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Kritzer MF, Adler A, Locklear M. Androgen effects on mesoprefrontal dopamine systems in the adult male brain. Neuroscience 2024:S0306-4522(24)00306-3. [PMID: 38977069 DOI: 10.1016/j.neuroscience.2024.07.001] [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: 04/22/2024] [Revised: 06/25/2024] [Accepted: 07/02/2024] [Indexed: 07/10/2024]
Abstract
Epidemiological data show that males are more often and/or more severely affected by symptoms of prefrontal cortical dysfunction in schizophrenia, Parkinson's disease and other disorders in which dopamine circuits associated with the prefrontal cortex are dysregulated. This review focuses on research showing that these dopamine circuits are powerfully regulated by androgens. It begins with a brief overview of the sex differences that distinguish prefrontal function in health and prefrontal dysfunction or decline in aging and/or neuropsychiatric disease. This review article then spotlights data from human subjects and animal models that specifically identify androgens as potent modulators of prefrontal cortical operations and of closely related, functionally critical measures of prefrontal dopamine level or tone. Candidate mechanisms by which androgens dynamically control mesoprefrontal dopamine systems and impact prefrontal states of hypo- and hyper-dopaminergia in aging and disease are then considered. This is followed by discussion of a working model that identifies a key locus for androgen modulation of mesoprefrontal dopamine systems as residing within the prefrontal cortex itself. The last sections of this review critically consider the ways in which the organization and regulation of mesoprefrontal dopamine circuits differ in the adult male and female brain, and highlights gaps where more research is needed.
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Affiliation(s)
- Mary F Kritzer
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230, United States.
| | - Alexander Adler
- Department of Oncology and Immuno-Oncology, Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, United States
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2
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Zhang Y, Chen M, Chen H, Mi S, Wang C, Zuo H, Song L, Du J, Cui H, Li S. Testosterone reduces hippocampal synaptic damage in an androgen receptor-independent manner. J Endocrinol 2024; 260:e230114. [PMID: 37991884 PMCID: PMC10762536 DOI: 10.1530/joe-23-0114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Accepted: 11/22/2023] [Indexed: 11/24/2023]
Abstract
Aging-related reduction in androgen levels may be a possible risk factor for neurodegenerative diseases and contribute to cognitive impairment. Androgens may affect synaptic function and cognition in an androgen receptor (AR)-independent manner; however, the mechanisms connecting theses effects are unknown. Therefore, we used testicular feminization mutation (Tfm) male mice, a model with AR mutation, to test the effects of testosterone on synaptic function and cognition. Our results showed that testosterone ameliorated spatial memory deficit and neuronal damage, and increased dendritic spines density and postsynaptic density protein 95 (PSD95) and glutamate receptor 1 (GluA1) expression in the hippocampus of Tfm male mice. And these effects of testosterone were not inhibited by anastrozole, which suppressed conversion of testosterone to estradiol. Mechanistically, testosterone activated the extracellular signal-related kinase 1/2 (Erk1/2) and cyclic adenosine monophosphate response element-binding protein (CREB) in the hippocampus of Tfm male mice. Meanwhile, Erk1/2 inhibitor SCH772984 blocked the upregulation of phospho-CREB, PSD95, and GluA1 induced by testosterone in HT22 cells pretreated with flutamide, an androgen antagonist. Collectively, our data indicate that testosterone may ameliorate hippocampal synaptic damage and spatial memory deficit by activating the Erk1/2-CREB signaling pathway in an AR-independent manner.
