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Cea Salazar VI, Perez MD, Robison AJ, Trainor BC. Impacts of sex differences on optogenetic, chemogenetic, and calcium-imaging tools. Curr Opin Neurobiol 2024; 84:102817. [PMID: 38042130 DOI: 10.1016/j.conb.2023.102817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/05/2023] [Accepted: 11/06/2023] [Indexed: 12/04/2023]
Abstract
Technical innovation in neuroscience introduced powerful tools for measuring and manipulating neuronal activity via optical, chemogenetic, and calcium-imaging tools. These tools were initially tested primarily in male animals but are now increasingly being used in females as well. In this review, we consider how these tools may work differently in males and females. For example, we review sex differences in the metabolism of chemogenetic ligands and their downstream signaling effects. Optical tools more directly alter depolarization or hyperpolarization of neurons, but biological sex and gonadal hormones modulate synaptic inputs and intrinsic excitability. We review studies demonstrating that optogenetic manipulations are sometimes consistent across the rodent estrous cycle but within certain circuits; manipulations can vary across the ovarian cycle. Finally, calcium-imaging methods utilize genetically encoded calcium indicators to measure neuronal activity. Testosterone and estradiol can directly modulate calcium influx, and we consider these implications for interpreting the results of calcium-imaging studies. Together, our findings suggest that these neuroscientific tools may sometimes work differently in males and females and that users should be aware of these differences when applying these methods.
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Affiliation(s)
| | - Melvin D Perez
- Department of Physiology, University of California, Davis, CA 95616, USA
| | - A J Robison
- Department of Psychology, University of California, Davis, CA 95616, USA
| | - Brian C Trainor
- Neuroscience Graduate Group, University of California, Davis, CA 95616, USA; Department of Physiology, Michigan State University, East Lansing, MI 48824, USA.
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2
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Scarpa GB, Starrett JR, Li GL, Brooks C, Morohashi Y, Yazaki-Sugiyama Y, Remage-Healey L. Estrogens rapidly shape synaptic and intrinsic properties to regulate the temporal precision of songbird auditory neurons. Cereb Cortex 2022; 33:3401-3420. [PMID: 35849820 PMCID: PMC10068288 DOI: 10.1093/cercor/bhac280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 01/14/2023] Open
Abstract
Sensory neurons parse millisecond-variant sound streams like birdsong and speech with exquisite precision. The auditory pallial cortex of vocal learners like humans and songbirds contains an unconventional neuromodulatory system: neuronal expression of the estrogen synthesis enzyme aromatase. Local forebrain neuroestrogens fluctuate when songbirds hear a song, and subsequently modulate bursting, gain, and temporal coding properties of auditory neurons. However, the way neuroestrogens shape intrinsic and synaptic properties of sensory neurons remains unknown. Here, using a combination of whole-cell patch clamp electrophysiology and calcium imaging, we investigate estrogenic neuromodulation of auditory neurons in a region resembling mammalian auditory association cortex. We found that estradiol rapidly enhances the temporal precision of neuronal firing via a membrane-bound G-protein coupled receptor and that estradiol rapidly suppresses inhibitory synaptic currents while sparing excitation. Notably, the rapid suppression of intrinsic excitability by estradiol was predicted by membrane input resistance and was observed in both males and females. These findings were corroborated by analysis of in vivo electrophysiology recordings, in which local estrogen synthesis blockade caused acute disruption of the temporal correlation of song-evoked firing patterns. Therefore, on a modulatory timescale, neuroestrogens alter intrinsic cellular properties and inhibitory neurotransmitter release to regulate the temporal precision of higher-order sensory neurons.
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Affiliation(s)
- Garrett B Scarpa
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, 639 N. Pleasant St., Amherst, MA 01003, United States
| | - Joseph R Starrett
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, 639 N. Pleasant St., Amherst, MA 01003, United States
| | - Geng-Lin Li
- Department of Otorhinolaryngology, Eye and ENT Hospital, Fudan University, 83 Fenyang Rd, Xuhui District, Shanghai 200031, China
| | - Colin Brooks
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, 639 N. Pleasant St., Amherst, MA 01003, United States
| | - Yuichi Morohashi
- Okinawa Institute of Science and Technology (OIST) Graduate University, 1919-1 Tancha, Onna, Kunigami District, Okinawa, Japan
| | - Yoko Yazaki-Sugiyama
- Okinawa Institute of Science and Technology (OIST) Graduate University, 1919-1 Tancha, Onna, Kunigami District, Okinawa, Japan
| | - Luke Remage-Healey
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, 639 N. Pleasant St., Amherst, MA 01003, United States
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3
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Hernández-Vivanco A, Cano-Adamuz N, Sánchez-Aguilera A, González-Alonso A, Rodríguez-Fernández A, Azcoitia Í, de la Prida LM, Méndez P. Sex-specific regulation of inhibition and network activity by local aromatase in the mouse hippocampus. Nat Commun 2022; 13:3913. [PMID: 35798748 PMCID: PMC9262915 DOI: 10.1038/s41467-022-31635-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 06/27/2022] [Indexed: 11/15/2022] Open
Abstract
Cognitive function relies on a balanced interplay between excitatory and inhibitory neurons (INs), but the impact of estradiol on IN function is not fully understood. Here, we characterize the regulation of hippocampal INs by aromatase, the enzyme responsible for estradiol synthesis, using a combination of molecular, genetic, functional and behavioral tools. The results show that CA1 parvalbumin-expressing INs (PV-INs) contribute to brain estradiol synthesis. Brain aromatase regulates synaptic inhibition through a mechanism that involves modification of perineuronal nets enwrapping PV-INs. In the female brain, aromatase modulates PV-INs activity, the dynamics of network oscillations and hippocampal-dependent memory. Aromatase regulation of PV-INs and inhibitory synapses is determined by the gonads and independent of sex chromosomes. These results suggest PV-INs are mediators of estrogenic regulation of behaviorally-relevant activity. Using a combination of molecular, genetic, functional and behavioural tools, this study describes the impact of brain synthesized estrogen in inhibitory neuronal function, network oscillations and hippocampal dependent memory.
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Affiliation(s)
| | | | - Alberto Sánchez-Aguilera
- Instituto Cajal (CSIC), Av Dr. Arce 37, 28002, Madrid, Spain.,Department of Physiology, Faculty of Medicine, Universidad Complutense de Madrid IdISSC, Avda Complutense s/n, 28040, Madrid, Spain
| | | | | | - Íñigo Azcoitia
- Department of Cell Biology, Universidad Complutense de Madrid, C José Antonio Nováis 12, 28040, Madrid, Spain.,Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Pablo Méndez
- Instituto Cajal (CSIC), Av Dr. Arce 37, 28002, Madrid, Spain.
