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Chaves T, Török B, Fazekas CL, Correia P, Sipos E, Várkonyi D, Tóth ZE, Dóra F, Dobolyi Á, Zelena D. The Dopaminergic Cells in the Median Raphe Region Regulate Social Behavior in Male Mice. Int J Mol Sci 2024; 25:4315. [PMID: 38673899 PMCID: PMC11050709 DOI: 10.3390/ijms25084315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 04/08/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
According to previous studies, the median raphe region (MRR) is known to contribute significantly to social behavior. Besides serotonin, there have also been reports of a small population of dopaminergic neurons in this region. Dopamine is linked to reward and locomotion, but very little is known about its role in the MRR. To address that, we first confirmed the presence of dopaminergic cells in the MRR of mice (immunohistochemistry, RT-PCR), and then also in humans (RT-PCR) using healthy donor samples to prove translational relevance. Next, we used chemogenetic technology in mice containing the Cre enzyme under the promoter of the dopamine transporter. With the help of an adeno-associated virus, designer receptors exclusively activated by designer drugs (DREADDs) were expressed in the dopaminergic cells of the MRR to manipulate their activity. Four weeks later, we performed an extensive behavioral characterization 30 min after the injection of the artificial ligand (Clozapine-N-Oxide). Stimulation of the dopaminergic cells in the MRR decreased social interest without influencing aggression and with an increase in social discrimination. Additionally, inhibition of the same cells increased the friendly social behavior during social interaction test. No behavioral changes were detected in anxiety, memory or locomotion. All in all, dopaminergic cells were present in both the mouse and human samples from the MRR, and the manipulation of the dopaminergic neurons in the MRR elicited a specific social response.
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Affiliation(s)
- Tiago Chaves
- Institute of Physiology, Medical School, Centre for Neuroscience, Szentágothai Research Centre, University of Pécs, H7624 Pécs, Hungary; (T.C.); (B.T.); (C.L.F.); (P.C.); (D.V.)
- Laboratory of Behavioral and Stress Studies, Institute of Experimental Medicine, H1083 Budapest, Hungary;
- János Szentágothai School of Neurosciences, Semmelweis University, H1085 Budapest, Hungary
| | - Bibiána Török
- Institute of Physiology, Medical School, Centre for Neuroscience, Szentágothai Research Centre, University of Pécs, H7624 Pécs, Hungary; (T.C.); (B.T.); (C.L.F.); (P.C.); (D.V.)
- Laboratory of Behavioral and Stress Studies, Institute of Experimental Medicine, H1083 Budapest, Hungary;
- János Szentágothai School of Neurosciences, Semmelweis University, H1085 Budapest, Hungary
| | - Csilla Lea Fazekas
- Institute of Physiology, Medical School, Centre for Neuroscience, Szentágothai Research Centre, University of Pécs, H7624 Pécs, Hungary; (T.C.); (B.T.); (C.L.F.); (P.C.); (D.V.)
- Laboratory of Behavioral and Stress Studies, Institute of Experimental Medicine, H1083 Budapest, Hungary;
- János Szentágothai School of Neurosciences, Semmelweis University, H1085 Budapest, Hungary
| | - Pedro Correia
- Institute of Physiology, Medical School, Centre for Neuroscience, Szentágothai Research Centre, University of Pécs, H7624 Pécs, Hungary; (T.C.); (B.T.); (C.L.F.); (P.C.); (D.V.)
- Laboratory of Behavioral and Stress Studies, Institute of Experimental Medicine, H1083 Budapest, Hungary;
- János Szentágothai School of Neurosciences, Semmelweis University, H1085 Budapest, Hungary
| | - Eszter Sipos
- Laboratory of Behavioral and Stress Studies, Institute of Experimental Medicine, H1083 Budapest, Hungary;
| | - Dorottya Várkonyi
- Institute of Physiology, Medical School, Centre for Neuroscience, Szentágothai Research Centre, University of Pécs, H7624 Pécs, Hungary; (T.C.); (B.T.); (C.L.F.); (P.C.); (D.V.)