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Affiliation(s)
- Yizhou Zhang
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Meiqin Chen
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Huan Chen
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Shixiong Mi
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Chang Wang
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Hongchun Zuo
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Leigang Song
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Juan Du
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Huixian Cui
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Sha Li
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, Hebei, China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Hebei Medical University, Shijiazhuang, Hebei, China
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Gaynor AM, Flaherty KR, Root JC, Salas-Ramirez KY, Scott JM, Nelson CJ. Exercise Associated with Cognitive Function in Older Men with Prostate Cancer Undergoing Androgen Deprivation Therapy. Int J Behav Med 2023; 30:924-929. [PMID: 36717389 PMCID: PMC11326669 DOI: 10.1007/s12529-022-10150-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2022] [Indexed: 02/01/2023]
Abstract
BACKGROUND To examine associations between exercise and cognitive function in older men undergoing hormone therapy for prostate cancer. METHOD Men ≥ 65 years old with prostate cancer, currently undergoing androgen deprivation therapy for ≥ 6 months (n = 50), completed the Godin-Shephard Leisure-Time Physical Activity Questionnaire, and standard neuropsychological tests. Pearson's correlations and linear regressions were used to examine associations between exercise and cognitive performance. RESULTS Exercise was significantly positively correlated with performance on tests of memory, attention, and executive function. Linear regressions showed that when controlling for age and education, exercise remained a significant predictor of attention and executive function performance (p < 0.05), and showed moderate, but statistically non-significant effects on memory performance (p < 0.10). CONCLUSION Greater exercise is associated with better functioning in multiple cognitive domains in men with prostate cancer undergoing hormone therapy, providing proof-of-concept evidence that exercise may be a feasible intervention to limit cognitive dysfunction in prostate cancer patients.
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Affiliation(s)
- Alexandra M Gaynor
- Department of Psychiatry and Behavioral Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Taub Institute for Research On Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, USA.
| | - Kathleen R Flaherty
- Department of Psychiatry and Behavioral Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - James C Root
- Department of Psychiatry and Behavioral Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | | | - Jessica M Scott
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Christian J Nelson
- Department of Psychiatry and Behavioral Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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Boukari O, Khemissi W, Ghodhbane S, Lahbib A, Tebourbi O, Rhouma KB, Sakly M, Hallegue D. Effects of testosterone replacement on lipid profile, hepatotoxicity, oxidative stress, and cognitive performance in castrated wistar rats. Arch Ital Urol Androl 2023; 95:11593. [PMID: 38193231 DOI: 10.4081/aiua.2023.11593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 07/30/2023] [Indexed: 01/10/2024] Open
Abstract
OBJECTIVE Androgen deficiency is associated with multiple biochemical and behavioral disorders. This study investigated the effects of testosterone replacement and Spirulina Platensis association on testosterone deficiency-induced metabolic disorders and memory impairment. METHODS Adult male rats were randomly and equally divided into four groups and received the following treatments for 20 consecutive days. CONTROL GROUP non-castrated rats received distilled water. Castrated group received distilled water. Testosterone treated group: castrated rats received 0.20 mg of testosterone dissolved in corn oil by subcutaneous injection (i.p.). Spirulina co-treated group: castrated rats received 0.20 mg of testosterone (i.p.) dissolved in corn oil followed by 1000 mg/kg of Spirulina per os. RESULTS Data showed that castration induced an increase in plasma ALT, AST, alkaline phosphatase (PAL), cholesterol, and triglycerides level. Castrated rats showed a great elevation in SOD and CAT activities and MDA and H2O2 levels in the prostate, seminal vesicles, and brain. Testosterone deficiency was also associated with alteration of the spatial memory and exploratory behaviour. Testosterone replacement either alone or with Spirulina combination efficiently improved most of these biochemical parameters and ameliorated cognitive abilities in castrated rats. CONCLUSIONS Testosterone replacement either alone or in combination with Spirulina improved castration-induced metabolic, oxidative, and cognitive alterations.
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Affiliation(s)
- Oumayma Boukari
- Laboratory of Integrated Physiology, Department Life Sciences, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna 7021, Bizerte.
| | - Wahid Khemissi
- Laboratory of Integrated Physiology, Department Life Sciences, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna 7021, Bizerte.
| | - Soumaya Ghodhbane
- Laboratory of Integrated Physiology, Department Life Sciences, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna 7021, Bizerte.
| | - Aida Lahbib
- Laboratory of Integrated Physiology, Department Life Sciences, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna 7021, Bizerte.
| | - Olfa Tebourbi
- Laboratory of Integrated Physiology, Department Life Sciences, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna 7021, Bizerte.
| | - Khemais Ben Rhouma
- Laboratory of Integrated Physiology, Department Life Sciences, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna 7021, Bizerte.
| | - Mohsen Sakly
- Laboratory of Integrated Physiology, Department Life Sciences, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna 7021, Bizerte.
| | - Dorsaf Hallegue
- Laboratory of Integrated Physiology, Department Life Sciences, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna 7021, Bizerte.