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4
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Kraynak M, Willging MM, Kuehlmann AL, Kapoor AA, Flowers MT, Colman RJ, Levine JE, Abbott DH. Aromatase Inhibition Eliminates Sexual Receptivity Without Enhancing Weight Gain in Ovariectomized Marmoset Monkeys. J Endocr Soc 2022; 6:bvac063. [PMID: 35592515 PMCID: PMC9113444 DOI: 10.1210/jendso/bvac063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Indexed: 11/19/2022] Open
Abstract
Context Ovarian estradiol supports female sexual behavior and metabolic function. While ovariectomy (OVX) in rodents abolishes sexual behavior and enables obesity, OVX in nonhuman primates decreases, but does not abolish, sexual behavior, and inconsistently alters weight gain. Objective We hypothesize that extra-ovarian estradiol provides key support for both functions, and to test this idea, we employed aromatase inhibition to eliminate extra-ovarian estradiol biosynthesis and diet-induced obesity to enhance weight gain. Methods Thirteen adult female marmosets were OVX and received (1) estradiol-containing capsules and daily oral treatments of vehicle (E2; n = 5); empty capsules and daily oral treatments of either (2) vehicle (VEH, 1 mL/kg, n = 4), or (3) letrozole (LET, 1 mg/kg, n = 4). Results After 7 months, we observed robust sexual receptivity in E2, intermediate frequencies in VEH, and virtually none in LET females (P = .04). By contrast, few rejections of male mounts were observed in E2, intermediate frequencies in VEH, and high frequencies in LET females (P = .04). Receptive head turns were consistently observed in E2, but not in VEH and LET females. LET females, alone, exhibited robust aggressive rejection of males. VEH and LET females demonstrated increased % body weight gain (P = .01). Relative estradiol levels in peripheral serum were E2 >>> VEH > LET, while those in hypothalamus ranked E2 = VEH > LET, confirming inhibition of local hypothalamic estradiol synthesis by letrozole. Conclusion Our findings provide the first evidence for extra-ovarian estradiol contributing to female sexual behavior in a nonhuman primate, and prompt speculation that extra-ovarian estradiol, and in particular neuroestrogens, may similarly regulate sexual motivation in other primates, including humans.
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Affiliation(s)
- Marissa Kraynak
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Molly M Willging
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Center for Women’s Health, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Alex L Kuehlmann
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Amita A Kapoor
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Matthew T Flowers
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Ricki J Colman
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Jon E Levine
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - David H Abbott
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA
- Endocrinology-Reproductive Physiology Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Madison, WI 53715, USA
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5
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Storman EM, Liu NJ, Gintzler AR. Relevance of c-Src and protein phosphatase 2A to aromatase activity: Evidence of an acute self-regulating oestrogenic signalling complex in rat central nervous system. J Neuroendocrinol 2022; 34:e13089. [PMID: 35043508 PMCID: PMC9038631 DOI: 10.1111/jne.13089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/30/2021] [Accepted: 12/30/2021] [Indexed: 12/27/2022]
Abstract
We previously reported that aromatase protein levels do not parallel aromatase enzyme activity. This suggests that oestrogenic signalling may be modulated via post-translational modification of aromatase protein. The tyrosine and serine phosphorylation state of aromatase are known to influence its activity. To investigate the possible relevance of aromatase phosphorylation to the incongruity observed between aromatase protein and its activity, we explored interactions between aromatase and the tyrosine kinase c-Src and the serine protein phosphatases 2A and 5 (PP2A and PP5), as well as the relationship between levels of tyrosine-phosphorylated aromatase and the extrapolated aromatase activity. We found that (a) hypothalamic aromatase was significantly more heavily tyrosine-phosphorylated than spinal aromatase; (b) aromatase was oligomerized with c-Src and PP2A/PP5, potentially activating aromatase via tyrosine-phosphorylation and serine-dephosphorylation; (c) the associations of c-Src and PP2A/PP5 with hypothalamic aromatase were substantially greater than with spinal aromatase; and (d) aromatase, oestrogen receptor α, PP2A, and c-Src were present in a common membrane oligomer. The existence of c-Src and PP2A in an oligomer that also contains aromatase and membrane oestrogen receptor α (and presumably other signalling molecules) indicates the presence in the CNS of a potentially self-regulating oestrogenic signalling unit. The degree to which such a complex operates autonomously and the regulatory factors thereof are likely to have substantial physiological implications and clinical relevance.
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Affiliation(s)
- Emiliya M Storman
- Department of Obstetrics and Gynecology, State University of New York, Downstate Health Sciences University, Brooklyn, New York, USA
| | - Nai-Jiang Liu
- Department of Obstetrics and Gynecology, State University of New York, Downstate Health Sciences University, Brooklyn, New York, USA
| | - Alan R Gintzler
- Department of Obstetrics and Gynecology, State University of New York, Downstate Health Sciences University, Brooklyn, New York, USA
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6
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Taxier LR, Gross KS, Frick KM. Oestradiol as a neuromodulator of learning and memory. Nat Rev Neurosci 2020; 21:535-550. [PMID: 32879508 DOI: 10.1038/s41583-020-0362-7] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2020] [Indexed: 12/24/2022]
Abstract
Although hormones such as glucocorticoids have been broadly accepted in recent decades as general neuromodulators of memory processes, sex steroid hormones such as the potent oestrogen 17β-oestradiol have been less well recognized by the scientific community in this capacity. The predominance of females in studies of oestradiol and memory and the general (but erroneous) perception that oestrogens are 'female' hormones have probably prevented oestradiol from being more widely considered as a key memory modulator in both sexes. Indeed, although considerable evidence supports a crucial role for oestradiol in regulating learning and memory in females, a growing body of literature indicates a similar role in males. This Review discusses the mechanisms of oestradiol signalling and provides an overview of the effects of oestradiol on spatial, object recognition, social and fear memories. Although the primary focus is on data collected in females, effects of oestradiol on memory in males will be discussed, as will sex differences in the molecular mechanisms that regulate oestrogenic modulation of memory, which may have important implications for the development of future cognitive therapeutics.
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Affiliation(s)
- Lisa R Taxier
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Kellie S Gross
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Karyn M Frick
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
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7
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Delhez A, Lefebvre P, Péqueux C, Malgrange B, Delacroix L. Auditory function and dysfunction: estrogen makes a difference. Cell Mol Life Sci 2020; 77:619-635. [PMID: 31522250 PMCID: PMC11105012 DOI: 10.1007/s00018-019-03295-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 08/30/2019] [Accepted: 09/05/2019] [Indexed: 01/09/2023]
Abstract
Estrogen is the major female hormone involved in reproductive functions, but it also exerts a variety of additional roles in non-reproductive organs. In this review, we highlight the preclinical and clinical studies that have pointed out sex differences and estrogenic influence on audition. We also describe the experimental evidences supporting a protective role of estrogen towards acquired forms of hearing loss. Although a high level of endogenous estrogen is associated with a better hearing function, hormonal treatments at menopause have provided contradictory outcomes. The various factors that are likely to explain these discrepancies include the treatment regimen as well as the hormonal status and responsiveness of the patients. The complexity of estrogen signaling is being untangled and many downstream effectors of its genomic and non-genomic actions have been identified in other systems. Based on these advances and on the common physio-pathological events that underlie age-related, drug or noise-induced hearing loss, we discuss potential mechanisms for their protective actions in the cochlea.
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Affiliation(s)
- Amandine Delhez
- GIGA-Neurosciences, Developmental Neurobiology Unit, University of Liege, Liege, Belgium
- Department of ENT, CHU de Liege, Liege, Belgium
| | | | - Christel Péqueux
- GIGA-Cancer, Laboratory of Tumors Biology and Development, University of Liege, Liege, Belgium
| | - Brigitte Malgrange
- GIGA-Neurosciences, Developmental Neurobiology Unit, University of Liege, Liege, Belgium
| | - Laurence Delacroix
- GIGA-Neurosciences, Developmental Neurobiology Unit, University of Liege, Liege, Belgium.
