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Orije JEMJ, Van der Linden A. A brain for all seasons: An in vivo MRI perspective on songbirds. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2022; 337:967-984. [PMID: 35989548 PMCID: PMC9804379 DOI: 10.1002/jez.2650] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 07/08/2022] [Accepted: 08/03/2022] [Indexed: 01/05/2023]
Abstract
Seasonality in songbirds includes not only reproduction but also seasonal changes in singing behavior and its neural substrate, the song control system (SCS). Prior research mainly focused on the role of sex steroids on this seasonal SCS neuroplasticity in males. In this review, we summarize the advances made in the field of seasonal neuroplasticity by applying in vivo magnetic resonance imaging (MRI) in male and female starlings, analyzing the entire brain, monitoring birds longitudinally and determining the neuronal correlates of seasonal variations in plasma hormone levels and song behavior. The first MRI studies in songbirds used manganese enhanced MRI to visualize the SCS in a living bird and validated previously described brain volume changes related to different seasons and testosterone. MRI studies with testosterone implantation established how the consequential boost in singing was correlated to structural changes in the SCS, indicating activity-induced neuroplasticity as song proficiency increased. Next, diffusion tensor MRI explored seasonal neuroplasticity in the entire brain, focusing on networks beyond the SCS, revealing that other sensory systems and even the cerebellum, which is important for the integration of sensory perception and song behavior, experience neuroplasticity starting in the photosensitive period. Functional MRI showed that olfactory, and auditory processing was modulated by the seasons. The convergence of seasonal variations in so many sensory and sensorimotor systems resembles multisensory neuroplasticity during the critical period early in life. This sheds new light on seasonal songbirds as a model for unlocking the brain by recreating seasonally the permissive circumstances for heightened neuroplasticity.
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Affiliation(s)
- Jasmien Ellen Maria Jozef Orije
- Department of Biomedical SciencesBio‐Imaging Lab, University of AntwerpAntwerpenBelgium,NEURO Research Centre of Excellence, University of AntwerpAntwerpenBelgium
| | - Annemie Van der Linden
- Department of Biomedical SciencesBio‐Imaging Lab, University of AntwerpAntwerpenBelgium,NEURO Research Centre of Excellence, University of AntwerpAntwerpenBelgium
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2
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Orije JEMJ, Raymaekers SR, Majumdar G, De Groof G, Jonckers E, Ball GF, Verhoye M, Darras VM, Van der Linden A. Unraveling the Role of Thyroid Hormones in Seasonal Neuroplasticity in European Starlings ( Sturnus vulgaris). Front Mol Neurosci 2022; 15:897039. [PMID: 35836548 PMCID: PMC9275473 DOI: 10.3389/fnmol.2022.897039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
Thyroid hormones clearly play a role in the seasonal regulation of reproduction, but any role they might play in song behavior and the associated seasonal neuroplasticity in songbirds remains to be elucidated. To pursue this question, we first established seasonal patterns in the expression of thyroid hormone regulating genes in male European starlings employing in situ hybridization methods. Thyroid hormone transporter LAT1 expression in the song nucleus HVC was elevated during the photosensitive phase, pointing toward an active role of thyroid hormones during this window of possible neuroplasticity. In contrast, DIO3 expression was high in HVC during the photostimulated phase, limiting the possible effect of thyroid hormones to maintain song stability during the breeding season. Next, we studied the effect of hypothyroidism on song behavior and neuroplasticity using in vivo MRI. Both under natural conditions as with methimazole treatment, circulating thyroid hormone levels decreased during the photosensitive period, which coincided with the onset of neuroplasticity. This inverse relationship between thyroid hormones and neuroplasticity was further demonstrated by the negative correlation between plasma T3 and the microstructural changes in several song control nuclei and cerebellum. Furthermore, maintaining hypothyroidism during the photostimulated period inhibited the increase in testosterone, confirming the role of thyroid hormones in activating the hypothalamic-pituitary-gonadal (HPG) axis. The lack of high testosterone levels influenced the song behavior of hypothyroid starlings, while the lack of high plasma T4 during photostimulation affected the myelination of several tracts. Potentially, a global reduction of circulating thyroid hormones during the photosensitive period is necessary to lift the brake on neuroplasticity imposed by the photorefractory period, whereas local fine-tuning of thyroid hormone concentrations through LAT1 could activate underlying neuroplasticity mechanisms. Whereas, an increase in circulating T4 during the photostimulated period potentially influences the myelination of several white matter tracts, which stabilizes the neuroplastic changes. Given the complexity of thyroid hormone effects, this study is a steppingstone to disentangle the influence of thyroid hormones on seasonal neuroplasticity.
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Affiliation(s)
- Jasmien E. M. J. Orije
- Bio-Imaging Lab, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Sander R. Raymaekers
- Laboratory of Comparative Endocrinology, Biology Department, KU Leuven, Leuven, Belgium
| | - Gaurav Majumdar
- Bio-Imaging Lab, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Geert De Groof
- Bio-Imaging Lab, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Elisabeth Jonckers
- Bio-Imaging Lab, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Gregory F. Ball
- Department of Psychology, Neuroscience and Cognitive Science Program, University of Maryland, College Park, College Park, MD, United States
| | - Marleen Verhoye
- Bio-Imaging Lab, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Veerle M. Darras
- Laboratory of Comparative Endocrinology, Biology Department, KU Leuven, Leuven, Belgium
| | - Annemie Van der Linden
- Bio-Imaging Lab, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
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3
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Meng Z, Wang X, Zhang D, Lan Z, Cai X, Bian C, Zhang J. Steroid receptor coactivator-1: The central intermediator linking multiple signals and functions in the brain and spinal cord. Genes Dis 2021; 9:1281-1289. [PMID: 35873031 PMCID: PMC9293692 DOI: 10.1016/j.gendis.2021.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/31/2021] [Accepted: 06/21/2021] [Indexed: 11/28/2022] Open
Abstract
The effects of steroid hormones are believed to be mediated by their nuclear receptors (NRs). The p160 coactivator family, including steroid receptor coactivator-1 (SRC-1), 2 and 3, has been shown to physically interact with NRs to enhance their transactivational activities. Among which SRC-1 has been predominantly localized in the central nervous system including brain and spinal cord. It is not only localized in neurons but also detectable in neuroglial cells (mainly localized in the nuclei but also detectable in the extra-nuclear components). Although the expression of SRC-1 is regulated by many steroids, it is also regulated by some non-steroidal factors such as injury, sound and light. Functionally, SRC-1 has been implied in normal function such as development and ageing, learning and memory, central regulation on reproductive behaviors, motor and food intake. Pathologically, SRC-1 may play a role in the regulation of neuropsychiatric disorders (including stress, depression, anxiety, and autism spectrum disorder), metabolite homeostasis and obesity as well as tumorigenesis. Under most conditions, the related mechanisms are far from elucidation; although it may regulate spatial memory through Rictor/mTORC2-actin polymerization related synaptic plasticity. Several inhibitors and stimulator of SRC-1 have shown anti-cancer potentials, but whether these small molecules could be used to modulate ageing and central disorder related neuropathology remain unclear. Therefore, to elucidate when and how SRC-1 is turned on and off under different stimuli is very interesting and great challenge for neuroscientists.