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Shirokova O, Zaborskaya O, Pchelin P, Kozliaeva E, Pershin V, Mukhina I. Genetic and Epigenetic Sexual Dimorphism of Brain Cells during Aging. Brain Sci 2023; 13:brainsci13020195. [PMID: 36831738 PMCID: PMC9954625 DOI: 10.3390/brainsci13020195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 01/27/2023] Open
Abstract
In recent years, much of the attention paid to theoretical and applied biomedicine, as well as neurobiology, has been drawn to various aspects of sexual dimorphism due to the differences that male and female brain cells demonstrate during aging: (a) a dimorphic pattern of response to therapy for neurodegenerative disorders, (b) different age of onset and different degrees of the prevalence of such disorders, and (c) differences in their symptomatic manifestations in men and women. The purpose of this review is to outline the genetic and epigenetic differences in brain cells during aging in males and females. As a result, we hereby show that the presence of brain aging patterns in males and females is due to a complex of factors associated with the effects of sex chromosomes, which subsequently entails a change in signal cascades in somatic cells.
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Affiliation(s)
- Olesya Shirokova
- Institute of Fundamental Medicine, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Square, Nizhny Novgorod 603950, Russia
- Correspondence:
| | - Olga Zaborskaya
- Institute of Fundamental Medicine, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Square, Nizhny Novgorod 603950, Russia
| | - Pavel Pchelin
- Institute of Fundamental Medicine, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Square, Nizhny Novgorod 603950, Russia
- Institute of Biology and Biomedicine, Lobachevsky State University, 23 Gagarin Avenue, Nizhny Novgorod 603002, Russia
| | - Elizaveta Kozliaeva
- Institute of Fundamental Medicine, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Square, Nizhny Novgorod 603950, Russia
| | - Vladimir Pershin
- Institute of Fundamental Medicine, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Square, Nizhny Novgorod 603950, Russia
- Institute of Biology and Biomedicine, Lobachevsky State University, 23 Gagarin Avenue, Nizhny Novgorod 603002, Russia
| | - Irina Mukhina
- Institute of Fundamental Medicine, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Square, Nizhny Novgorod 603950, Russia
- Institute of Biology and Biomedicine, Lobachevsky State University, 23 Gagarin Avenue, Nizhny Novgorod 603002, Russia
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Evaluation of the effect of nicotine and O-acetyl-L-carnitine on testosterone-induced spatial learning impairment in Morris water maze and assessment of protein markers. LEARNING AND MOTIVATION 2022. [DOI: 10.1016/j.lmot.2022.101810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Bianchi VE. Impact of Testosterone on Alzheimer's Disease. World J Mens Health 2022; 40:243-256. [PMID: 35021306 PMCID: PMC8987133 DOI: 10.5534/wjmh.210175] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/16/2021] [Accepted: 09/23/2021] [Indexed: 11/15/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease responsible for almost half of all dementia cases in the world and progressively increasing. The etiopathology includes heritability, genetic factors, aging, nutrition, but sex hormones play a relevant role. Animal models demonstrated that testosterone (T) exerted a neuroprotective effect reducing the production of amyloid-beta (Aβ), improving synaptic signaling, and counteracting neuronal death. This study aims to evaluate the impact of T deprivation and T administration in humans on the onset of dementia and AD. A search was conducted on MEDLINE and Scopus for the “androgen deprivation therapy” and “testosterone therapy” with “dementia” and “Alzheimer’s.” Studies lasting twenty years with low risk of bias, randomized clinical trial, and case-controlled studies were considered. Twelve articles on the effect of androgen deprivation therapy (ADT) and AD and seventeen on T therapy and AD were retrieved. Men with prostate cancer under ADT showed a higher incidence of dementia and AD. The effect of T administration in hypogonadal men with AD and cognitive impairment has evidenced some positive results. The majority of studies showed the T administration improved memory and cognition in AD while others did not find any benefit. Although some biases in the studies are evident, T therapy for AD patients may represent an essential clinical therapy to reduce dementia incidence and AD progression. However, more specific case-controlled trials on the effect of androgens therapy in men and women to reducing the onset of AD are necessary.