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8
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Duncan KA. Estrogen Formation and Inactivation Following TBI: What we Know and Where we Could go. Front Endocrinol (Lausanne) 2020; 11:345. [PMID: 32547495 PMCID: PMC7272601 DOI: 10.3389/fendo.2020.00345] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 05/04/2020] [Indexed: 01/27/2023] Open
Abstract
Traumatic brain injury (TBI) is responsible for various neuronal and cognitive deficits as well as psychosocial dysfunction. Characterized by damage inducing neuroinflammation, this response can cause an acute secondary injury that leads to widespread neurodegeneration and loss of neurological function. Estrogens decrease injury induced neuroinflammation and increase cell survival and neuroprotection and thus are a potential target for use following TBI. While much is known about the role of estrogens as a neuroprotective agent following TBI, less is known regarding their formation and inactivation following damage to the brain. Specifically, very little is known surrounding the majority of enzymes responsible for the production of estrogens. These estrogen metabolizing enzymes (EME) include aromatase, steroid sulfatase (STS), estrogen sulfotransferase (EST/SULT1E1), and some forms of 17β-hydroxysteroid dehydrogenase (HSD17B) and are involved in both the initial conversion and interconversion of estrogens from precursors. This article will review and offer new prospective and ideas on the expression of EMEs following TBI.
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9
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Devine MJ, Kittler JT. Mitochondria at the neuronal presynapse in health and disease. Nat Rev Neurosci 2019; 19:63-80. [PMID: 29348666 DOI: 10.1038/nrn.2017.170] [Citation(s) in RCA: 333] [Impact Index Per Article: 66.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Synapses enable neurons to communicate with each other and are therefore a prerequisite for normal brain function. Presynaptically, this communication requires energy and generates large fluctuations in calcium concentrations. Mitochondria are optimized for supplying energy and buffering calcium, and they are actively recruited to presynapses. However, not all presynapses contain mitochondria; thus, how might synapses with and without mitochondria differ? Mitochondria are also increasingly recognized to serve additional functions at the presynapse. Here, we discuss the importance of presynaptic mitochondria in maintaining neuronal homeostasis and how dysfunctional presynaptic mitochondria might contribute to the development of disease.
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Affiliation(s)
- Michael J Devine
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Josef T Kittler
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
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10
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Possible Existence of the Hypothalamic-Pituitary-Hippocampal (HPH) Axis: A Reciprocal Relationship Between Hippocampal Specific Neuroestradiol Synthesis and Neuroblastosis in Ageing Brains with Special Reference to Menopause and Neurocognitive Disorders. Neurochem Res 2019; 44:1781-1795. [PMID: 31254250 DOI: 10.1007/s11064-019-02833-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 05/13/2019] [Accepted: 06/19/2019] [Indexed: 12/18/2022]
Abstract
The hippocampus-derived neuroestradiol plays a major role in neuroplasticity, independent of circulating estradiol that originates from gonads. The response of hypothalamus-pituitary regions towards the synthesis of neuroestradiol in the hippocampus is an emerging scientific concept in cognitive neuroscience. Hippocampal plasticity has been proposed to be regulated via neuroblasts, a major cellular determinant of functional neurogenesis in the adult brain. Defects in differentiation, integration and survival of neuroblasts in the hippocampus appear to be an underlying cause of neurocognitive disorders. Gonadotropin receptors and steroidogenic enzymes have been found to be expressed in neuroblasts in the hippocampus of the brain. However, the reciprocal relationship between hippocampal-specific neuroestradiol synthesis along neuroblastosis and response of pituitary based feedback regulation towards regulation of estradiol level in the hippocampus have not completely been ascertained. Therefore, this conceptual article revisits (1) the cellular basis of neuroestradiol synthesis (2) a potential relationship between neuroestradiol synthesis and neuroblastosis in the hippocampus (3) the possible involvement of aberrant neuroestradiol production with mitochondrial dysfunctions and dyslipidemia in menopause and adult-onset neurodegenerative disorders and (4) provides a hypothesis for the possible existence of the hypothalamic-pituitary-hippocampal (HPH) axis in the adult brain. Eventually, understanding the regulation of hippocampal neurogenesis by abnormal levels of neuroestradiol concentration in association with the feedback regulation of HPH axis might provide additional cues to establish a neuroregenerative therapeutic management for mood swings, depression and cognitive decline in menopause and neurocognitive disorders.
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11
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Koss WA, Frick KM. Activation of androgen receptors protects intact male mice from memory impairments caused by aromatase inhibition. Horm Behav 2019; 111:96-104. [PMID: 30653980 PMCID: PMC6527464 DOI: 10.1016/j.yhbeh.2019.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/21/2018] [Accepted: 01/10/2019] [Indexed: 12/17/2022]
Abstract
Although 17β-estradiol (E2) is known to regulate hippocampal function, the specific contributions of hippocampally-synthesized E2 remain unclear. Infusion of the aromatase inhibitor letrozole into the dorsal hippocampus (DH) of ovariectomized mice disrupts object recognition and object placement memory consolidation, suggesting that DH-synthesized E2 is essential for memory. However, the role of DH-synthesized E2 in memory among male rodents is unknown. Here, we examined effects of aromatase inhibition on memory consolidation in male mice. Intact and gonadectomized mice were infused with vehicle or letrozole into the DH immediately post-training in object placement and object recognition tasks. Letrozole blocked memory in both tasks among gonadectomized males only, suggesting that circulating androgens, or a rise in hippocampal androgens due to aromatase inhibition, may support memory consolidation in intact males. To test this hypothesis, intact males were infused with the androgen receptor antagonist flutamide into the DH after object training. A dose-dependent impairment was observed in both tasks, indicating that blocking androgen signaling can impair memory consolidation. To test if hippocampal androgen receptor activation protected intact males from the impairing effects of letrozole, a non-impairing dose of flutamide was co-infused with letrozole. Co-administration of both drugs blocked object placement and object recognition memory consolidation, demonstrating that letrozole impairs memory in intact males only if androgen receptors are blocked. Together, these data suggest that DH-synthesized E2 and androgen receptor activation may work in concert to mediate memory consolidation in intact males, such that androgen receptor activation protects against memory impairments caused by aromatase inhibition.
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Affiliation(s)
- Wendy A Koss
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, United States of America.
| | - Karyn M Frick
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, United States of America.
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12
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Aromatase expression and function in the brain and behavior: A comparison across communication systems in teleosts. J Chem Neuroanat 2018; 94:139-153. [DOI: 10.1016/j.jchemneu.2018.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 09/09/2018] [Accepted: 10/14/2018] [Indexed: 11/18/2022]
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13
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Vahaba DM, Remage-Healey L. Neuroestrogens rapidly shape auditory circuits to support communication learning and perception: Evidence from songbirds. Horm Behav 2018; 104:77-87. [PMID: 29555375 PMCID: PMC7025793 DOI: 10.1016/j.yhbeh.2018.03.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/15/2018] [Accepted: 03/15/2018] [Indexed: 12/19/2022]
Abstract
Contribution to Special Issue on Fast effects of steroids. Steroid hormones, such as estrogens, were once thought to be exclusively synthesized in the ovaries and enact transcriptional changes over the course of hours to days. However, estrogens are also locally synthesized within neural circuits, wherein they rapidly (within minutes) modulate a range of behaviors, including spatial cognition and communication. Here, we review the role of brain-derived estrogens (neuroestrogens) as modulators within sensory circuits in songbirds. We first present songbirds as an attractive model to explore how neuroestrogens in auditory cortex modulate vocal communication processing and learning. Further, we examine how estrogens may enhance vocal learning and auditory memory consolidation in sensory cortex via mechanisms similar to those found in the hippocampus of rodents and birds. Finally, we propose future directions for investigation, including: 1) the extent of developmental and hemispheric shifts in aromatase and membrane estrogen receptor expression in auditory circuits; 2) how neuroestrogens may impact inhibitory interneurons to regulate audition and critical period plasticity; and, 3) dendritic spine plasticity as a candidate mechanism mediating estrogen-dependent effects on vocal learning. Together, this perspective of estrogens as neuromodulators in the vertebrate brain has opened new avenues in understanding sensory plasticity, including how hormones can act on communication circuits to influence behaviors in other vocal learning species, such as in language acquisition and speech processing in humans.