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Affiliation(s)
- Zhaoyou Meng
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
| | - Xiaoya Wang
- Department of Neurosurgery, Nanchong Central Hospital, the Second Clinical Medical College, North Sichuan Medical College, Nanchong, Sichuan 637000, PR China
| | - Dongmei Zhang
- Department of Dermatology, Southwest Hospital, Army Medical University, Chongqing 400038, PR China
| | - Zhen Lan
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
| | - Xiaoxia Cai
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
- School of Life Sciences, Southwest University, Chongqing 400715, PR China
| | - Chen Bian
- School of Psychology, Amy Medical University, Chongqing 400038, PR China
- Corresponding author.
| | - Jiqiang Zhang
- Department of Neurobiology, Army Medical University, Chongqing 400038, PR China
- Corresponding author.
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Gessara I, Dittrich F, Hertel M, Hildebrand S, Pfeifer A, Frankl-Vilches C, McGrew M, Gahr M. Highly Efficient Genome Modification of Cultured Primordial Germ Cells with Lentiviral Vectors to Generate Transgenic Songbirds. Stem Cell Reports 2021; 16:784-796. [PMID: 33740464 PMCID: PMC8072032 DOI: 10.1016/j.stemcr.2021.02.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/13/2022] Open
Abstract
The ability to genetically manipulate organisms has led to significant insights into functional genomics in many species. In birds, manipulation of the genome is hindered by the inaccessibility of the one-cell embryo. During embryonic development, avian primordial germ cells (PGCs) migrate through the bloodstream and reach the gonadal anlage, where they develop into mature germ cells. Here, we explored the use of PGCs to produce transgenic offspring in the zebra finch, which is a major animal model for sexual brain differentiation, vocal learning, and vocal communication. Zebra finch PGCs (zfPGCs) obtained from embryonic blood significantly proliferated when cultured in an optimized culture medium and conserved the expression of germ and stem cell markers. Transduction of cultured zfPGCs with lentiviral vectors was highly efficient, leading to strong expression of the enhanced green fluorescent protein. Transduced zfPGCs were injected into the host embryo and transgenic songbirds were successfully generated.
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Affiliation(s)
- Ivana Gessara
- Max Planck Institute for Ornithology, Eberhard Gwinner Strasse, 82319 Seewiesen, Germany.
| | - Falk Dittrich
- Max Planck Institute for Ornithology, Eberhard Gwinner Strasse, 82319 Seewiesen, Germany
| | - Moritz Hertel
- Max Planck Institute for Ornithology, Eberhard Gwinner Strasse, 82319 Seewiesen, Germany
| | - Staffan Hildebrand
- Institute of Pharmacology and Toxicology, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Alexander Pfeifer
- Institute of Pharmacology and Toxicology, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | | | - Mike McGrew
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK
| | - Manfred Gahr
- Max Planck Institute for Ornithology, Eberhard Gwinner Strasse, 82319 Seewiesen, Germany
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Villavicencio CP, Windley H, D'Amelio PB, Gahr M, Goymann W, Quispe R. Neuroendocrine patterns underlying seasonal song and year-round territoriality in male black redstarts. Front Zool 2021; 18:8. [PMID: 33627161 PMCID: PMC7905601 DOI: 10.1186/s12983-021-00389-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 02/01/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The connection between testosterone and territoriality in free-living songbirds has been well studied in a reproductive context, but less so outside the breeding season. To assess the effects of seasonal androgenic action on territorial behavior, we analyzed vocal and non-vocal territorial behavior in response to simulated territorial intrusions (STIs) during three life-cycle stages in free-living male black redstarts: breeding, molt and nonbreeding. Concurrently, we measured changes in circulating testosterone levels, as well as the mRNA expression of androgen and estrogen receptors and aromatase in the preoptic, hypothalamic and song control brain areas that are associated with social and vocal behaviors. RESULTS Territorial behavior and estrogen receptor expression in hypothalamic areas did not differ between stages. But plasma testosterone was higher during breeding than during the other stages, similar to androgen receptor and aromatase expression in the preoptic area. The expression of androgen receptors in the song control nucleus HVC was lower during molt when birds do not sing or sing rarely, but similar between the breeding and the nonbreeding stage. Nevertheless, some song spectral features and the song repertoire differed between breeding and nonbreeding. Territorial behavior and song rate correlated with the expression of steroid receptors in hypothalamic areas, and in the song control nucleus lMAN. CONCLUSIONS Our results demonstrate seasonal modulation of song, circulating testosterone levels, and brain sensitivity to androgens, but a year-round persistency of territorial behavior and estrogen receptor expression in all life-cycle stages. This suggests that seasonal variations in circulating testosterone concentrations and brain sensitivity to androgens is widely uncoupled from territorial behavior and song activity but might still affect song pattern. Our study contributes to the understanding of the complex comparative neuroendocrinology of song birds in the wild.
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Affiliation(s)
- Camila P Villavicencio
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany. .,Department of Ecological Science, Institute of Ecology and Biodiversity, Faculty of Science, University of Chile, Las Palmeras 3425, Ñuñoa, Santiago, Chile.
| | - Harriet Windley
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany
| | - Pietro B D'Amelio
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany.,FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, 7701, South Africa
| | - Manfred Gahr
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany
| | - Wolfgang Goymann
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany
| | - René Quispe
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany.,Department of Marine Biology, Faculty of Ocean Sciences, Universidad Catolica del Norte (UCN), Larrondo 1281, Coquimbo, Chile
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6
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Pimentel HDC, Macêdo-Lima M, Viola GG, Melleu FF, Dos Santos TS, Franco HS, da Silva RDS, Lino-de-Oliveira C, Marino-Neto J, Dos Santos JR, Marchioro M. Telencephalic distributions of doublecortin and glial fibrillary acidic protein suggest novel migratory pathways in adult lizards. J Chem Neuroanat 2020; 112:101901. [PMID: 33271217 DOI: 10.1016/j.jchemneu.2020.101901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/26/2020] [Accepted: 11/26/2020] [Indexed: 11/30/2022]
Abstract
Adult neurogenesis has been reported in all major vertebrate taxa. However, neurogenic rates and the number of neurogenic foci vary greatly, and are higher in ancestral taxa. Our study aimed to evaluate the distribution of doublecortin (DCX) and glial fibrillary acidic protein (GFAP) in telencephalic areas of the adult tropical lizard Tropidurus hispidus. We describe evidence for four main neurogenic foci, which coincide anatomically with the ventricular sulci described by the literature. Based on neuronal morphology, we infer four migratory patterns/pathways. In the cortex, patterns of GFAP and DCX staining support radial migrations from ventricular zones into cortical areas and dorsoventricular ridge. Cells radiating from the sulcus septomedialis (SM) seemed to migrate to the medial cortex and dorsal cortex. From the sulcus lateralis (SL), they seemed to be bound for the lateral cortex, central amygdala and nucleus sphericus. We describe a DCX-positive stream originating in the caudal sulcus ventralis and seemingly bound for the olfactory bulb, resembling a rostral migratory stream. We provide evidence for a previously undescribed tangential dorso-septo-caudal migratory stream, with neuroblasts supported by DCX-positive fibers. Finally, we provide evidence for a commissural migration stream seemingly bound for the contralateral nucleus sphericus. Therefore, in addition to two previously known migratory streams, this study provides anatomical evidence in support for two novel migratory routes in amniotes.
