of neuropsychiatric diseases such as depression in elderly population and decline the reproductive system. Therefore, it is important to understand the age-associated molecular mechanisms of brain aging. In this study, the effect of aging and chronic escitalopram (antidepressant) treatment to admit mice was investigated by comparing transcriptomes in the preoptic area (POA) which is a key nucleus for reproduction. In the mid-aged brain, the immune system-related genes were increased and hormone response-related genes were decreased. In the escitalopram treated brains, transcription-, granule cell proliferation- and vasoconstriction-related genes were increased and olfactory receptors were decreased. Since homeostasis and neuroprotection-related genes were altered in both of mid-age and escitalopram treatment, these genes could be important for serotonin related physiologies in the POA.
Topics: Age Factors; Animals; Citalopram; Male; Mice, Inbred C57BL; Preoptic Area; Serotonin; Selective Serotonin Reuptake Inhibitors; Transcriptome
PubMed: 27113202
DOI: 10.1016/j.neulet.2016.04.052 -
Nature Communications Oct 2018The preoptic area (POA) is necessary for sleep, but the fundamental POA circuits have remained elusive. Previous studies showed that galanin (GAL)- and GABA-producing...
The preoptic area (POA) is necessary for sleep, but the fundamental POA circuits have remained elusive. Previous studies showed that galanin (GAL)- and GABA-producing neurons in the ventrolateral preoptic nucleus (VLPO) express cFos after periods of increased sleep and innervate key wake-promoting regions. Although lesions in this region can produce insomnia, high frequency photostimulation of the POA neurons was shown to paradoxically cause waking, not sleep. Here we report that photostimulation of VLPO neurons in mice promotes sleep with low frequency stimulation (1-4 Hz), but causes conduction block and waking at frequencies above 8 Hz. Further, optogenetic inhibition reduces sleep. Chemogenetic activation of VLPO neurons confirms the increase in sleep, and also reduces body temperature. In addition, chemogenetic activation of VLPO neurons induces short-latency sleep in an animal model of insomnia. Collectively, these findings establish a causal role of VLPO neurons in both sleep induction and heat loss.
Topics: Animals; Body Temperature Regulation; Electroencephalography; Electromyography; Galanin; Gene Expression Profiling; Male; Mice, Transgenic; Neurons; Preoptic Area; Sleep; Sleep Initiation and Maintenance Disorders
PubMed: 30297727
DOI: 10.1038/s41467-018-06590-7 -
Nature Neuroscience Apr 2021
Topics: Anxiety; Anxiety Disorders; Humans; Parents; Preoptic Area
PubMed: 33674751
DOI: 10.1038/s41593-021-00812-w -
ELife Mar 2021Adjuvant tamoxifen therapy improves survival in breast cancer patients. Unfortunately, long-term treatment comes with side effects that impact health and quality of...
Adjuvant tamoxifen therapy improves survival in breast cancer patients. Unfortunately, long-term treatment comes with side effects that impact health and quality of life, including hot flashes, changes in bone density, and fatigue. Partly due to a lack of proven animal models, the tissues and cells that mediate these negative side effects are unclear. Here, we show that mice undergoing tamoxifen treatment experience changes in temperature, bone, and movement. Single-cell RNA sequencing reveals that tamoxifen treatment induces widespread gene expression changes in the hypothalamus and preoptic area (hypothalamus-POA). These expression changes are dependent on estrogen receptor alpha (ERα), as conditional knockout of ERα in the hypothalamus-POA ablates or reverses tamoxifen-induced gene expression. Accordingly, ERα-deficient mice do not exhibit tamoxifen-induced changes in temperature, bone, or movement. These findings provide mechanistic insight into the effects of tamoxifen on the hypothalamus-POA and indicate that ERα mediates several physiological effects of tamoxifen treatment in mice.
Topics: Animals; Antineoplastic Agents, Hormonal; Body Temperature; Bone Density; Estrogen Receptor alpha; Female; Gene Expression Regulation; Hypothalamus; Mice; Movement; Preoptic Area; Tamoxifen
PubMed: 33647234
DOI: 10.7554/eLife.63333 -
Physiology & Behavior Sep 2020Aggressive competition for resources among juveniles is documented in many species, but the neural mechanisms regulating this behavior in young animals are poorly...