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Affiliation(s)
- Daniel M Vahaba
- Neuroscience and Behavior Program, Center for Neuroendocrine Studies, University of Massachusetts Amherst, Amherst, MA 01003, United States
| | - Luke Remage-Healey
- Neuroscience and Behavior Program, Center for Neuroendocrine Studies, University of Massachusetts Amherst, Amherst, MA 01003, United States.
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14
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Storman EM, Liu NJ, Wessendorf MW, Gintzler AR. Physical Linkage of Estrogen Receptor α and Aromatase in Rat: Oligocrine and Endocrine Actions of CNS-Produced Estrogens. Endocrinology 2018; 159:2683-2697. [PMID: 29771302 PMCID: PMC6692873 DOI: 10.1210/en.2018-00319] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 05/08/2018] [Indexed: 12/11/2022]
Abstract
Rapid-signaling membrane estrogen receptors (mERs) and aromatase (Aro) are present throughout the central nervous system (CNS), enabling acute regulation of CNS estrogenic signaling. We previously reported that spinal membrane Aro (mAro) and mERα oligomerize (1). As their organizational relationship would likely influence functions of locally produced estrogens, we quantified the mAro and mERα that are physically associated and nonassociated in two functionally different regions of rat CNS: the spinal cord, which has predominantly neural functionalities, and the hypothalamus, which has both neural and endocrine capabilities. Quantitative immunoprecipitation (IP), coimmunoprecipitation, and Western blot analysis were used to quantify the associated and nonassociated subpopulations of mAro and mERα. Regardless of estrous-cycle stage, virtually all mAro was oligomerized with mERα in the spinal cord, whereas only ∼15% was oligomerized in the hypothalamus. The predominance of nonassociated mAro in the hypothalamus, in combination with findings that many hypothalamic Aro-immunoreactive neurons could be retrogradely labeled with peripherally injected Fluoro-Gold, suggests that a portion of hypothalamic estrogens is secreted, potentially regulating pituitary function. Moreover, circulating estrogens increased hypothalamic Aro activity (quantified by the tritiated water-release assay) in the absence of increased Aro protein, revealing nongenomic regulation of Aro activity in the mammalian CNS. The demonstrated presence of associated and nonassociated mAro and mERα subpopulations in the CNS suggests that their selective targeting could restore impaired estrogen-dependent CNS functionalities while minimizing unwanted effects. The full physiological ramifications of brain-secreted estrogens remain to be explored.
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Affiliation(s)
- Emiliya M Storman
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, New York
| | - Nai-Jiang Liu
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, New York
| | - Martin W Wessendorf
- Department of Neuroscience, School of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Alan R Gintzler
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, New York
- Correspondence: Alan R. Gintzler, PhD, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York 11203. E-mail:
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15
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Neural-derived estradiol regulates brain plasticity. J Chem Neuroanat 2018; 89:53-59. [DOI: 10.1016/j.jchemneu.2017.04.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 03/16/2017] [Accepted: 04/12/2017] [Indexed: 01/12/2023]
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16
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Hojo Y, Kawato S. Neurosteroids in Adult Hippocampus of Male and Female Rodents: Biosynthesis and Actions of Sex Steroids. Front Endocrinol (Lausanne) 2018; 9:183. [PMID: 29740398 PMCID: PMC5925962 DOI: 10.3389/fendo.2018.00183] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 04/04/2018] [Indexed: 12/13/2022] Open
Abstract
The brain is not only the target of steroid hormones but also is able to locally synthesize steroids de novo. Evidence of the local production of steroids in the brain has been accumulating in various vertebrates, including teleost fish, amphibia, birds, rodents, non-human primates, and humans. In this review, we mainly focus on the local production of sex steroids in the hippocampal neurons of adult rodents (rats and mice), a center for learning and memory. From the data of the hippocampus of adult male rats, hippocampal principal neurons [pyramidal cells in CA1-CA3 and granule cells in dentate gyrus (DG)] have a complete system for biosynthesis of sex steroids. Liquid chromatography with tandem-mass-spectrometry (LC-MS/MS) enabled us to accurately determine the levels of hippocampal sex steroids including 17β-estradiol (17β-E2), testosterone (T), and dihydrotestosterone (DHT), which are much higher than those in blood. Next, we review the steroid synthesis in the hippocampus of female rats, since previous knowledge had been biased toward the data from males. Recently, we clarified that the levels of hippocampal steroids fluctuate in adult female rats across the estrous cycle. Accurate determination of hippocampal steroids at each stage of the estrous cycle is of importance for providing the account for the fluctuation of female hippocampal functions, including spine density, long-term potentiation (LTP) and long-term depression (LTD), and learning and memory. These functional fluctuations in female had been attributed to the level of circulation-derived steroids. LC-MS/MS analysis revealed that the dendritic spine density in CA1 of adult female hippocampus correlates with the levels of hippocampal progesterone and 17β-E2. Finally, we introduce the direct evidence of the role of hippocampus-synthesized steroids in hippocampal function including neurogenesis, LTP, and memory consolidation. Mild exercise (2 week of treadmill running) elevated synthesis of DHT in the hippocampus, but not in the testis, of male rats, resulting in enhancement of neurogenesis in DG. Concerning synaptic plasticity, hippocampus-synthesized E2 is required for LTP induction, whereas hippocampus-synthesized DHT is required for LTD induction. Furthermore, hippocampus-synthesized E2 is involved in memory consolidation tested by object recognition and object placement tasks, both of which are hippocampus-dependent.
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Affiliation(s)
- Yasushi Hojo
- Department of Biochemistry, Faculty of Medicine, Saitama Medical University, Moroyama, Saitama, Japan
- *Correspondence: Yasushi Hojo,
| | - Suguru Kawato
- Department of Biophysics and Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
- Department of Urology, Graduate School of Medicine, Juntendo University, Tokyo, Japan
- Department of Cognitive Neuroscience, Faculty of Pharma-Science, Teikyo University, Tokyo, Japan
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17
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Golden LC, Voskuhl R. The importance of studying sex differences in disease: The example of multiple sclerosis. J Neurosci Res 2017; 95:633-643. [PMID: 27870415 DOI: 10.1002/jnr.23955] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 08/19/2016] [Accepted: 09/06/2016] [Indexed: 12/20/2022]
Abstract
To date, scientific research has often focused on one sex, with assumptions that study of the other sex would yield similar results. However, many diseases affect males and females differently. The sex of a patient can affect the risk for both disease susceptibility and progression. Such differences can be brought to the laboratory bench to be investigated, potentially bringing new treatments back to the clinic. This method of research, known as a "bedside to bench to bedside" approach, has been applied to studying sex differences in multiple sclerosis (MS). Females have greater susceptibly to MS, while males have worse disease progression. These two characteristics of the disease are influenced by the immune system and the nervous system, respectively. Thus, sex differences in each system must be studied. Personalized medicine has been at the forefront of research recently, and studying sex differences in disease fits with this initiative. This review will discuss the known sex differences in MS and highlight how investigating them can lead to new insights and potential treatments for both men and women. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Lisa C Golden
- Department of Neurology, University of California Los Angeles, Los Angeles, California.,Molecular Biology IDP, University of California Los Angeles, Los Angeles, California
| | - Rhonda Voskuhl
- Department of Neurology, University of California Los Angeles, Los Angeles, California
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18
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Estradiol Modulates Hemispheric Lateralization of Auditory Evoked Neural Activity in Male European Starlings ( Sturnus vulgaris). J Neurosci 2017; 37:7800-7802. [PMID: 28821600 DOI: 10.1523/jneurosci.1414-17.2017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/11/2017] [Accepted: 07/15/2017] [Indexed: 11/21/2022] Open
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19
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Tran M, Kuhn JA, Bráz JM, Basbaum AI. Neuronal aromatase expression in pain processing regions of the medullary and spinal cord dorsal horn. J Comp Neurol 2017. [PMID: 28649695 DOI: 10.1002/cne.24269] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In both acute and chronic pain conditions, women tend to be more sensitive than men. This sex difference may be regulated by estrogens, such as estradiol, that are synthesized in the spinal cord and brainstem and act locally to influence pain processing. To identify a potential cellular source of local estrogen, here we examined the expression of aromatase, the enzyme that catalyzes the conversion of testosterone to estradiol. Our studies focused on primary afferent neurons and on their central targets in the spinal cord and medulla as well as in the nucleus of the solitary tract, the target of nodose ganglion-derived visceral afferents. Immunohistochemical staining in an aromatase reporter mouse revealed that many neurons in laminae I and V of the spinal cord dorsal horn and caudal spinal trigeminal nucleus and in the nucleus of the solitary tract express aromatase. The great majority of these cells also express inhibitory interneuron markers. We did not find sex differences in aromatase expression and neither the pattern nor the number of neurons changed in a sciatic nerve transection model of neuropathic pain or in the Complete Freund's adjuvant model of inflammatory pain. A few aromatase neurons express Fos after cheek injection of capsaicin, formalin, or chloroquine. In total, given their location, these aromatase neurons are poised to engage nociceptive circuits, whether it is through local estrogen synthesis or inhibitory neurotransmitter release.