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Affiliation(s)
- Hugo de C Pimentel
- Laboratory of Neurophysiology, Department of Physiology, Federal University of Sergipe, São Cristovão, SE, Brazil
| | - Matheus Macêdo-Lima
- Center for Neuroendocrine Studies, University of Massachusetts Amherst, Amherst, MA, USA
| | - Giordano G Viola
- Laboratory of Neurophysiology, Department of Physiology, Federal University of Sergipe, São Cristovão, SE, Brazil
| | - Fernando F Melleu
- Department of Physiological Sciences, Federal University of Santa Catarina, SC, Brazil
| | - Tiago S Dos Santos
- Department of Physiological Sciences, Federal University of Santa Catarina, SC, Brazil
| | - Heitor S Franco
- Laboratory of Behavioral and Evolutionary Neurobiology, Department of Biosciences, Federal University of Sergipe, Itabaiana, SE, Brazil
| | - Rodolfo Dos S da Silva
- Laboratory of Behavioral and Evolutionary Neurobiology, Department of Biosciences, Federal University of Sergipe, Itabaiana, SE, Brazil
| | | | - José Marino-Neto
- Department of Physiological Sciences, Federal University of Santa Catarina, SC, Brazil
| | - José R Dos Santos
- Laboratory of Behavioral and Evolutionary Neurobiology, Department of Biosciences, Federal University of Sergipe, Itabaiana, SE, Brazil.
| | - Murilo Marchioro
- Laboratory of Neurophysiology, Department of Physiology, Federal University of Sergipe, São Cristovão, SE, Brazil.
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Ko MC, Van Meir V, Vellema M, Gahr M. Characteristics of song, brain-anatomy and blood androgen levels in spontaneously singing female canaries. Horm Behav 2020; 117:104614. [PMID: 31647922 DOI: 10.1016/j.yhbeh.2019.104614] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 10/08/2019] [Accepted: 10/08/2019] [Indexed: 12/24/2022]
Abstract
Females of many northern temperate songbird species sing sporadically. However, detailed descriptions of female song are rare. Here we report a detailed analysis of song in a small number of spontaneously-singing female domesticated canaries (Serinus canaria) under non-breeding, laboratory conditions in a large population of domesticated birds. In-depth analysis showed that these females sang rarely, and the spontaneous songs varied between and within birds over time. Furthermore, spontaneous female songs were distinct from songs of testosterone-induced singing female canaries and from songs of male canaries in both temporal and spectral features. Singing females had significantly elevated plasma androgen levels and a larger size of the major song controlling brain nuclei HVC (used as a proper name) and the robust nucleus of the arcopallium (RA) than non-singing females housed under similar conditions. The sporadically observed production of song and accompanying differences in brain anatomy in female canaries may thus depend on minute intraspecific differences in androgen levels.
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Affiliation(s)
- Meng-Ching Ko
- Max Planck Institute for Ornithology, Dept. of Behavioural Neurobiology, Eberhard-Gwinner str. 6a, 82319 Seewiesen, Germany.
| | - Vincent Van Meir
- Max Planck Institute for Ornithology, Dept. of Behavioural Neurobiology, Eberhard-Gwinner str. 6a, 82319 Seewiesen, Germany
| | - Michiel Vellema
- Utrecht University, Dept. of Experimental Psychology, Yalelaan 2, 3584, CM, Utrecht, the Netherlands
| | - Manfred Gahr
- Max Planck Institute for Ornithology, Dept. of Behavioural Neurobiology, Eberhard-Gwinner str. 6a, 82319 Seewiesen, Germany
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8
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Okubo K, Miyazoe D, Nishiike Y. A conceptual framework for understanding sexual differentiation of the teleost brain. Gen Comp Endocrinol 2019; 284:113129. [PMID: 30825478 DOI: 10.1016/j.ygcen.2019.02.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/08/2019] [Accepted: 02/26/2019] [Indexed: 12/31/2022]
Abstract
Vertebrate brains are sexually differentiated, giving rise to differences in various physiological and behavioral phenotypes between the sexes. In developing mammals and birds, the neural substrate underlying sex-dependent physiology and behavior undergoes an irreversible process of sexual differentiation due to the effects of perinatal gonadal steroids and sex chromosome complement. The differentiated neural substrate is then activated in the adult by the sex-specific steroid milieu to facilitate the expression of sex-typical phenotypes. However, this well-established concept does not hold for teleost fish, whose sexual phenotypes (behavioral or otherwise) are highly labile throughout life and can be reversed even in adulthood. Indeed, the available evidence suggests that, in teleosts, neither gonadal steroids early in development nor the sex chromosome complement contribute much to brain sexual differentiation; instead, steroids in adulthood serve to both differentiate the neural substrate and activate it to elicit sex-typical phenotypes in a transient and reversible manner. Evidence further suggests that marked sexual dimorphisms and adult steroid-dependent lability in the neural expression of sex steroid receptors constitute the primary molecular basis for sexual differentiation and lability of the teleost brain. The consequent sexually dimorphic but reversible steroid sensitivity in response to the adult steroid milieu may enable the teleost brain to maintain lifelong sexual lability and to undergo phenotypic sex reversal.
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Affiliation(s)
- Kataaki Okubo
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
| | - Daichi Miyazoe
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan
| | - Yuji Nishiike
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan
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9
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Lumineau S, Pawluski JL, Charlier TD, Beylard A, Aigueperse N, Bertin A, Lévy F. High social motivation induces deficits in maternal behaviour but not plasticity of the subventricular zone in Japanese quail (Coturnix japonica). J Neuroendocrinol 2019; 31:e12716. [PMID: 30927275 DOI: 10.1111/jne.12716] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 03/15/2019] [Accepted: 03/26/2019] [Indexed: 12/13/2022]
Abstract
Maternal behaviour develops differently depending on the characteristics of an individual, such as age or emotional reactivity. Social motivation, defined as the propensity to establish social contact, has received little attention in relation to maternal behaviour in birds. In addition, the transition to motherhood is a time of plasticity in the brain of the new mother in mammals. However, it remains to be determined how maternal brain plasticity is affected in avian species. The present study investigated how a the social motivation of a mother alters maternal behaviour and brain plasticity of the Japanese quail (Coturnix japonica). Adult females from lines selected for high and low social motivation were exposed to chicks for 11 days. After maternal care testing, and at matched time points in controls, the brains of females were perfused for assessment of doublecortin-immunoreactive staining, a marker of neurogenesis, in the subventricular zone (SVZ), a neurogenic niche. The results obtained showed that high socially motivated female quail spent significantly less time performing maternal behaviour when exposed to chicks compared to low socially motivated females. Moreover, the warming of chicks by high socially motivated females involved less covering postures and mothers were more rejecting of chicks. Interestingly, the plasticity indicators in the SVZ did not differ between low and high socially motivated females and were not associated with differences in maternal caregiving when using doublecortin-immunoreactive staining. Thus, high social motivation in this avian species does not favour maternal behaviour and this level of motivation to the mother is not related to changes in neuroplasticity in the SVZ of the female quail.