- Laboratory of Behavioral and Stress Studies, Institute of Experimental Medicine, H1083 Budapest, Hungary;
| | - Zsuzsanna E. Tóth
- Laboratory of Neuroendocrinology and in Situ Hybridization, Department of Anatomy, Histology and Embryology, Semmelweis University, H1094 Budapest, Hungary;
| | - Fanni Dóra
- Human Brain Tissue Bank, Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology, Semmelweis University, H1094 Budapest, Hungary;
| | - Árpád Dobolyi
- Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Eötvös Loránd University, H1117 Budapest, Hungary;
| | - Dóra Zelena
- Institute of Physiology, Medical School, Centre for Neuroscience, Szentágothai Research Centre, University of Pécs, H7624 Pécs, Hungary; (T.C.); (B.T.); (C.L.F.); (P.C.); (D.V.)
- Laboratory of Behavioral and Stress Studies, Institute of Experimental Medicine, H1083 Budapest, Hungary;
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Wang Y, Song Y, Dai Y, Li X, Xie J, Luo J, Yang C, Fan P, Xiao G, Luo Y, Wang Y, Li Y, Cai X. The burst of electrophysiological signals in the suprachiasmatic nucleus of mouse during the arousal detected by microelectrode arrays. Front Bioeng Biotechnol 2022; 10:970726. [PMID: 36110317 PMCID: PMC9468547 DOI: 10.3389/fbioe.2022.970726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 08/10/2022] [Indexed: 11/13/2022] Open
Abstract
The neural mechanisms of torpor have essential reference significance for medical methods and long-term manned space. Changes in electrophysiology of suprachiasmatic nucleus (SCN) conduce to revealing the neural mechanisms from the torpor to arousal. Due to the lower physiology state during the torpor, it is a challenge to detect neural activities in vivo on freely behaving mice. Here, we introduced a multichannel microelectrode array (MEA) for real-time detection of local field potential (LFP) and action potential (spike) in the SCN in induced torpor mice. Meanwhile, core body temperature and behaviors of mice were recorded for further analysis. Platinum nanoparticles (PtNPs) and Nafion membrane modified MEA has a lower impedance (16.58 ± 3.93 kΩ) and higher signal-to-noise ratio (S/N = 6.1). We found that from torpor to arousal, the proportion of theta frequency bands of LFPs increased, spike firing rates rapidly increased. These results could all be characteristic information of arousal, supported by the microscopic neural activity promoting arousal in mice. MEA displayed real-time dynamic changes of neuronal activities in the SCN, which was more helpful to analyze and understand neural mechanisms of torpor and arousal. Our study provided a factual basis for the neural state in SCN of induced non-hibernating animals, which was helpful for the application of clinics and spaceflight.