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Affiliation(s)
- May Tran
- Department of Anatomy, University of California, San Francisco, San Francisco, California
| | - Julia A Kuhn
- Department of Anatomy, University of California, San Francisco, San Francisco, California
| | - João M Bráz
- Department of Anatomy, University of California, San Francisco, San Francisco, California
| | - Allan I Basbaum
- Department of Anatomy, University of California, San Francisco, San Francisco, California
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20
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Lara-García M, Alvarado M, Cuevas E, Lara-García O, Sengelaub DR, Pacheco P. Hormonal Treatment Effects on the Cross-sectional Area of Pubococcygeus Muscle Fibers After Denervation and Castration in Male Rats. Anat Rec (Hoboken) 2017; 300:1327-1335. [PMID: 28176462 DOI: 10.1002/ar.23565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 07/01/2016] [Accepted: 08/22/2016] [Indexed: 11/07/2022]
Abstract
We explore the interaction of muscle innervation and gonadal hormone action in the pubococcygeus muscle (Pcm) after castration and hormone replacement. Male Wistar rats were castrated and the Pcm was unilaterally denervated; after 2 or 6 weeks, the cross-sectional area (CSA) of Pcm fibers was assessed. Additional groups of castrated rats were used to examine the effects of hormone replacement. At 2 weeks post surgeries, rats were implanted with Silastic capsules containing either dihydrotestosterone (DHT), estradiol benzoate (EB) or both hormones, and the CSA of Pcm fibers was assessed after 4 weeks of hormone treatment. At 2 weeks post surgeries, gonadectomy without hormone replacement resulted in reductions in the CSA of Pcm fibers, and denervation combined with castration increased the magnitude of this effect; further reductions in CSA were present at 6 weeks post surgeries, but again denervation combined with castration increased the magnitude of this effect. Hormone replacement with DHT resulted in hypertrophy in the CSA of nondenervated muscles compared to those of intact normal males, but this effect was attenuated in denervated muscles. Hormone replacement with EB treatment prevented further castration-induced reductions in CSA of nondenervated muscles, but denervation prevented this effect. Similar to that seen with treatment with EB alone, combined treatment with both DHT and EB prevented further reductions in CSA of Pcm fibers in nondenervated muscles, but again denervation attenuated this effect. Thus, while hormone replacement can reverse or prevent further castration-induced atrophy of Pcm fibers, these effects are dependent on muscle innervation. Anat Rec, 300:1327-1335, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Miguel Lara-García
- Departamento de Neurofisiología, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz, México
- Departamento de Endocrinología, Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México
| | - Mayvi Alvarado
- Departamento de Neurofisiología, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz, México
| | - Estela Cuevas
- Departamento de Endocrinología, Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México
| | - Omar Lara-García
- Departamento de Neurofisiología, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz, México
| | - Dale R Sengelaub
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana
| | - Pablo Pacheco
- Departamento de Neurofisiología, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz, México
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, DF, México
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21
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Maysinger D, Ji J, Hutter E, Cooper E. Nanoparticle-Based and Bioengineered Probes and Sensors to Detect Physiological and Pathological Biomarkers in Neural Cells. Front Neurosci 2015; 9:480. [PMID: 26733793 PMCID: PMC4683200 DOI: 10.3389/fnins.2015.00480] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 11/30/2015] [Indexed: 01/11/2023] Open
Abstract
Nanotechnology, a rapidly evolving field, provides simple and practical tools to investigate the nervous system in health and disease. Among these tools are nanoparticle-based probes and sensors that detect biochemical and physiological properties of neurons and glia, and generate signals proportionate to physical, chemical, and/or electrical changes in these cells. In this context, quantum dots (QDs), carbon-based structures (C-dots, grapheme, and nanodiamonds) and gold nanoparticles are the most commonly used nanostructures. They can detect and measure enzymatic activities of proteases (metalloproteinases, caspases), ions, metabolites, and other biomolecules under physiological or pathological conditions in neural cells. Here, we provide some examples of nanoparticle-based and genetically engineered probes and sensors that are used to reveal changes in protease activities and calcium ion concentrations. Although significant progress in developing these tools has been made for probing neural cells, several challenges remain. We review many common hurdles in sensor development, while highlighting certain advances. In the end, we propose some future directions and ideas for developing practical tools for neural cell investigations, based on the maxim "Measure what is measurable, and make measurable what is not so" (Galileo Galilei).
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Affiliation(s)
- Dusica Maysinger
- Department of Pharmacology and Therapeutics, McGill University Montreal, QC, Canada
| | - Jeff Ji
- Department of Pharmacology and Therapeutics, McGill University Montreal, QC, Canada
| | - Eliza Hutter
- Department of Pharmacology and Therapeutics, McGill University Montreal, QC, Canada
| | - Elis Cooper
- Department of Physiology, McGill University Montreal, QC, Canada
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22
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Korol DL, Pisani SL. Estrogens and cognition: Friends or foes?: An evaluation of the opposing effects of estrogens on learning and memory. Horm Behav 2015; 74:105-15. [PMID: 26149525 PMCID: PMC4573330 DOI: 10.1016/j.yhbeh.2015.06.017] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 06/19/2015] [Accepted: 06/25/2015] [Indexed: 12/19/2022]
Abstract
This article is part of a Special Issue "Estradiol and cognition". Estrogens are becoming well known for their robust enhancement on cognition particularly for learning and memory that relies upon functioning of the hippocampus and related neural systems. What is also emerging is that estrogen modulation of cognition is not uniform, at times enhancing yet at other times impairing learning. This review explores the bidirectional effects of estrogens on learning from a multiple memory systems view, focusing on the hippocampus and striatum, whereby modulation by estrogens sorts according to task attributes and neural systems engaged during cognition. We highlight our findings showing that the ability to solve hippocampus-sensitive tasks typically improves under relatively high estrogen status while the ability to solve striatum-sensitive tasks degrades with estrogen exposures. Though constrained by dose and timing of exposure, these opposing enhancements and impairments of cognition can be observed following treatments with different estrogenic compounds including the hormone estradiol, the isoflavone genistein found in soybeans, and agonists that are selective for specific estrogen receptors, suggesting that activation of a single receptor type is sufficient to produce the observed shifts in learning strategies. Using this multi-dimensional framework will allow us to extend our thinking of the relationship between estrogens and cognition to other brain regions and cognitive functions.