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Affiliation(s)
- Sophie Lumineau
- CNRS, Ethos (Ethologie animale et humaine), UMR 6552, Univ Rennes, Normandie Univ, Rennes, France
| | - Jodi L Pawluski
- Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Univ Rennes, Rennes, France
| | - Thierry D Charlier
- Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Univ Rennes, Rennes, France
| | - Amandine Beylard
- CNRS, Ethos (Ethologie animale et humaine), UMR 6552, Univ Rennes, Normandie Univ, Rennes, France
| | - Nadège Aigueperse
- CNRS, Ethos (Ethologie animale et humaine), UMR 6552, Univ Rennes, Normandie Univ, Rennes, France
| | - Aline Bertin
- Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Univ Rennes, Rennes, France
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, CNRS, UMR 7247, IFCE, Université F. Rabelais, Nouzilly, France
| | - Frédéric Lévy
- Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Univ Rennes, Rennes, France
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, CNRS, UMR 7247, IFCE, Université F. Rabelais, Nouzilly, France
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10
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Herold C, Schlömer P, Mafoppa-Fomat I, Mehlhorn J, Amunts K, Axer M. The hippocampus of birds in a view of evolutionary connectomics. Cortex 2019; 118:165-187. [DOI: 10.1016/j.cortex.2018.09.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/26/2018] [Accepted: 09/26/2018] [Indexed: 12/12/2022]
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11
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Hiraki-Kajiyama T, Yamashita J, Yokoyama K, Kikuchi Y, Nakajo M, Miyazoe D, Nishiike Y, Ishikawa K, Hosono K, Kawabata-Sakata Y, Ansai S, Kinoshita M, Nagahama Y, Okubo K. Neuropeptide B mediates female sexual receptivity in medaka fish, acting in a female-specific but reversible manner. eLife 2019; 8:39495. [PMID: 31383257 PMCID: PMC6684226 DOI: 10.7554/elife.39495] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 07/18/2019] [Indexed: 12/28/2022] Open
Abstract
Male and female animals display innate sex-specific mating behaviors. In teleost fish, altering the adult sex steroid milieu can effectively reverse sex-typical mating behaviors, suggesting remarkable sexual lability of their brains as adults. In the teleost medaka, neuropeptide B (NPB) is expressed female-specifically in the brain nuclei implicated in mating behavior. Here, we demonstrate that NPB is a direct mediator of estrogen action on female mating behavior, acting in a female-specific but reversible manner. Analysis of regulatory mechanisms revealed that the female-specific expression of NPB is dependent on direct transcriptional activation by estrogen via an estrogen-responsive element and is reversed in response to changes in the adult sex steroid milieu. Behavioral studies of NPB knockouts revealed that female-specific NBP mediates female receptivity to male courtship. The female-specific NPB signaling identified herein is presumably a critical element of the neural circuitry underlying sexual dimorphism and lability of mating behaviors in teleosts.
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Affiliation(s)
- Towako Hiraki-Kajiyama
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Laboratory for Systems Molecular Ethology, RIKEN Center for Brain Science, Wako, Japan
| | - Junpei Yamashita
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Keiko Yokoyama
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yukiko Kikuchi
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Mikoto Nakajo
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Daichi Miyazoe
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yuji Nishiike
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kaito Ishikawa
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kohei Hosono
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yukika Kawabata-Sakata
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Satoshi Ansai
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.,Laboratory of Bioresources, National Institute for Basic Biology, Okazaki, Japan
| | - Masato Kinoshita
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Yoshitaka Nagahama
- Division of Reproductive Biology, National Institute for Basic Biology, Okazaki, Japan
| | - Kataaki Okubo
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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12
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Kikuchi Y, Hiraki-Kajiyama T, Nakajo M, Umatani C, Kanda S, Oka Y, Matsumoto K, Ozawa H, Okubo K. Sexually Dimorphic Neuropeptide B Neurons in Medaka Exhibit Activated Cellular Phenotypes Dependent on Estrogen. Endocrinology 2019; 160:827-839. [PMID: 30776298 DOI: 10.1210/en.2019-00030] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 02/13/2019] [Indexed: 12/22/2022]
Abstract
Brain and behavior of teleosts are highly sexually plastic throughout life, yet the underlying neural mechanisms are largely unknown. On examining brain morphology in the teleost medaka (Oryzias latipes), we identified distinctively large neurons in the magnocellular preoptic nucleus that occurred much more abundantly in females than in males. Examination of sex-reversed medaka showed that the sexually dimorphic abundance of these neurons is dependent on gonadal phenotype, but independent of sex chromosome complement. Most of these neurons in females, but none in males, produced neuropeptide B (Npb), whose expression is known to be estrogen-dependent and associated with female sexual receptivity. In phenotypic analysis, the female-specific Npb neurons had a large euchromatic nucleus with an abundant cytoplasm containing plentiful rough endoplasmic reticulum, exhibited increased overall transcriptional activity, and typically displayed a spontaneous regular firing pattern. These phenotypes, which are probably indicative of cellular activation, were attenuated by ovariectomy and restored by estrogen replacement. Furthermore, the population of Npb-expressing neurons emerged in adult males treated with estrogen, not through frequently occurring neurogenesis in the adult teleost brain, but through the activation of preexisting, quiescent male counterpart neurons. Collectively, our results demonstrate that the morphological, transcriptional, and electrophysiological phenotypes of sexually dimorphic preoptic Npb neurons are highly dependent on estrogen and can be switched between female and male patterns. These properties of the preoptic Npb neurons presumably underpin the neural mechanism for sexual differentiation and plasticity of brain and behavior in teleosts.
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Affiliation(s)
- Yukiko Kikuchi
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Towako Hiraki-Kajiyama
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
- Laboratory for Systems Molecular Ethology, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Mikoto Nakajo
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Chie Umatani
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Shinji Kanda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Yoshitaka Oka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Keisuke Matsumoto
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Bunkyo, Tokyo, Japan
| | - Hitoshi Ozawa
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Nippon Medical School, Bunkyo, Tokyo, Japan
| | - Kataaki Okubo
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
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13
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Nkomozepi P, Mazengenya P, Ihunwo AO. Quantitative analysis of age and life-history stage related changes in DCX expression in the male Japanese quail (Cortunix japonica) telencephalon. Int J Dev Neurosci 2019; 74:38-48. [PMID: 30890437 DOI: 10.1016/j.ijdevneu.2019.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/23/2019] [Accepted: 03/11/2019] [Indexed: 12/22/2022] Open
Abstract
Most avian neurogenesis studies focused on the song control system and little attention has been given to non-song birds such as the Japanese quail. However, the only few neurogenesis studies in quails mainly focused on the sex steroid sensitive areas of the brain such as the medial preoptic and lateral septal nuclei. Despite the important role the quail telencephalon plays in filial imprinting and passive avoidance learning, neurogenesis in this structure has been completely overlooked. The aim of this study was therefore to quantitatively determine how DCX expression in the Japanese quail telencephalon changes with post hatching age (3-12 weeks) and life history stage. In this study, DCX was used as a proxy for neuronal incorporation. Bipolar and multipolar DCX immunoreactive cells were observed in the entire telencephalon except for the entopallium and arcopallium. In addition, DCX expression in all the eight telencephalic areas quantified was strongly negatively correlated with post-hatching age. Furthermore, numbers of bipolar and multipolar DCX immunoreactive cells were higher in the juvenile compared to subadult and adult quails. In conclusion, neuronal incorporation in the quail telencephalon is widespread but it declines with post hatching age. In addition, the most dramatic decline in neuronal incorporation in the telencephalic areas quantified takes place just after the birds have attained sexual maturity.
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Affiliation(s)
- Pilani Nkomozepi
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa; Department of Human Anatomy & Physiology, University of Johannesburg, Cnr Siemert and Beit Streets, Doornfontein, Johannesburg, 2094, South Africa
| | - Pedzisai Mazengenya
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa
| | - Amadi O Ihunwo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193, South Africa.