Aggressive competition for resources among juveniles is documented in many species, but the neural mechanisms regulating this behavior in young animals are poorly understood. In poison frogs, increased parental care is associated with decreased water volume of tadpole pools, resource limitation, and aggression. Indeed, the tadpoles of many poison frog species will attack, kill, and cannibalize other tadpoles. We examined the neural basis of conspecific aggression in Dyeing poison frog (Dendrobates tinctorius) tadpoles by comparing individuals that won aggressive encounters, lost aggressive encounters, or did not engage in a fight. We first compared patterns of generalized neural activity using immunohistochemical detection of phosphorylated ribosomes (pS6) as a proxy for neural activation associated with behavior. We found increased neural activity in the medial pallium and preoptic area of loser tadpoles, suggesting the amphibian homologs of the mammalian hippocampus and preoptic area may facilitate loser-associated behaviors. Nonapeptides (arginine vasotocin and mesotocin) and dopamine have been linked to aggression in other vertebrates and are located in the preoptic area. We next examined neural activity specifically in nonapeptide- and tyrosine-hydroxylase-positive cells using double-label immunohistochemistry. We found increased neural activity specifically in the preoptic area nonapeptide neurons of winners, whereas we found no differences in activity of dopaminergic cells among behavioral groups. Our findings suggest the neural correlates of aggression in poison frog tadpoles are similar to neural mechanisms mediating aggression in adults and juveniles of other vertebrate taxa.
Topics: Aggression; Animals; Anura; Larva; Poisons; Preoptic Area; Vasotocin
PubMed: 32446779
DOI: 10.1016/j.physbeh.2020.112973 -
Handbook of Clinical Neurology 2021The intermediate nucleus of Brockhaus (INH), also known as the interstitial nucleus of the anterior hypothalamus-1 of Allen and Gorski (INAH-1), the sexually dimorphic... (Review)
Review
The intermediate nucleus of Brockhaus (INH), also known as the interstitial nucleus of the anterior hypothalamus-1 of Allen and Gorski (INAH-1), the sexually dimorphic nucleus of Swaab and colleagues (SDN), and the ventrolateral preoptic nucleus of Saper and colleagues (VLPO), is a cluster of largely galanin-expressing neurons in the lateral preoptic area, at the level of the crossing of the anterior commissure and dorsal to the supraoptic nucleus. The number of Nissl-stained neurons in the INH has been reported to be larger in men than women and to decrease with aging, although these findings have been controversial, in part because of differences in patient populations and methods used to assess the nucleus. However, recent studies have confirmed that the number of galanin-immunoreactive INH neurons is larger in men than women and decreases with age and have reported further loss with Alzheimer disease. The galanin-immunoreactive VLPO neurons have been thought to drive sleep behavior in many species, and their numbers in older humans correlate with the amount of consolidated sleep they experience. Sleep differences between men and women, during aging, and with Alzheimer disease may also depend upon the integrity of this nucleus.
Topics: Aged; Alzheimer Disease; Female; Galanin; Humans; Male; Preoptic Area; Sex Characteristics; Sexual Behavior; Sleep
PubMed: 34225983
DOI: 10.1016/B978-0-12-819975-6.00030-3 -
Neuroscience Nov 2021Hypocretins (HCRT), also known as orexins, includes two neuroexcitatory peptides, HCRT-1 and HCRT-2 (orexin A y B, respectively), synthesized by neurons located in the...
Hypocretins (HCRT), also known as orexins, includes two neuroexcitatory peptides, HCRT-1 and HCRT-2 (orexin A y B, respectively), synthesized by neurons located in the postero-lateral hypothalamus, whose projections and receptors are widely distributed throughout the brain, including the medial preoptic area (mPOA). HCRT have been associated with a wide range of physiological functions including sleep-wake cycle, maternal behavior and body temperature, all regulated by the mPOA. Previously, we showed that HCRT in the mPOA facilitates certain active maternal behaviors, while the blockade of HCRT-R1 increases the time spent in nursing. As mother rats mainly sleep while they nurse, we hypothesize that HCRT in the mPOA of lactating rats reduce sleep and nursing, while intra-mPOA administration of a dual orexin receptor antagonist (DORA) would cause the opposite effect. Therefore, the aim of this study was to determine the role of HCRT within the mPOA, in the regulation and integration of the sleep-wake cycle, maternal behavior and body temperature of lactating rats. For that purpose, we assessed the sleep-wake states, maternal behavior and body temperature of lactating rats following microinjections of HCRT-1 (100 and 200 µM) and DORA (5 mM) into the mPOA. As expected, our data show that HCRT-1 in mPOA promote wakefulness and a slightly increase in body temperature, whereas DORA increases both NREM and REM sleep together with an increment of nursing and milk ejection. Taken together, our results strongly suggest that the endogenous reduction of HCRT within the mPOA contribute to the promotion of sleep, milk ejection and nursing behavior in lactating rats.
Topics: Animals; Body Temperature; Female; Humans; Lactation; Maternal Behavior; Orexins; Preoptic Area; Rats; Sleep
PubMed: 34500018
DOI: 10.1016/j.neuroscience.2021.08.034