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Affiliation(s)
- Yiding Wang
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Yilin Song
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Yuchuan Dai
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Xinrong Li
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Jingyu Xie
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Jinping Luo
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Chao Yang
- China Astronaut Research and Training Center, Beijing, China
| | - Penghui Fan
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Guihua Xiao
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Yan Luo
- Department of Anesthesiology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Ying Wang
- Department of Anesthesiology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- *Correspondence: Xinxia Cai, ; Yinghui Li, ; Ying Wang,
| | - Yinghui Li
- China Astronaut Research and Training Center, Beijing, China
- *Correspondence: Xinxia Cai, ; Yinghui Li, ; Ying Wang,
| | - Xinxia Cai
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, China
- *Correspondence: Xinxia Cai, ; Yinghui Li, ; Ying Wang,
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Assari S. Stronger Association between Nucleus Accumbens Density and Body Mass Index in Low-Income and African American Children. RESEARCH IN HEALTH SCIENCE 2020; 5:107-120. [PMID: 33294757 DOI: 10.22158/rhs.v5n2p107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND The nucleus accumbens' (NAc) size, function, and density influence individuals' body mass index (BMI). However, little is known about racial and socioeconomic status (SES) differences in the role of NAc density as a predictor of childhood BMI. OBJECTIVES We used the Adolescent Brain Cognitive Development (ABCD) data to investigate racial and SES differences in the effect of NAc density on childhood BMI. METHODS This cross-sectional study included 9497 children between ages 9 and 10. Mixed-effects regression models were used to analyze the data. The predictor variable was NAc density measured using diffusion MRI (dMRI). The outcome variable was BMI, operationalized as a continuous variable. Covariates included sex, age, ethnicity, family structure, and parental education. Race (White, African American, Asian, and Other/mixed) and household income (< 50k, 50-100 k, and 100+ k) were the moderators. RESULTS High NAc diffusion tension (density) was predictive of higher BMI, net of covariates. However, the positive association between NAc density and BMI was stronger in African Americans than in White, and in low-income than in high-income children. CONCLUSIONS Our findings suggest that although high NAc has implications for children's BMI, this effect varies across racial and SES groups. More research should be performed on the role of obesogenic environments in altering the effect of NAc on childhood BMI.
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Affiliation(s)
- Shervin Assari
- Department of Family Medicine, Charles R. Drew University of Medicine and Science, Los Angeles, CA, USA.,Department of Urban Public Health, Charles R. Drew University of Medicine and Science, Los Angeles, CA, USA
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Grippo RM, Purohit AM, Zhang Q, Zweifel LS, Güler AD. Direct Midbrain Dopamine Input to the Suprachiasmatic Nucleus Accelerates Circadian Entrainment. Curr Biol 2017; 27:2465-2475.e3. [PMID: 28781050 DOI: 10.1016/j.cub.2017.06.084] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 06/02/2017] [Accepted: 06/30/2017] [Indexed: 01/09/2023]
Abstract
Dopamine (DA) neurotransmission controls behaviors important for survival, including voluntary movement, reward processing, and detection of salient events, such as food or mate availability. Dopaminergic tone also influences circadian physiology and behavior. Although the evolutionary significance of this input is appreciated, its precise neurophysiological architecture remains unknown. Here, we identify a novel, direct connection between the DA neurons of the ventral tegmental area (VTA) and the suprachiasmatic nucleus (SCN). We demonstrate that D1 dopamine receptor (Drd1) signaling within the SCN is necessary for properly timed resynchronization of activity rhythms to phase-shifted light:dark cycles and that elevation of DA tone through selective activation of VTA DA neurons accelerates photoentrainment. Our findings demonstrate a previously unappreciated role for direct DA input to the master circadian clock and highlight the importance of an evolutionarily significant relationship between the circadian system and the neuromodulatory circuits that govern motivational behaviors.
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Affiliation(s)
- Ryan M Grippo
- Department of Biology, University of Virginia, 485 McCormick Road, Charlottesville, VA 22904, USA
| | - Aarti M Purohit
- Department of Biology, University of Virginia, 485 McCormick Road, Charlottesville, VA 22904, USA
| | - Qi Zhang
- Department of Biology, University of Virginia, 485 McCormick Road, Charlottesville, VA 22904, USA
| | - Larry S Zweifel
- Departments of Pharmacology and Psychiatry and Behavioral Sciences, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Ali D Güler
- Department of Biology, University of Virginia, 485 McCormick Road, Charlottesville, VA 22904, USA; Department of Neuroscience, School of Medicine, University of Virginia, 409 Lane Road, Charlottesville, VA 22908, USA.