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14
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Mazengenya P, Bhagwandin A, Manger PR, Ihunwo AO. Putative Adult Neurogenesis in Old World Parrots: The Congo African Grey Parrot ( Psittacus erithacus) and Timneh Grey Parrot ( Psittacus timneh). Front Neuroanat 2018; 12:7. [PMID: 29487507 PMCID: PMC5816827 DOI: 10.3389/fnana.2018.00007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 01/15/2018] [Indexed: 11/21/2022] Open
Abstract
In the current study, we examined for the first time, the potential for adult neurogenesis throughout the brain of the Congo African grey parrot (Psittacus erithacus) and Timneh grey parrot (Psittacus timneh) using immunohistochemistry for the endogenous markers proliferating cell nuclear antigen (PCNA), which labels proliferating cells, and doublecortin (DCX), which stains immature and migrating neurons. A similar distribution of PCNA and DCX immunoreactivity was found throughout the brain of the Congo African grey and Timneh grey parrots, but minor differences were also observed. In both species of parrots, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, subventricular zone of the lateral wall of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and the rhombencephalon. The olfactory bulb and telencephalic subdivisions exhibited a higher density of both PCNA and DCX immunoreactive cells than any other brain region. DCX immunoreactive staining was stronger in the telencephalon than in the subtelencephalic structures. There was evidence of proliferative hot spots in the dorsal and ventral poles of the lateral ventricle in the Congo African grey parrots at rostral levels, whereas only the dorsal accumulation of proliferating cells was observed in the Timneh grey parrot. In most pallial regions the density of PCNA and DCX stained cells increased from rostral to caudal levels with the densest staining in the nidopallium caudolaterale (NCL). The widespread distribution of PCNA and DCX in the brains of both parrot species suggest the importance of adult neurogenesis and neuronal plasticity during learning and adaptation to external environmental variations.
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Affiliation(s)
- Pedzisai Mazengenya
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Amadi O Ihunwo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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15
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Nkomozepi P, Mazengenya P, Ihunwo AO. Changes in neurogenesis with post-hatching age in the male Japanese quail (Cortunix japonica) brain. Acta Neurobiol Exp (Wars) 2018. [DOI: 10.21307/ane-2018-016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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Anand SK, Mondal AC. Cellular and molecular attributes of neural stem cell niches in adult zebrafish brain. Dev Neurobiol 2017; 77:1188-1205. [PMID: 28589616 DOI: 10.1002/dneu.22508] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 04/05/2017] [Accepted: 06/02/2017] [Indexed: 12/20/2022]
Abstract
Adult neurogenesis is a complex, presumably conserved phenomenon in vertebrates with a broad range of variations regarding neural progenitor/stem cell niches, cellular composition of these niches, migratory patterns of progenitors and so forth among different species. Current understanding of the reasons underlying the inter-species differences in adult neurogenic potential, the identification and characterization of various neural progenitors, characterization of the permissive environment of neural stem cell niches and other important aspects of adult neurogenesis is insufficient. In the last decade, zebrafish has emerged as a very useful model for addressing these questions. In this review, we have discussed the present knowledge regarding the neural stem cell niches in adult zebrafish brain as well as their cellular and molecular attributes. We have also highlighted their similarities and differences with other vertebrate species. In the end, we shed light on some of the known intrinsic and extrinsic factors that are assumed to regulate the neurogenic process in adult zebrafish brain. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1188-1205, 2017.
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Affiliation(s)
- Surendra Kumar Anand
- Cellular and Molecular Neurobiology Lab, School of Life Sciences, Jawaharlal Nehru University, New Mehrauli Road, New Delhi, India, 110067
| | - Amal Chandra Mondal
- Cellular and Molecular Neurobiology Lab, School of Life Sciences, Jawaharlal Nehru University, New Mehrauli Road, New Delhi, India, 110067
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17
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Mazengenya P, Bhagwandin A, Nkomozepi P, Manger PR, Ihunwo AO. Putative adult neurogenesis in two domestic pigeon breeds (Columba livia domestica): racing homer versus utility carneau pigeons. Neural Regen Res 2017; 12:1086-1096. [PMID: 28852390 PMCID: PMC5558487 DOI: 10.4103/1673-5374.211187] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Generation of neurons in the brains of adult birds has been studied extensively in the telencephalon of song birds and few studies are reported on the distribution of PCNA and DCX in the telencephalon of adult non-song learning birds. We report here on adult neurogenesis throughout the brains of two breeds of adult domestic pigeons (Columba livia domestica), the racing homer and utility carneau using endogenous immunohistochemical markers proliferating cell nuclear antigen (PCNA) for proliferating cells and doublecortin (DCX) for immature and migrating neurons. The distribution of PCNA and DCX immunoreactivity was very similar in both pigeon breeds with only a few minor differences. In both pigeons, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, walls of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and cerebellum. Generally, the olfactory bulbs and telencephalon had more PCNA and DCX cells than other regions. Two proliferative hotspots were evident in the dorsal and ventral poles of the lateral ventricles. PCNA- and DCX-immunoreactive cells migrated radially from the walls of the lateral ventricle into the parenchyma. In most telencephalic regions, the density of PCNA- and DCX-immunoreactive cells increased from rostral to caudal, except in the mesopallium where the density decreased from rostral to middle levels and then increased caudally. DCX immunoreactivity was more intense in fibres than in cell bodies and DCX-immunoreactive cells included small granular cells, fusiform bipolar cells, large round and or polygonal multipolar cells. The similarity in the distribution of proliferating cells and new neurons in the telencephalon of the two breeds of pigeons may suggest that adult neurogenesis is a conserved trait as an ecological adaptation irrespective of body size.
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Affiliation(s)
- Pedzisai Mazengenya
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Pilani Nkomozepi
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Amadi O Ihunwo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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18
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A comparative study of sex difference in calbindin neurons among mice, musk shrews, and Japanese quails. Neurosci Lett 2016; 631:63-69. [DOI: 10.1016/j.neulet.2016.08.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 08/11/2016] [Accepted: 08/12/2016] [Indexed: 11/19/2022]
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19
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Powers AS. Plasticity and Adult Neurogenesis in Amphibians and Reptiles: More Questions than Answers. BRAIN, BEHAVIOR AND EVOLUTION 2016; 87:175-183. [DOI: 10.1159/000447047] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Studies of the relationship between behavioral plasticity and new cells in the adult brain in amphibians and reptiles are sparse but demonstrate that environmental and hormonal variables do have an effect on the amount of cell proliferation and/or migration. The variables that are reviewed here are: enriched environment, social stimulation, spatial area use, season, photoperiod and temperature, and testosterone. Fewer data are available for amphibians than for reptiles, but for both groups many issues are still to be resolved. It is to be hoped that the questions raised here will generate more answers in future studies.
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20
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Balthazart J, Ball GF. Endocrine and social regulation of adult neurogenesis in songbirds. Front Neuroendocrinol 2016; 41:3-22. [PMID: 26996818 DOI: 10.1016/j.yfrne.2016.03.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 03/16/2016] [Accepted: 03/16/2016] [Indexed: 01/07/2023]
Abstract
The identification of pronounced seasonal changes in the volume of avian song control nuclei stimulated the discovery of adult neurogenesis in songbirds as well as renewed studies in mammals including humans. Neurogenesis in songbirds is modulated by testosterone and other factors such as photoperiod, singing activity and social environment. Adult neurogenesis has been widely studied by labeling, with tritiated thymidine or its analog BrdU, cells duplicating their DNA in anticipation of their last mitotic division and following their fate as new neurons. New methods based on endogenous markers of cell cycling or of various stages of neuronal life have allowed for additional progress. In particular immunocytochemical visualization of the microtubule-associated protein doublecortin has provided an integrated view of neuronal replacement in the song control nucleus HVC. Multiple questions remain however concerning the specific steps in the neuronal life cycle that are modulated by various factors and the underlying cellular mechanisms.