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Affiliation(s)
- Donna L Korol
- Department of Biology, Syracuse University, Department of Neuroscience and Physiology, SUNY-Upstate Medical University, Syracuse, NY 13244, USA.
| | - Samantha L Pisani
- Neuroscience Program and Medical Scholars Program, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
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23
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Bailey DJ, Saldanha CJ. The importance of neural aromatization in the acquisition, recall, and integration of song and spatial memories in passerines. Horm Behav 2015; 74:116-24. [PMID: 26122300 PMCID: PMC9366902 DOI: 10.1016/j.yhbeh.2015.06.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 01/13/2023]
Abstract
This article is part of a Special Issue "Estradiol and cognition". In addition to their well-studied and crucial effects on brain development and aging, an increasing number of investigations across vertebrate species indicate that estrogens like 17β-estradiol (E2) have pronounced and rapid effects on cognitive function. The incidence and regulation of the E2-synthesizing enzyme aromatase at the synapse in regions of the brain responsible for learning, memory, social communication and other complex cognitive processes suggest that local E2 production and action affect the acute and chronic activity of individual neurons and circuits. Songbirds in particular are excellent models for the study of this "synaptocrine" hormone provision given that aromatase is abundantly expressed in neuronal soma, dendrites, and at the synapse across many brain regions in both sexes. Additionally, songbirds readily acquire and recall memories in laboratory settings, and their stereotyped behaviors may be manipulated and measured with relative ease. This leads to a rather unparalleled advantage in the use of these animals in studies of the role of neural aromatization in cognition. In this review we describe the results of a number of experiments in songbird species with a focus on the influence of synaptic E2 provision on two cognitive processes: auditory discrimination reliant on the caudomedial nidopallium (NCM), a telencephalic region likely homologous to the auditory cortex in mammals, and spatial memory dependent on the hippocampus. Data from these studies are providing evidence that the local and acute provision of E2 modulates the hormonal, electrical, and cognitive outputs of the vertebrate brain and aids in memory acquisition, retention, and perhaps the confluence of memory systems.
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Affiliation(s)
- David J Bailey
- Biology, St. Norbert College, De Pere, WI 54115, United States.
| | - Colin J Saldanha
- Department of Biology, American University, Washington, DC 20016, United States; Department of Psychology, American University, Washington, DC 20016, United States.
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24
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Maruska KP. Social Transitions Cause Rapid Behavioral and Neuroendocrine Changes. Integr Comp Biol 2015; 55:294-306. [PMID: 26037297 DOI: 10.1093/icb/icv057] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
In species that form dominance hierarchies, there are often opportunities for low-ranking individuals to challenge high-ranking ones, resulting in a rise or fall in social rank. How does an animal rapidly detect, process, and then respond to these social transitions? This article explores and summarizes how these social transitions can rapidly (within 24 h) impact an individual's behavior, physiology, and brain, using the African cichlid fish, Astatotilapia burtoni, as a model. Male A. burtoni form hierarchies in which a few brightly-colored dominant males defend territories and spawn with females, while the remaining males are subordinate, more drab-colored, do not hold a territory, and have minimal opportunities for reproduction. These social phenotypes are plastic and reversible, meaning that individual males may switch between dominant and subordinate status multiple times within a lifetime. When the social environment is manipulated to create males that either ascend (subordinate to dominant) or descend (dominant to subordinate) in rank, there are rapid changes in behavior, circulating hormones, and levels of gene expression in the brain that reflect the direction of transition. For example, within minutes, males ascending in status show bright coloration, a distinct eye-bar, increased dominance behaviors, activation of brain nuclei in the social behavior network, and higher levels of sex steroids in the plasma. Ascending males also show rapid changes in levels of neuropeptide and steroid receptors in the brain, as well as in the pituitary and testes. To further examine hormone-behavior relationships in this species during rapid social ascent, the present study also measured levels of testosterone, 11-ketotestosterone, estradiol, progestins, and cortisol in the plasma during the first week of social ascent and tested for correlations with behavior. Plasma levels of all steroids were rapidly increased at 30 min after social ascent, but were not correlated with behavior during the initial rise in rank, suggesting that behavior is dissociated from endocrine status. These changes during social ascent are then compared with our current knowledge about males descending in rank, who rapidly show faded coloration, decreased dominance behaviors, increased subordinate behaviors, and higher circulating levels of cortisol. Collectively, this work highlights how the perception of similar social cues that are opposite in value are rapidly translated into adaptive behavioral and neuroendocrine changes that promote survival and reproductive fitness. Finally, future directions are proposed to better understand the mechanisms that govern these rapid changes in social position.
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Affiliation(s)
- Karen P Maruska
- Department of Biological Sciences, Louisiana State University, 202 Life Sciences Bldg, Baton Rouge, LA 70803, USA
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25
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Calisi RM, Saldanha CJ. Neurohormones, Brain, and Behavior: A Comparative Approach to Understanding Rapid Neuroendocrine Action. Integr Comp Biol 2015; 55:264-7. [PMID: 25896107 DOI: 10.1093/icb/icv007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The definition of a hormone has been in part delineated by its journey to distant receptor targets. Following activation of a receptor, a subsequent reaction facilitates the regulation of physiology and, ultimately, behavior. However, a growing number of studies report that hormones can influence these events at a previously underappreciated high speed. With the potential to act as neurotransmitters, the definition of a hormone and its mechanisms of action are evolving. In this symposium, we united scientists who use contemporary molecular, electrophysiological, and biochemical approaches to study aspects of rapid hormone action in a broad array of systems across different levels of biological organization. What emerged was an overwhelming consensus that the use of integrative and comparative approaches fuels discovery and increases our understanding of de novo hormone synthesis, local actions of neurohormones, and subsequent effects on neuroplasticity and behavior.
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Affiliation(s)
- Rebecca M Calisi
- *Department of Biology, Barnard College, Columbia University, New York, NY 10027, USA;
| | - Colin J Saldanha
- Department of Biology, American University, Washington, D.C. 20016, USA
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26
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Rainville J, Pollard K, Vasudevan N. Membrane-initiated non-genomic signaling by estrogens in the hypothalamus: cross-talk with glucocorticoids with implications for behavior. Front Endocrinol (Lausanne) 2015; 6:18. [PMID: 25762980 PMCID: PMC4329805 DOI: 10.3389/fendo.2015.00018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Accepted: 01/30/2015] [Indexed: 12/12/2022] Open
Abstract
The estrogen receptor and glucocorticoid receptor are members of the nuclear receptor superfamily that can signal using both non-genomic and genomic transcriptional modes. Though genomic modes of signaling have been well characterized and several behaviors attributed to this signaling mechanism, the physiological significance of non-genomic modes of signaling has not been well understood. This has partly been due to the controversy regarding the identity of the membrane ER (mER) or membrane GR (mGR) that may mediate rapid, non-genomic signaling and the downstream signaling cascades that may result as a consequence of steroid ligands binding the mER or the mGR. Both estrogens and glucocorticoids exert a number of actions on the hypothalamus, including feedback. This review focuses on the various candidates for the mER or mGR in the hypothalamus and the contribution of non-genomic signaling to classical hypothalamically driven behaviors and changes in neuronal morphology. It also attempts to categorize some of the possible functions of non-genomic signaling at both the cellular level and at the organismal level that are relevant for behavior, including some behaviors that are regulated by both estrogens and glucocorticoids in a potentially synergistic manner. Lastly, it attempts to show that steroid signaling via non-genomic modes may provide the organism with rapid behavioral responses to stimuli.