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Powell SB, Newman HA, Pendergast JF, Lewis MH. A rodent model of spontaneous stereotypy: initial characterization of developmental, environmental, and neurobiological factors. Physiol Behav 1999; 66:355-63. [PMID: 10336165 DOI: 10.1016/s0031-9384(98)00303-5] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Stereotypies are patterns of motor behavior that are repetitive, excessive, topographically invariant, and that lack any obvious function or purpose. In humans, stereotyped behaviors are associated with psychiatric, neurological, and developmental disorders. In animals, stereotypy has been frequently associated with adverse environmental circumstances and often related to alterations in striatal dopamine. To assess the development of stereotyped behaviors and to test the hypothesis that these behaviors are associated with environmental restriction, deer mice were housed in either standard laboratory cages or larger, enriched cages, and the development of stereotypy was followed from weaning over a 17-week period. Standard-caged deer mice engaged in stereotyped behaviors at a higher rate and developed these behaviors more quickly when compared to animals in enriched caging. Additionally, enriched caging was associated with higher rates of patterned running, whereas jumping and backward somersaulting were typically observed in standard cages. In addition, there was a significant effect of litter, but no effect of sex or cage, on the time to develop stereotypy. No differences were found in the density of either striatal D1 or D2 dopamine receptors or the concentration of striatal dopamine or its metabolites as a function of rearing condition or as a function of whether the animals developed stereotypy. These results characterize the development of stereotypies in this species, demonstrate the importance of environmental conditions in the genesis of stereotypy, and suggest that alterations in striatal dopamine content or dopamine receptor density do not account for the expression of stereotyped behaviors in this model.
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Affiliation(s)
- S B Powell
- Department of Psychiatry, University of Florida, Gainesville 32610, USA.
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Phelix CF, Adai DM, Cantu C, Chen H, Wayner MJ. Immunohistochemical demonstration of serotonin-containing axons in the hypothalamus of the white-footed mouse, Peromyscus leucopus. Brain Res 1998; 808:197-219. [PMID: 9767166 DOI: 10.1016/s0006-8993(98)00796-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The wild white-footed mouse, Peromyscus leucopus, is commonly used for photoperiod studies utilizing physiological, behavioral, and other biological measures indicative of hypothalamic functions. Indoleamines, like melatonin and serotonin, are implicated in regulating these hypothalamic functions. Although neurochemical analyses of hypothalamic serotonin and its receptors have been reported for this species, the relevant neuroanatomy of the serotonin system within mouse hypothalamus has not been studied. A sensitive immunohistochemical method was used to detect serotonin within axons of coronal sections of formaldehyde fixed forebrain from P. leucopus. Large, medium and small diameter serotonin axons were evaluated in most regions, or nuclei, of the hypothalamus rostral to the mammillary region. A fourth type of serotonin axon was observed to have morphology characteristic of terminal arbors. The density of serotonin axons ranged from no staining to very high density similar to other species for which reports exist, i.e., rat, cat, and monkey. The ventromedial hypothalamic nucleus had distinctively lesser density of serotonin axons in this mouse than other species. Evidence of terminal arborization in hypothalamic nuclei and regions was evident. Neuroendocrine, autonomic, and behavioral functions of the hypothalamus are suggested to be regulated by input from serotonin terminals in this wild species of mouse, in correlation with receptor localization as reported by others.
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Affiliation(s)
- C F Phelix
- Division of Life Sciences, The University of Texas at San Antonio, 6900 North Loop 1604 West, San Antonio, TX 78249, USA.