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Affiliation(s)
| | - Gregory F Ball
- Department of Psychology, University of Maryland, College Park, College Park, MD, USA.
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21
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Defensive behaviors and prosencephalic neurogenesis in pigeons (Columba livia) are affected by environmental enrichment in adulthood. Brain Struct Funct 2015; 221:2287-301. [DOI: 10.1007/s00429-015-1043-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 04/06/2015] [Indexed: 01/04/2023]
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22
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"Seasonal changes in the neuroendocrine system": some reflections. Front Neuroendocrinol 2015; 37:3-12. [PMID: 25462591 DOI: 10.1016/j.yfrne.2014.11.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 11/13/2014] [Accepted: 11/13/2014] [Indexed: 12/12/2022]
Abstract
This perspective considers first the general issue of seasonality and how it is shaped ecologically. It asks what is the relative importance of "strategic" (photoperiod-dependent) versus "tactical" (supplemental) cues in seasonality and what neural circuits are involved? It then considers recent developments as reflected in the Special Issue. What don't we understand about the photoperiodic clock and also the long-term timing mechanisms underlying refractoriness? Are these latter related to the endogenous annual rhythms? Can we finally identify the opsins involved in photodetection? What is the present position with regard to melatonin as "the" annual calendar? An exciting development has been the recognition of the involvement of thyroid hormones in seasonality but how does the Dio/TSH/thyroid hormone pathway integrate with downstream components of the photoperiodic response system? Finally, there are the seasonal changes within the central nervous system itself--perhaps the most exciting aspect of all.
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23
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Brenowitz EA. Transsynaptic trophic effects of steroid hormones in an avian model of adult brain plasticity. Front Neuroendocrinol 2015; 37:119-28. [PMID: 25285401 PMCID: PMC4385747 DOI: 10.1016/j.yfrne.2014.09.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/16/2014] [Accepted: 09/22/2014] [Indexed: 12/23/2022]
Abstract
The avian song control system provides an excellent model for studying transsynaptic trophic effects of steroid sex hormones. Seasonal changes in systemic testosterone (T) and its metabolites regulate plasticity of this system. Steroids interact with the neurotrophin brain-derived neurotrophic factor (BDNF) to influence cellular processes of plasticity in nucleus HVC of adult birds, including the addition of newborn neurons. This interaction may also occur transsynpatically; T increases the synthesis of BDNF in HVC, and BDNF protein is then released by HVC neurons on to postsynaptic cells in nucleus RA where it has trophic effects on activity and morphology. Androgen action on RA neurons increases their activity and this has a retrograde trophic effect on the addition of new neurons to HVC. The functional linkage of sex steroids to BDNF may be of adaptive value in regulating the trophic effects of the neurotrophin and coordinating circuit function in reproductively relevant contexts.
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Affiliation(s)
- Eliot A Brenowitz
- Departments of Psychology and Biology, and the Virginia Merrill Bloedel Hearing Research Center, University of Washington, United States.
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24
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Wong RY, Cummings ME. Expression Patterns of Neuroligin-3 and Tyrosine Hydroxylase across the Brain in Mate Choice Contexts in Female Swordtails. BRAIN, BEHAVIOR AND EVOLUTION 2014; 83:231-43. [DOI: 10.1159/000360071] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 01/24/2014] [Indexed: 11/19/2022]
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25
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Cordes MA, Stevenson SA, Riters LV. Status-appropriate singing behavior, testosterone and androgen receptor immunolabeling in male European starlings (Sturnus vulgaris). Horm Behav 2014; 65:329-39. [PMID: 24594286 PMCID: PMC4010097 DOI: 10.1016/j.yhbeh.2014.02.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 02/22/2014] [Accepted: 02/24/2014] [Indexed: 12/27/2022]
Abstract
Vocalizations convey information about an individual's motivational, internal, and social status. As circumstances change, individuals respond by adjusting vocal behavior accordingly. In European starlings, a male that acquires a nest site socially dominates other males and dramatically increases courtship song. Although circulating testosterone is associated with social status and vocal production it is possible that steroid receptors fine-tune status-appropriate changes in behavior. Here we explored a possible role for androgen receptors. Male starlings that acquired nest sites produced high rates of courtship song. For a subset of males this occurred even in the absence of elevated circulating testosterone. Immunolabeling for androgen receptors (ARir) was highest in the medial preoptic nucleus (POM) in males with both a nest site and elevated testosterone. For HVC, ARir was higher in dominant males with high testosterone (males that sang longer songs) than dominant males with low testosterone (males that sang shorter songs). ARir in the dorsal medial portion of the nucleus intercollicularis (DM) was elevated in males with high testosterone irrespective of dominance status. Song bout length related positively to ARir in POM, HVC and DM, and testosterone concentrations related positively to ARir in POM and DM. Results suggest that the role of testosterone in vocal behavior differs across brain regions and support the hypothesis that testosterone in POM underlies motivation, testosterone in HVC relates to song quality, and testosterone in DM stimulates vocalizations. Our data also suggest that singing may influence AR independent of testosterone and that alternative androgen-independent pathways regulate status-appropriate singing behavior.
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Affiliation(s)
- M A Cordes
- Department of Zoology, University of Wisconsin, Madison 53706, USA.
| | - S A Stevenson
- Department of Zoology, University of Wisconsin, Madison 53706, USA
| | - L V Riters
- Department of Zoology, University of Wisconsin, Madison 53706, USA
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26
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Vergauwen J, Groothuis TGG, Eens M, Müller W. Testosterone influences song behaviour and social dominance - but independent of prenatal yolk testosterone exposure. Gen Comp Endocrinol 2014; 195:80-7. [PMID: 24211320 DOI: 10.1016/j.ygcen.2013.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 09/03/2013] [Accepted: 10/17/2013] [Indexed: 01/23/2023]
Abstract
In the last two decades, maternally derived yolk androgens have been shown to significantly alter offspring development, and a number of these effects persist into adulthood. However, little is known about their underlying mechanisms. Mechanisms that have been suggested are changes in the endogenous androgen production post-hatching or changes in the sensitivity towards circulating androgens. We tested the effects of yolk testosterone on the plasma testosterone levels and the sensitivity to testosterone in 5months old male canaries that hatched from eggs that were either injected with testosterone (yT-males) or with a control solution (yC-males). Changes in sensitivity were investigated via the behavioural response to an experimental elevation of the plasma testosterone levels. We performed the experiment in fall (low endogenous testosterone production), focusing on testosterone dependent response traits (aggression and song). Before implantation, there was a non-significant trend that the plasma testosterone levels were lower in yT-males than in yC-males. Elevating the plasma testosterone concentrations increased aggressiveness, song bout length and similarity of repeated song elements (=consistency), with the latter likely being a consequence of testosterone-driven song crystallization. However, these effects were not different among yT- or yC-males in any of the parameters. Thus, our findings render it unlikely that changes in the sensitivity to testosterone post-hatching would form the main underlying mechanism of hormone-mediated maternal effects in birds. Further experiments are urgently needed in order to understand the nature of the phenotypic effects resulting from embryonic exposure to maternal yolk testosterone.