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Affiliation(s)
- Jennifer Rainville
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, USA
| | - Kevin Pollard
- Neuroscience Program, Tulane University, New Orleans, LA, USA
| | - Nandini Vasudevan
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, USA
- Neuroscience Program, Tulane University, New Orleans, LA, USA
- *Correspondence: Nandini Vasudevan, Department of Cell and Molecular Biology, Tulane University, 2000 Percival Stern Hall, New Orleans, LA 70118, USA e-mail:
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27
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Arevalo MA, Azcoitia I, Garcia-Segura LM. The neuroprotective actions of oestradiol and oestrogen receptors. Nat Rev Neurosci 2014; 16:17-29. [PMID: 25423896 DOI: 10.1038/nrn3856] [Citation(s) in RCA: 305] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hormones regulate homeostasis by communicating through the bloodstream to the body's organs, including the brain. As homeostatic regulators of brain function, some hormones exert neuroprotective actions. This is the case for the ovarian hormone 17β-oestradiol, which signals through oestrogen receptors (ERs) that are widely distributed in the male and female brain. Recent discoveries have shown that oestradiol is not only a reproductive hormone but also a brain-derived neuroprotective factor in males and females and that ERs coordinate multiple signalling mechanisms that protect the brain from neurodegenerative diseases, affective disorders and cognitive decline.
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Affiliation(s)
- Maria-Angeles Arevalo
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain
| | - Iñigo Azcoitia
- Department of Cell Biology, Faculty of Biology, Universidad Complutense, E-28040 Madrid, Spain
| | - Luis M Garcia-Segura
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain
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28
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Remage-Healey L. Frank Beach Award Winner: Steroids as neuromodulators of brain circuits and behavior. Horm Behav 2014; 66:552-60. [PMID: 25110187 PMCID: PMC4180446 DOI: 10.1016/j.yhbeh.2014.07.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/30/2014] [Accepted: 07/31/2014] [Indexed: 11/27/2022]
Abstract
Neurons communicate primarily via action potentials that transmit information on the timescale of milliseconds. Neurons also integrate information via alterations in gene transcription and protein translation that are sustained for hours to days after initiation. Positioned between these two signaling timescales are the minute-by-minute actions of neuromodulators. Over the course of minutes, the classical neuromodulators (such as serotonin, dopamine, octopamine, and norepinephrine) can alter and/or stabilize neural circuit patterning as well as behavioral states. Neuromodulators allow many flexible outputs from neural circuits and can encode information content into the firing state of neural networks. The idea that steroid molecules can operate as genuine behavioral neuromodulators - synthesized by and acting within brain circuits on a minute-by-minute timescale - has gained traction in recent years. Evidence for brain steroid synthesis at synaptic terminals has converged with evidence for the rapid actions of brain-derived steroids on neural circuits and behavior. The general principle emerging from this work is that the production of steroid hormones within brain circuits can alter their functional connectivity and shift sensory representations by enhancing their information coding. Steroids produced in the brain can therefore change the information content of neuronal networks to rapidly modulate sensory experience and sensorimotor functions.
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Affiliation(s)
- Luke Remage-Healey
- Neuroscience and Behavior Program, Center for Neuroendocrine Studies, Department of Psychological and Brain Sciences, University of Massachusetts Amherst, 01003, USA.
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29
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Aromatase, estrogen receptors and brain development in fish and amphibians. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:152-62. [PMID: 25038582 DOI: 10.1016/j.bbagrm.2014.07.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 06/19/2014] [Accepted: 07/07/2014] [Indexed: 12/20/2022]
Abstract
Estrogens affect brain development of vertebrates, not only by impacting activity and morphology of existing circuits, but also by modulating embryonic and adult neurogenesis. The issue is complex as estrogens can not only originate from peripheral tissues, but also be locally produced within the brain itself due to local aromatization of androgens. In this respect, teleost fishes are quite unique because aromatase is expressed exclusively in radial glial cells, which represent pluripotent cells in the brain of all vertebrates. Expression of aromatase in the brain of fish is also strongly stimulated by estrogens and some androgens. This creates a very intriguing positive auto-regulatory loop leading to dramatic aromatase expression in sexually mature fish with elevated levels of circulating steroids. Looking at the effects of estrogens or anti-estrogens in the brain of adult zebrafish showed that estrogens inhibit rather than stimulate cell proliferation and newborn cell migration. The functional meaning of these observations is still unclear, but these data suggest that the brain of fish is experiencing constant remodeling under the influence of circulating steroids and brain-derived neurosteroids, possibly permitting a diversification of sexual strategies, notably hermaphroditism. Recent data in frogs indicate that aromatase expression is limited to neurons and do not concern radial glial cells. Thus, until now, there is no other example of vertebrates in which radial progenitors express aromatase. This raises the question of when and why these new features were gained and what are their adaptive benefits. This article is part of a Special Issue entitled: Nuclear receptors in animal development.
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Schneider JE, Brozek JM, Keen-Rhinehart E. Our stolen figures: the interface of sexual differentiation, endocrine disruptors, maternal programming, and energy balance. Horm Behav 2014; 66:104-19. [PMID: 24681201 DOI: 10.1016/j.yhbeh.2014.03.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 03/15/2014] [Accepted: 03/18/2014] [Indexed: 02/06/2023]
Abstract
This article is part of a Special Issue "Energy Balance". The prevalence of adult obesity has risen markedly in the last quarter of the 20th century and has not been reversed in this century. Less well known is the fact that obesity prevalence has risen in domestic, laboratory, and feral animals, suggesting that all of these species have been exposed to obesogenic factors present in the environment. This review emphasizes interactions among three biological processes known to influence energy balance: Sexual differentiation, endocrine disruption, and maternal programming. Sexual dimorphisms include differences between males and females in body weight, adiposity, adipose tissue distribution, ingestive behavior, and the underlying neural circuits. These sexual dimorphisms are controlled by sex chromosomes, hormones that masculinize or feminize adult body weight during perinatal development, and hormones that act during later periods of development, such as puberty. Endocrine disruptors are natural and synthetic molecules that attenuate or block normal hormonal action during these same developmental periods. A growing body of research documents effects of endocrine disruptors on the differentiation of adipocytes and the central nervous system circuits that control food intake, energy expenditure, and adipose tissue storage. In parallel, interest has grown in epigenetic influences, including maternal programming, the process by which the mother's experience has permanent effects on energy-balancing traits in the offspring. This review highlights the points at which maternal programming, sexual differentiation, and endocrine disruption might dovetail to influence global changes in energy balancing traits.
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Affiliation(s)
- Jill E Schneider
- Lehigh University, Department of Biological Sciences, Bethlehem, PA 18015, USA.