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Affiliation(s)
- Vittorio Emanuele Bianchi
- Department of Endocrinology and Metabolism, Clinical Research Center Stella Maris, Falciano, San Marino, Italy.
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8
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Elfouly A, Awny M, Ibrahim MK, Aboelsaad M, Tian J, Sayed M. Effects of Long-Acting Testosterone Undecanoate on Behavioral Parameters and Na + , K +-ATPase mRNA Expression in Mice with Alzheimer`s Disease. Neurochem Res 2021; 46:2238-2248. [PMID: 34036518 DOI: 10.1007/s11064-021-03357-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 04/30/2021] [Accepted: 05/15/2021] [Indexed: 01/01/2023]
Abstract
Previous studies have shown that testosterone attenuates stress-induced mood dysfunction and memory deterioration. However, the exact mechanism is still unknown. This study was conducted to investigate the role of long-term testosterone undecanoate on the behavioral responses in AD induced by AlCl3 + D-galactose administration and the possible alteration of the gene expression level of the Na/K ATPase pump. Adult male mice received AlCl3 in drinking water (10 mg/kg/day) and (D-gal 200 mg/kg/day), subcutaneously for 90 consecutive days, then received a single intramuscular (I.M) injection of castor oil (vehicle) on day 91, while treated groups received a single I.M injection of either low (100 mg/kg/45 days) or high dose (500 mg/kg/45 days) respectively of long-acting testosterone undecanoate on day 91. The time spent in the interaction zone during the open field test, preference index to novel objects in the novel object recognition test, spontaneous alternation percentage (SAP) in Y-maze test, and escape latency time in the Morris water maze test were used to measure the locomotor activity, long-term memory, and spatial memory in mice, respectively. The results showed that testosterone undecanoate treatment improved locomotor activity, improved preference to novel objects, improved spatial memory, and reversed anxiety and depression induced by AlCl3 + D-galactose administration in male mice, suggesting the enhancement of behavioral and memory functions brought by testosterone treatment. Moreover, testosterone undecanoate treatment did alter gene expression levels of Na/K ATPase isoforms in the brain hippocampus. In most cases, altered gene expression was significant and correlated with the observed behavioral changes. Taken together, our findings provide new insight into the effects of long-acting testosterone undecanoate administration on locomotor activity, long-term memory, anxiety, and spatial memory in male mice with Alzheimer's disease.
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Affiliation(s)
- A Elfouly
- Department of Pharmacology, Faculty of Pharmacy, October 6Th University, Cairo, Egypt
| | - M Awny
- Department of Pharmacology, Faculty of Pharmacy, October 6Th University, Cairo, Egypt
| | - M K Ibrahim
- Department of Developmental Pharmacology, National Organization for Drug Control and Research (NODCAR), Giza, Egypt
| | - M Aboelsaad
- Department of Clinical Pharmacy Practice, Faculty of Pharmacy, The British University in Egypt, El Shorouk City, Egypt
| | - J Tian
- Department of Biomedical Sciences &, Marshall Institute of Interdisciplinary Research (MIIR), Marshall University, Huntington, WV, USA
| | - M Sayed
- Department of Clinical Pharmacy Practice, Faculty of Pharmacy, The British University in Egypt, El Shorouk City, Egypt. .,Center of Drug Research Development (CDRD), The British University in Egypt, El Shorouk City, Egypt.