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Affiliation(s)
- Jonas Vergauwen
- Department of Biology - Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Ton G G Groothuis
- Department of Behavioural Biology, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands
| | - Marcel Eens
- Department of Biology - Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Wendt Müller
- Department of Biology - Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
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27
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Cassone VM. Avian circadian organization: a chorus of clocks. Front Neuroendocrinol 2014; 35:76-88. [PMID: 24157655 PMCID: PMC3946898 DOI: 10.1016/j.yfrne.2013.10.002] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 07/18/2013] [Accepted: 10/09/2013] [Indexed: 12/24/2022]
Abstract
In birds, biological clock function pervades all aspects of biology, controlling daily changes in sleep: wake, visual function, song, migratory patterns and orientation, as well as seasonal patterns of reproduction, song and migration. The molecular bases for circadian clocks are highly conserved, and it is likely the avian molecular mechanisms are similar to those expressed in mammals, including humans. The central pacemakers in the avian pineal gland, retinae and SCN dynamically interact to maintain stable phase relationships and then influence downstream rhythms through entrainment of peripheral oscillators in the brain controlling behavior and peripheral tissues. Birds represent an excellent model for the role played by biological clocks in human neurobiology; unlike most rodent models, they are diurnal, they exhibit cognitively complex social interactions, and their circadian clocks are more sensitive to the hormone melatonin than are those of nocturnal rodents.
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Affiliation(s)
- Vincent M Cassone
- Department of Biology, University of Kentucky, Lexington, KY 40506, United States.
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28
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Lilienthal H, Heikkinen P, Andersson PL, Viluksela M. Sexually dimorphic behavior after developmental exposure to characterize endocrine-mediated effects of different non-dioxin-like PCBs in rats. Toxicology 2013; 311:52-60. [DOI: 10.1016/j.tox.2013.01.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 01/15/2013] [Accepted: 01/30/2013] [Indexed: 12/15/2022]
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Bardet SM, Mouriec K, Balthazart J. Birth of neural progenitors during the embryonic period of sexual differentiation in the Japanese quail brain. J Comp Neurol 2013; 520:4226-53. [PMID: 22628012 DOI: 10.1002/cne.23153] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Several brain areas in the diencephalon are involved in the activation and expression of sexual behavior, including in quail the medial preoptic nucleus (POM). However, the ontogeny of these diencephalic brain nuclei has not to this date been examined in detail. We investigated the ontogeny of POM and other steroid-sensitive brain regions by injecting quail eggs with 5-bromo-2-deoxyuridine (BrdU) at various stages between embryonic day (E)3 and E16 and killing animals at postnatal (PN) days 3 or 56. In the POM, large numbers of BrdU-positive cells were observed in subjects injected from E3-E10, the numbers of these cells was intermediate in birds injected on E12, and most cells were postmitotic in both sexes on E14-E16. Injections on E3-E4 labeled large numbers of Hu-positive cells in POM. In contrast, injections performed at a later stage labeled cells that do not express aromatase nor neuronal markers such as Hu or NeuN in the POM and other steroid-sensitive nuclei and thus do not have a neuronal phenotype in these locations, contrary to what is observed in the telencephalon and cerebellum. No evidence could also be collected to demonstrate that these cells have a glial nature. Converging data, including the facts that these cells divide in the brain mantle and express proliferating cell nuclear antigen (PCNA), a cell cycling marker, indicate that cells labeled by BrdU during the second half of embryonic life are slow-cycling progenitors born and residing in the brain mantle. Future research should now identify their functional significance.
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Affiliation(s)
- Sylvia M Bardet
- GIGA Neurosciences, Research Group in Behavioral Neuroendocrinology, University of Liège, Liège, Belgium
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Apfelbeck B, Mortega K, Kiefer S, Kipper S, Vellema M, Villavicencio CP, Gahr M, Goymann W. Associated and disassociated patterns in hormones, song, behavior and brain receptor expression between life-cycle stages in male black redstarts, Phoenicurus ochruros. Gen Comp Endocrinol 2013; 184:93-102. [PMID: 23337030 DOI: 10.1016/j.ygcen.2012.11.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 10/24/2012] [Accepted: 11/22/2012] [Indexed: 12/22/2022]
Abstract
Testosterone has been suggested to be involved in the regulation of male territorial behavior. For example, seasonal peaks in testosterone typically coincide with periods of intense competition between males for territories and mating partners. However, some species also express territorial behavior outside a breeding context when testosterone levels are low and, thus, the degree to which testosterone facilitates territorial behavior in these species is not well understood. We studied territorial behavior and its neuroendocrine correlates in male black redstarts. Black redstarts defend territories in spring during the breeding period, but also in the fall outside a reproductive context when testosterone levels are low. In the present study we assessed if song output and structure remain stable across life-cycle stages. Furthermore, we assessed if brain anatomy may give insight into the role of testosterone in the regulation of territorial behavior in black redstarts. We found that males sang spontaneously at a high rate during the nonbreeding period when testosterone levels were low; however the trill-like components of spontaneously produced song contained less repetitive elements during nonbreeding than during breeding. This higher number of repetitive elements in trills did not, however, correlate with a larger song control nucleus HVC during breeding. However, males expressed more aromatase mRNA in the preoptic area - a brain nucleus important for sexual and aggressive behavior - during breeding than during nonbreeding. In combination with our previous studies on black redstarts our results suggest that territorial behavior in this species only partly depends on sex steroids: spontaneous song output, seasonal variation in trills and non-vocal territorial behavior in response to a simulated territorial intruder seem to be independent of sex steroids. However, context-dependent song during breeding may be facilitated by testosterone - potentially by conversion of testosterone to estradiol in the preoptic area.
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Affiliation(s)
- Beate Apfelbeck
- Abteilung für Verhaltensneurobiologie, Max-Planck-Institut für Ornithologie, Seewiesen, Germany.
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Distribution and characterization of doublecortin-expressing cells and fibers in the brain of the adult pigeon (Columba livia). J Chem Neuroanat 2013; 47:57-70. [DOI: 10.1016/j.jchemneu.2012.10.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 10/29/2012] [Accepted: 10/29/2012] [Indexed: 01/03/2023]
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Ottem EN, Bailey DJ, Jordan CL, Breedlove SM. With a little help from my friends: androgens tap BDNF signaling pathways to alter neural circuits. Neuroscience 2012; 239:124-38. [PMID: 23262234 DOI: 10.1016/j.neuroscience.2012.12.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 12/03/2012] [Accepted: 12/05/2012] [Indexed: 12/20/2022]
Abstract
Gonadal androgens are critical for the development and maintenance of sexually dimorphic regions of the male nervous system, which is critical for male-specific behavior and physiological functioning. In rodents, the motoneurons of the spinal nucleus of the bulbocavernosus (SNB) provide a useful example of a neural system dependent on androgen. Unless rescued by perinatal androgens, the SNB motoneurons will undergo apoptotic cell death. In adulthood, SNB motoneurons remain dependent on androgen, as castration leads to somal atrophy and dendritic retraction. In a second vertebrate model, the zebra finch, androgens are critical for the development of several brain nuclei involved in song production in males. Androgen deprivation during a critical period during postnatal development disrupts song acquisition and dimorphic size-associated nuclei. Mechanisms by which androgens exert masculinizing effects in each model system remain elusive. Recent studies suggest that brain-derived neurotrophic factor (BDNF) may play a role in androgen-dependent masculinization and maintenance of both SNB motoneurons and song nuclei of birds. This review aims to summarize studies demonstrating that BDNF signaling via its tyrosine receptor kinase (TrkB) receptor may work cooperatively with androgens to maintain somal and dendritic morphology of SNB motoneurons. We further describe studies that suggest the cellular origin of BDNF is of particular importance in androgen-dependent regulation of SNB motoneurons. We review evidence that androgens and BDNF may synergistically influence song development and plasticity in bird species. Finally, we provide hypothetical models of mechanisms that may underlie androgen- and BDNF-dependent signaling pathways.