| | - Jeremy M Brozek
- Lehigh University, Department of Biological Sciences, Bethlehem, PA 18015, USA
| | - Erin Keen-Rhinehart
- Susquehanna University, Department of Biological Sciences, Selinsgrove, PA 17870, USA
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Rilling JK, DeMarco AC, Hackett PD, Chen X, Gautam P, Stair S, Haroon E, Thompson R, Ditzen B, Patel R, Pagnoni G. Sex differences in the neural and behavioral response to intranasal oxytocin and vasopressin during human social interaction. Psychoneuroendocrinology 2014; 39:237-248. [PMID: 24157401 PMCID: PMC3842401 DOI: 10.1016/j.psyneuen.2013.09.022] [Citation(s) in RCA: 241] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 09/03/2013] [Accepted: 09/19/2013] [Indexed: 11/28/2022]
Abstract
Both oxytocin (OT) and vasopressin (AVP) are known to modulate social behavior, and dysfunction in both systems has been postulated as a potential cause of certain psychiatric disorders that involve social behavioral deficits. In particular, there is growing interest in intranasal OT as a potential treatment for certain psychiatric disorders, and preliminary pre-clinical and clinical studies suggest efficacy in alleviating some of the associated symptoms. However, the vast majority of research participants in these studies have been male, and there is evidence for sexually differentiated effects of nonapeptides in both humans and non-human animals. To date, no study has investigated the effect of intranasal OT on brain function in human males and females within the same paradigm. Previously, in a randomized, placebo-controlled, double-blind fMRI study, we reported effects of intranasal OT and AVP on behavior and brain activity of human males as they played an interactive social game known as the Prisoner's Dilemma Game. Here, we present findings from an identical study in human females, and compare these with our findings from males. Overall, we find that both behavioral and neural responses to intranasal OT and AVP are highly sexually differentiated. In women, AVP increased conciliatory behavior, and both OT and AVP caused women to treat computer partners more like humans. In men, AVP increased reciprocation of cooperation from both human and computer partners. However, no specific drug effects on behavior were shared between men and women. During cooperative interactions, both OT and AVP increased brain activity in men within areas rich in OT and AVP receptors and in areas playing a key role in reward, social bonding, arousal and memory (e.g., the striatum, basal forebrain, insula, amygdala and hippocampus), whereas OT and AVP either had no effect or in some cases actually decreased brain activity in these regions in women. OT treatment rendered neural responses of males more similar to responses of females in the placebo group and vice versa, raising the prospect of an inverted u-shaped dose response to central OT levels. These findings emphasize the need to fully characterize the effects of intranasal OT and AVP in both males and females and at multiple doses before widespread clinical application will be warranted.
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Affiliation(s)
- James K Rilling
- Department of Anthropology, Emory University, United States; Department of Psychiatry and Behavioral Sciences, Emory University, United States; Center for Behavioral Neuroscience, Emory University, United States; Yerkes National Primate Research Center, Emory University, United States; Center for Translational Social Neuroscience, Emory University, United States.
| | | | | | - Xu Chen
- Department of Anthropology, Emory University, United States; Department of Psychiatry and Behavioral Sciences, Emory University, United States
| | - Pritam Gautam
- Department of Anthropology, Emory University, United States
| | - Sabrina Stair
- Department of Psychiatry and Behavioral Sciences, Emory University, United States
| | - Ebrahim Haroon
- Department of Psychiatry and Behavioral Sciences, Emory University, United States
| | | | - Beate Ditzen
- Department of Psychiatry and Behavioral Sciences, Emory University, United States; Center for Behavioral Neuroscience, Emory University, United States; Department of Psychology, University of Zurich, Switzerland
| | - Rajan Patel
- Department of Biostatistics, Emory University, United States
| | - Giuseppe Pagnoni
- Department of Neural, Biomedical, and Metabolic Sciences, University of Modena and Reggio Emilia, Italy
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Remage-Healey L, Jeon SD, Joshi NR. Recent evidence for rapid synthesis and action of oestrogens during auditory processing in a songbird. J Neuroendocrinol 2013; 25:1024-31. [PMID: 23746380 PMCID: PMC4153829 DOI: 10.1111/jne.12055] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 05/13/2013] [Accepted: 06/01/2013] [Indexed: 11/28/2022]
Abstract
It is now clear that oestrogens are not only circulating reproductive hormones, but that they also have neurotransmitter-like properties in a wide range of brain circuits. The view of oestrogens as intrinsic neuromodulators that shape behaviour has been bolstered by a series of recent developments from multiple vertebrate model systems. Here, we review several recent findings from studies of songbirds showing how the identified neural circuits that govern auditory processing and sensorimotor integration are modulated by the local and acute production of oestrogens. First, studies using in vivo microdialysis demonstrate that oestrogens fluctuate in the auditory cortex (30-min time bin resolution) when songbirds are hearing song and interacting with conspecifics. Second, oestrogens rapidly boost the auditory-evoked activity of neurones in the same auditory cortical region, enhancing auditory processing. Third, local pharmacological blockade of oestrogen signalling in this region impairs auditory neuronal responsiveness, as well as behavioural song preferences. Fourth, the rapid actions of oestrogens that occur within the auditory cortex can propagate downstream (trans-synaptically) to sensorimotor circuits to enhance the neural representation of song. Lastly, we present new evidence showing that the receptor for the rapid actions of oestradiol is likely in neuronal membranes, and that traditional nuclear oestrogen receptor agonists do not mimic these rapid actions. Broadly speaking, many of these findings are observed in both males and females, emphasising the fundamental importance of oestrogens in neural circuit function. Together, these and other emergent studies provide support for rapid, brain-derived oestrogen signalling in regulating sensorimotor integration, learning and perception.
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Remage-Healey L. Brain estrogen signaling effects acute modulation of acoustic communication behaviors: A working hypothesis. Bioessays 2012; 34:1009-16. [PMID: 23065844 DOI: 10.1002/bies.201200081] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Although estrogens are widely considered circulating "sex steroid hormones" typically associated with female reproduction, recent evidence suggests that estrogens can act as local modulators of brain circuits in both males and females. The functional implications of this newly characterized estrogen signaling system have begun to emerge. This essay summarizes evidence in support of the hypothesis that the rapid production of estrogens in brain circuits can drive acute changes in both the production and perception of acoustic communication behaviors. These studies have revealed two fundamental neurobiological concepts: (1) estrogens can be locally produced in brain circuits, independent of levels in nearby circuits and in the circulation and (2) estrogens can have very rapid effects within these brain circuits to modulate social vocalizations, acoustic processing, and sensorimotor integration. This vertebrate-wide span of research, including vocalizing fishes, amphibians, and birds, emphasizes the importance of comparative model systems in understanding principles of neurobiology.
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Affiliation(s)
- Luke Remage-Healey
- Neuroscience and Behavior Program, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, MA, USA.
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Remage-Healey L, Dong SM, Chao A, Schlinger BA. Sex-specific, rapid neuroestrogen fluctuations and neurophysiological actions in the songbird auditory forebrain. J Neurophysiol 2011; 107:1621-31. [PMID: 22190616 DOI: 10.1152/jn.00749.2011] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Recent evidence shows that brain-derived steroids such as estrogens ("neuroestrogens") are controlled in a manner very similar to traditional neurotransmitters. The advent of in vivo microdialysis for steroids in songbirds has provided new information about the spatial and temporal dynamics of neuroestrogen changes in a region of the auditory cortex, the caudomedial nidopallium (NCM). Here, experiments using in vivo microdialysis demonstrate that neuroestradiol (E(2)) fluctuations occur within the auditory NCM during presentation of naturalistic auditory and visual stimuli in males but only to the presentation of auditory stimuli in females. These changes are acute (within 30 min) and appear to be specific to the NCM, because similar treatments elicit no changes in E(2) in a nearby mesopallial region or in circulating plasma. Further experiments coupling in vivo steroid microdialysis with extracellular recordings in NCM show that neuroestrogens rapidly boost auditory responses to song stimuli in females, similar to recent observations in males. We also find that the rapid actions of estradiol on auditory responses are fully mimicked by the cell membrane-impermeable estrogen biotinylestradiol, consistent with acute estrogen actions at the neuronal membrane. Thus we conclude that local and acute E(2) flux is regulated by convergent multimodal sensory input, and that this regulation appears to be sex-specific. Second, rapid changes in local E(2) levels in NCM have consequences for the modulation of auditory processing in females and males. Finally, the rapid actions of neuroestrogens on NCM auditory processing appear to be mediated by a nonclassical, membrane-bound estrogen receptor.
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Affiliation(s)
- L Remage-Healey
- Neuroscience and Behavior Program, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003, USA.
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