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Zhang KJ, Ramdev RA, Tuta NJ, Spritzer MD. Dose-dependent effects of testosterone on spatial learning strategies and brain-derived neurotrophic factor in male rats. Psychoneuroendocrinology 2020; 121:104850. [PMID: 32892065 PMCID: PMC7572628 DOI: 10.1016/j.psyneuen.2020.104850] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 12/15/2022]
Abstract
Studies suggest that males outperform females on some spatial tasks. This may be due to the effects of sex steroids on spatial strategy preferences. Past experiments with male rats have demonstrated that low doses of testosterone bias them toward a response strategy, whereas high doses of testosterone bias them toward a place strategy. We investigated the effect of different testosterone doses on the ability of male rats to effectively employ these two spatial learning strategies. Furthermore, we quantified concentrations of brain-derived neurotrophic factor (pro-, mature-, and total BDNF) in the prefrontal cortex, hippocampus, and striatum. All rats were bilaterally castrated and assigned to one of three daily injection doses of testosterone propionate (0.125, 0.250, or 0.500 mg/rat) or a control injection of the drug vehicle. Using a plus-maze protocol, we found that a lower testosterone dose (0.125 mg) significantly improved rats' performance on a response task, whereas a higher testosterone dose (0.500 mg) significantly improved rats' performance on a place task. In addition, we found that a low dose of testosterone (0.125 mg) increased total BDNF in the striatum, while a high dose (0.500 mg) increased total BDNF in the hippocampus. Taken altogether, these results suggest that high and low levels of testosterone enhance performance on place and response spatial tasks, respectively, and this effect is associated with changes in BDNF levels within relevant brain regions.
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Affiliation(s)
- Kevin J. Zhang
- Department of Biology, Middlebury College, Middlebury, VT 05753, U.S.A
| | - Rajan A. Ramdev
- Program in Neuroscience, Middlebury College, Middlebury, VT 05753, U.S.A
| | - Nicholas J. Tuta
- Program in Neuroscience, Middlebury College, Middlebury, VT 05753, U.S.A
| | - Mark D. Spritzer
- Department of Biology, Middlebury College, Middlebury, VT 05753, U.S.A.,Program in Neuroscience, Middlebury College, Middlebury, VT 05753, U.S.A.,Corresponding author: Mark Spritzer, Department of Biology, McCardell Bicentennial Hall, Middlebury College, Middlebury, VT 05753, USA, phone: 802-443-5676, FAX: 802-443-2072,
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Spritzer MD, Roy EA. Testosterone and Adult Neurogenesis. Biomolecules 2020; 10:biom10020225. [PMID: 32028656 PMCID: PMC7072323 DOI: 10.3390/biom10020225] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/22/2020] [Accepted: 01/28/2020] [Indexed: 12/16/2022] Open
Abstract
It is now well established that neurogenesis occurs throughout adulthood in select brain regions, but the functional significance of adult neurogenesis remains unclear. There is considerable evidence that steroid hormones modulate various stages of adult neurogenesis, and this review provides a focused summary of the effects of testosterone on adult neurogenesis. Initial evidence came from field studies with birds and wild rodent populations. Subsequent experiments with laboratory rodents have tested the effects of testosterone and its steroid metabolites upon adult neurogenesis, as well as the functional consequences of induced changes in neurogenesis. These experiments have provided clear evidence that testosterone increases adult neurogenesis within the dentate gyrus region of the hippocampus through an androgen-dependent pathway. Most evidence indicates that androgens selectively enhance the survival of newly generated neurons, while having little effect on cell proliferation. Whether this is a result of androgens acting directly on receptors of new neurons remains unclear, and indirect routes involving brain-derived neurotrophic factor (BDNF) and glucocorticoids may be involved. In vitro experiments suggest that testosterone has broad-ranging neuroprotective effects, which will be briefly reviewed. A better understanding of the effects of testosterone upon adult neurogenesis could shed light on neurological diseases that show sex differences.
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Affiliation(s)
- Mark D. Spritzer
- Department of Biology, Middlebury College, Middlebury, VT 05753, USA
- Correspondence: ; Tel.: 802-443-5676
| | - Ethan A. Roy
- Graduate School of Education, Stanford University, Stanford, CA 94305, USA;
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