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Affiliation(s)
- E N Ottem
- Department of Biology, Northern Michigan University, Marquette, MI 49855, USA.
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Apfelbeck B, Kiefer S, Mortega KG, Goymann W, Kipper S. Testosterone affects song modulation during simulated territorial intrusions in male black redstarts (Phoenicurus ochruros). PLoS One 2012; 7:e52009. [PMID: 23284852 PMCID: PMC3524101 DOI: 10.1371/journal.pone.0052009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 11/07/2012] [Indexed: 12/26/2022] Open
Abstract
Although it has been suggested that testosterone plays an important role in resource allocation for competitive behavior, details of the interplay between testosterone, territorial aggression and signal plasticity are largely unknown. Therefore, we investigated if testosterone acts specifically on signals that communicate the motivation or ability of individuals to engage in competitive situations in a natural context. We studied the black redstart, a territorial songbird species, during two different life-cycle stages, the early breeding phase in spring and the non-breeding phase in fall. Male territory holders were implanted with the androgen receptor blocker flutamide (Flut) and the aromatase inhibitor letrozole (Let) to inhibit the action of testosterone and its estrogenic metabolites. Controls received a placebo treatment. Three days after implantation birds were challenged with a simulated territorial intrusion (STI). Song was recorded before, during and after the challenge. In spring, both treatment groups increased the number of elements sung in parts of their song in response to the STI. However, Flut/Let-implanted males reacted to the STI with a decreased maximum acoustic frequency of one song part, while placebo-implanted males did not. Instead, placebo-implanted males sang the atonal part of their song with a broader frequency range. Furthermore, placebo-, but not Flut/Let-implanted males, sang shorter songs with shorter pauses between parts in the STIs. During simulated intrusions in fall, when testosterone levels are naturally low in this species, males of both treatment groups sang similar to Flut/Let-implanted males during breeding. The results suggest that song sung during a territorial encounter is of higher competitive value than song sung in an undisturbed situation and may, therefore, convey information about the motivation or quality of the territory holder. We conclude that testosterone facilitates context-dependent changes in song structures that may be honest signals of male quality in black redstarts.
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Affiliation(s)
- Beate Apfelbeck
- Abteilung für Verhaltensneurobiologie, Max-Planck-Institut für Ornithologie, Seewiesen, Germany.
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Cell proliferation pattern in adult zebrafish forebrain is sexually dimorphic. Neuroscience 2012; 226:367-81. [DOI: 10.1016/j.neuroscience.2012.09.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 09/07/2012] [Accepted: 09/07/2012] [Indexed: 12/31/2022]
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Xu X, Coats JK, Yang CF, Wang A, Ahmed OM, Alvarado M, Izumi T, Shah NM. Modular genetic control of sexually dimorphic behaviors. Cell 2012; 148:596-607. [PMID: 22304924 DOI: 10.1016/j.cell.2011.12.018] [Citation(s) in RCA: 191] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 09/22/2011] [Accepted: 12/16/2011] [Indexed: 12/18/2022]
Abstract
Sex hormones such as estrogen and testosterone are essential for sexually dimorphic behaviors in vertebrates. However, the hormone-activated molecular mechanisms that control the development and function of the underlying neural circuits remain poorly defined. We have identified numerous sexually dimorphic gene expression patterns in the adult mouse hypothalamus and amygdala. We find that adult sex hormones regulate these expression patterns in a sex-specific, regionally restricted manner, suggesting that these genes regulate sex typical behaviors. Indeed, we find that mice with targeted disruptions of each of four of these genes (Brs3, Cckar, Irs4, Sytl4) exhibit extremely specific deficits in sex specific behaviors, with single genes controlling the pattern or extent of male sexual behavior, male aggression, maternal behavior, or female sexual behavior. Taken together, our findings demonstrate that various components of sexually dimorphic behaviors are governed by separable genetic programs.
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Affiliation(s)
- Xiaohong Xu
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA
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Adult neuron addition to the zebra finch song motor pathway correlates with the rate and extent of recovery from botox-induced paralysis of the vocal muscles. J Neurosci 2012; 31:16958-68. [PMID: 22114266 DOI: 10.1523/jneurosci.2971-11.2011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In adult songbirds, neurons are continually incorporated into the telencephalic nucleus HVC (used as a proper name), a premotor region necessary for the production of learned vocalizations. Previous studies have demonstrated that neuron addition to HVC is highest when song is most variable: in juveniles during song learning, in seasonally singing adults during peaks in plasticity that precede the production of new song components, or during seasonal reestablishment of a previously learned song. These findings suggest that neuron addition provides motor flexibility for the transition from a variable song to a target song. Here we test the association between the quality of song structure and HVC neuron addition by experimentally manipulating syringeal muscle control with Botox, which produces a transient partial paralysis. We show that the quality of song structure covaries with new neuron addition to HVC. Both the magnitude of song distortion and the rate of song recovery after syringeal Botox injections were correlated with the number of new neurons incorporated into HVC. We suggest that the quality of song structure is either a cause or consequence of the number of new neurons added to HVC. Birds with naturally high rates of neuron addition may have had the greatest success in recovering song. Alternatively, or in addition, new neuron survival in the song motor pathway may be regulated by the quality of song-generated feedback as song regains its original stereotyped structure. Present results are the first to show a relationship between peripheral muscle control and adult neuron addition to cortical premotor circuits.
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Södersten P, Bergh C, Zandian M, Ioakimidis I. Obesity and the brain. Med Hypotheses 2011; 77:371-3. [DOI: 10.1016/j.mehy.2011.05.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Accepted: 05/15/2011] [Indexed: 12/27/2022]
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Pfannkuche KA, Gahr M, Weites IM, Riedstra B, Wolf C, Groothuis TGG. Examining a pathway for hormone mediated maternal effects--yolk testosterone affects androgen receptor expression and endogenous testosterone production in young chicks (Gallus gallus domesticus). Gen Comp Endocrinol 2011; 172:487-93. [PMID: 21536043 DOI: 10.1016/j.ygcen.2011.04.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 03/29/2011] [Accepted: 04/15/2011] [Indexed: 11/17/2022]
Abstract
In vertebrates maternal androgens can substantially influence developing offspring, inducing both short and long term changes in physiology and behavior, including androgen sensitive traits. However, how the effects of maternal hormones are mediated remains unknown. Two possible pathways are that maternal androgens affect parts of the hypothalamus-pituitary-gonadal axis (HPG axis) or the sensitivity to androgens by affecting androgen receptor (AR) densities within the brain. To investigate both pathways, testosterone within the physiological range or vehicle only was injected into the egg yolk of unincubated chicken eggs and AR mRNA expression in different brain nuclei as well as plasma testosterone levels were measured in two week old male and female chicks that had hatched from these eggs. Our results showed a significant sex difference in plasma testosterone levels with males showing higher levels than females. Furthermore, AR mRNA expression as well as plasma testosterone levels were significantly lower in chicks hatched from testosterone treated eggs. These results suggest a compensatory mechanism for avoiding potential detrimental effects of high testosterone levels.
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Affiliation(s)
- K A Pfannkuche
- Behavioral Biology Research Group, Center for Behavior and Cognitive Studies, University of Groningen, Groningen, The Netherlands.
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