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Novak CM, Nunez AA. Tyrosine hydroxylase- and/or aromatic L-amino acid decarboxylase-containing cells in the suprachiasmatic nucleus of the Syrian hamster (Mesocricetus auratus). J Chem Neuroanat 1998; 14:87-94. [PMID: 9625353 DOI: 10.1016/s0891-0618(97)10019-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Catecholamines, including dopamine (DA), affect the activity of cells in the suprachiasmatic nucleus (SCN) of the hypothalamus, the principal circadian clock in mammals. This study examined the distribution of dopaminergic cells in the SCN of the male Syrian hamster, using both single- and double-label immunocytochemistry for tyrosine hydroxylase (TH), the rate-limiting enzyme in DA synthesis and for aromatic L-amino acid decarboxylase (AADC), the second enzyme needed to produce DA. Some neurons immunopositive for TH (TH + ) were found in the SCN, but most of the TH + cells of the region were located just outside the borders of the nucleus, as defined by pyronin Y staining. In the SCN, 91% of these cells were also immunopositive for AADC and thus, likely to be dopaminergic. Cells positive for AADC, many of which were not TH +, were found throughout the SCN, with the highest concentration seen in the ventral aspects of the nucleus. Cells containing AADC, but lacking TH may synthesize products other than DA, such as trace amines. These anatomical observations suggest that local neurons that produce DA and perhaps trace amines, may play a role in SCN function and in the neural control of circadian rhythms.
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Affiliation(s)
- C M Novak
- Department of Psychology, Michigan State University, East Lansing 48824-1117, USA
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Horowitz JM, Horrigan DJ. Hibernation in Mammals: Central Nervous System Function. Compr Physiol 1996. [DOI: 10.1002/cphy.cp040123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Hulihan-Giblin BA, Pivorun EB, Goldman D. Diurnal rhythms of 5-HT1A and 5-HT2 receptor binding in euthermic and torpor prone deermice, Peromyscus maniculatus. Pharmacol Biochem Behav 1993; 45:785-9. [PMID: 8415817 DOI: 10.1016/0091-3057(93)90121-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Deermice display both spontaneous and induced daily torpor bouts, attaining minimum body temperatures of 15-20 degrees C. There is evidence that brain serotonin may be involved in the initiation and/or maintenance of torpor. Inhibition of serotonin [5-hydroxytryptamine (5-HT)] synthesis markedly reduces the duration and depth of torpor. Because a certain percentage of deermice will not enter torpor under any circumstances, we were able to compare 5-HT receptor subtypes in deermice that readily enter into torpor (TP) and in non-torpor prone (NTP) animals. Deermice were trapped in the wild and subjected to food rationing and low ambient temperature and then sacrificed either in a normothermic or torpid state at 11:00 p.m. or 11:00 a.m. Whole brain was assayed for 5-HT1A and 5-HT2 receptor differences using [3H]8-OH-DPAT and [3H]ketanserin, respectively. The Bmax values for 5-HT1A receptors were significantly greater in both TP and NTP animals sacrificed at 11:00 p.m. compared to animals sacrificed at 11:00 a.m. In contrast, the density of 5-HT2 receptors was significantly greater in animals sacrificed at 11:00 a.m. compared to animals sacrificed at 11:00 p.m. This is consistent with the opposing functions of these receptors in the regulation of temperature and sleep. The affinity (Kd) of each receptor was unchanged. A comparison of TP and NTP animals sacrificed at the same time of day revealed no significant differences in either Bmax or in Kd values, indicating that differences in 5-HT1A and 5-HT2 receptors may not explain the heterogeneity of deermice in their ability to enter torpor.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- B A Hulihan-Giblin
- Laboratory of Neurogenetics, NIAAA, NIH Clinical Center, Bethesda, MD 20892
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Kaminski D, Weiner N, Sturm G, Wesemann W. Modulation of serotonin binding sites in the brain of the Djungarian hamster, Phodopus sungorus, during adaptation to a short photoperiod. J Neural Transm (Vienna) 1993; 92:159-71. [PMID: 8369107 DOI: 10.1007/bf01244875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
During the physiological adaptation of the Djungarian hamster, Phodopus sungorus, to a short photoperiod in autumn the modulation of specific serotonin (5-HT) binding sites of synaptic membranes was investigated in two brain regions, i.e. cerebral cortex and basal brain (CNS without cerebral cortex, cerebellum, pineal gland, and spinal cord). The radioligands [3H]5-HT and [3H]ketanserin were used to characterize total 5-HT1 and 5-HT2 binding sites, respectively. An increase of 5-HT1 and 5-HT2 binding sites was observed in both brain regions within 14 days after reduction of the photoperiod from a 14:10 h light/dark (l/d) cycle to an 8:16 h l/d cycle. The increase was still present after 56 days of the short photoperiod. Binding kinetics assayed after 4 days of the short photoperiod show that maximal specific binding of [3H]5-HT and [3H]ketanserin was increased, while dissociation constants (KD) were not changed. The membrane anisotropy of synaptic membranes, measured by fluorescence polarization, was reduced transiently during the early part of the adaptation. Neither the phospholipids nor the mole ratio of cholesterol to phospholipids were significantly affected by adaptation to short photoperiod. The results suggest an important role of the central nervous 5-HT system in the physiological adaptation of the Djungarian hamster to a short photoperiod.
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Affiliation(s)
- D Kaminski
- Abteilung Neurochemie, Philipps-Universität, Marburg, Federal Republic of Germany
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Hulihan-Giblin BA, Park YD, Pivorun EB, Goldman D. Regional analysis of 5-HT1A receptors in two species of Peromyscus. Pharmacol Biochem Behav 1993; 45:143-5. [PMID: 8516353 DOI: 10.1016/0091-3057(93)90097-d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Two species of deer-mice, Peromyscus maniculatus (P. man) and Peromyscus leucopus (P. leu), were compared for differences in 5-hydroxytryptamine1A (5-HT1A) receptor number and affinity. Both species enter into torpor; however, P. man enters spontaneous torpor with a higher frequency and for a longer duration than P. leu. Further, compared to P. leu a higher percentage of P. man exhibit daily torpor. Deer mice can be induced to enter torpor by a reduction in food supply, shortened photoperiods, and decreasing ambient temperature. Under these conditions, P. man enters into torpor more frequently, for longer durations, and with a higher percentage of individuals as compared to P. leu. [3H]8-OH-DPAT was used to label 5-HT1A brain receptors in three brain regions: the frontal cortex, brainstem, and striatum. In addition, the hypothalamus and hippocampus were examined for 5-HT1A receptor differences; however, no measurable specific binding could be determined in these regions. In the frontal cortex, the Bmax values were significantly lower in P. man compared to P. leu. There were no significant differences in the Bmax values in the striatum and brainstem between P. man and P. leu. Further, there were no significant differences in the Kd values between the two species in any of the brain regions examined. The absence of any difference in receptor number or affinity in any of the brain regions examined, except the cortex, suggests that the 5-HT1A receptor is most likely not involved in a more efficient pathway to torpor.
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Affiliation(s)
- B A Hulihan-Giblin
- Laboratory of Neurogenetics, National Institute on Alcoholism and Alcohol Abuse, National Institutes of Health, Bethesda, MD 20892
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Lin LH, Pivorun EB. Hypothalamic monoamines and their metabolites in the deermouse, Peromyscus maniculatus, during daily torpor. J Neural Transm (Vienna) 1990; 79:11-8. [PMID: 2297395 DOI: 10.1007/bf01250995] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Deermice, subjected to food rationing, an ambient temperature below thermal neutrality and short photoperiod, were sacrificed in euthermia or during daily torpor. Hypothalamic monoamine and metabolite levels were quantified by HPLC with electrochemical detection. Significant elevations in the levels (pg/microgram protein) of dopamine, 3,4-dihydroxyphenylacetic acid, and homovanillic acid were noted in the torpid animals. The concentrations of norepinephrine and serotonin displayed no significant alterations between the euthermic and torpid states. However, the serotonin metabolite, 5-hydroxyindole-3-acetic acid, was elevated by almost 300%. These data suggest that an increase in activity of the hypothalamic serotonergic and dopaminergic systems occurs during daily torpor in the deermouse.
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Affiliation(s)
- L H Lin
- Department of Biological Sciences, Clemson University, South Carolina
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