1
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LaDage LD. Seasonal variation in gonadal hormones, spatial cognition, and hippocampal attributes: More questions than answers. Horm Behav 2022; 141:105151. [PMID: 35299119 DOI: 10.1016/j.yhbeh.2022.105151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 02/25/2022] [Accepted: 02/27/2022] [Indexed: 11/04/2022]
Abstract
A large body of research has been dedicated to understanding the factors that modulate spatial cognition and attributes of the hippocampus, a highly plastic brain region that underlies spatial processing abilities. Variation in gonadal hormones impacts spatial memory and hippocampal attributes in vertebrates, although the direction of the effect has not been entirely consistent. To add complexity, individuals in the field must optimize fitness by coordinating activities with the appropriate environmental cues, and many of these behaviors are correlated tightly with seasonal variation in gonadal hormone release. As such, it remains unclear if the relationship among systemic gonadal hormones, spatial cognition, and the hippocampus also exhibits seasonal variation. This review presents an overview of the relationship among gonadal hormones, the hippocampus, and spatial cognition, and how the seasonal release of gonadal hormones correlates with seasonal variation in spatial cognition and hippocampal attributes. Additionally, this review presents other neuroendocrine mechanisms that may be involved in modulating the relationship among seasonality, gonadal hormone release, and the hippocampus and spatial cognition, including seasonal rhythms of steroid hormone binding globulins, neurosteroids, sex steroid hormone receptor expression, and hormone interactions. Here, endocrinology, ecology, and behavioral neuroscience are brought together to present an overview of the research demonstrating the mechanistic effects of systemic gonadal hormones on spatial cognition and the hippocampus, while, at a functional level, superimposing seasonal effects to examine ecologically-relevant circannual changes in gonadal hormones and spatial behaviors.
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Affiliation(s)
- Lara D LaDage
- Penn State Altoona, Division of Mathematics & Natural Sciences, 3000 Ivyside Dr., Altoona, PA 16601, USA.
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2
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Petric R, Kalcounis-Rueppell MC, Marler CA. Testosterone pulses paired with a location induce a place preference to the nest of a monogamous mouse under field conditions. eLife 2022; 11:65820. [PMID: 35352677 PMCID: PMC9023057 DOI: 10.7554/elife.65820] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/29/2022] [Indexed: 11/13/2022] Open
Abstract
Changing social environments such as the birth of young or aggressive encounters present a need to adjust behavior. Previous research examined how long-term changes in steroid hormones mediate these adjustments. We tested the novel concept that the rewarding effects of transient testosterone pulses (T-pulses) in males after social encounters alters their spatial distribution on a territory. In free-living monogamous California mice (Peromyscus californicus), males administered three T-injections at the nest spent more time at the nest than males treated with placebo injections. This mimics T-induced place preferences in the laboratory. Female mates of T-treated males spent less time at the nest but the pair produced more vocalizations and call types than controls. Traditionally, transient T-changes were thought to have transient behavioral effects. Our work demonstrates that in the wild, when T-pulses occur in a salient context such as a territory, the behavioral effects last days after T-levels return to baseline.
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Affiliation(s)
- Radmila Petric
- Institute for the Environment, University of North Carolina at Chapel Hill, Chapel Hill, United States
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3
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Inbar T, Davis R, Bergan JF. A sex-specific feedback projection from aromatase-expressing neurons in the medial amygdala to the accessory olfactory bulb. J Comp Neurol 2022; 530:648-655. [PMID: 34415057 PMCID: PMC8716422 DOI: 10.1002/cne.25236] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/09/2021] [Accepted: 08/17/2021] [Indexed: 02/03/2023]
Abstract
The accessory olfactory bulb (AOB) plays a critical role in classifying pheromonal signals. Here we identify two previously undescribed sources of aromatase signaling in the AOB: (1) a population of aromatase-expressing neurons in the AOB itself; (2) a tract of aromatase-expressing axons which originate in the ventral medial amygdala (MEA) and terminate in the AOB. Using a retrograde tracer in conjunction with a transgenic strategy to label aromatase-expressing neurons throughout the brain, we found that a single contiguous population of neurons in the ventral MEA provides the only significant feedback by aromatase-expressing neurons to the AOB. This population expresses the estrogen receptor alpha (ERα) and displayed anatomical sex differences in the number of neurons (higher in male mice) and the size of cell bodies (larger in females). Given the previously established relationship between aromatase expression, estrogen signaling, and the function of sexually dimorphic circuits, we suggest that this feedback population is well-positioned to provide neuroendocrine feedback to modulate sensory processing of social stimuli in the AOB.
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Affiliation(s)
- Tal Inbar
- Neuroscience and Behavior Graduate Program, University of Massachusetts at Amherst
| | - Rachel Davis
- Department of Psychological and Brain Sciences, University of Massachusetts at Amherst
| | - Joseph F. Bergan
- Neuroscience and Behavior Graduate Program, University of Massachusetts at Amherst,Department of Psychological and Brain Sciences, University of Massachusetts at Amherst
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4
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Mechanisms of multimodality: androgenic hormones and adaptive flexibility in multimodal displays. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2021.08.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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5
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Balthazart J. Membrane-initiated actions of sex steroids and reproductive behavior: A historical account. Mol Cell Endocrinol 2021; 538:111463. [PMID: 34582978 DOI: 10.1016/j.mce.2021.111463] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 01/25/2023]
Abstract
It was assumed for a long time that sex steroids are activating reproductive behaviors by the same mechanisms that produce their morphological and physiological effects in the periphery. However during the last few decades an increasing number of examples were identified where behavioral effects of steroids were just too fast to be mediated via changes in DNA transcription. This progressively forced behavioral neuroendocrinologists to recognize that part of the effects of steroids on behavior are mediated by membrane-initiated events. In this review we present a selection of these early data that changed the conceptual landscape and we provide a summary the different types of membrane-associated receptors (estrogens, androgens and progestagens receptors) that are playing the most important role in the control of reproductive behaviors. Then we finally describe in more detail three separate behavioral systems in which membrane-initiated events have clearly been established to contribute to behavior control.
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6
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Chagnaud BP, Perelmuter JT, Forlano PM, Bass AH. Gap junction-mediated glycinergic inhibition ensures precise temporal patterning in vocal behavior. eLife 2021; 10:e59390. [PMID: 33721553 PMCID: PMC7963477 DOI: 10.7554/elife.59390] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 02/28/2021] [Indexed: 01/30/2023] Open
Abstract
Precise neuronal firing is especially important for behaviors highly dependent on the correct sequencing and timing of muscle activity patterns, such as acoustic signaling. Acoustic signaling is an important communication modality for vertebrates, including many teleost fishes. Toadfishes are well known to exhibit high temporal fidelity in synchronous motoneuron firing within a hindbrain network directly determining the temporal structure of natural calls. Here, we investigated how these motoneurons maintain synchronous activation. We show that pronounced temporal precision in population-level motoneuronal firing depends on gap junction-mediated, glycinergic inhibition that generates a period of reduced probability of motoneuron activation. Super-resolution microscopy confirms glycinergic release sites formed by a subset of adjacent premotoneurons contacting motoneuron somata and dendrites. In aggregate, the evidence supports the hypothesis that gap junction-mediated, glycinergic inhibition provides a timing mechanism for achieving synchrony and temporal precision in the millisecond range for rapid modulation of acoustic waveforms.
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Affiliation(s)
| | | | - Paul M Forlano
- Department of Biology, Brooklyn College, City University of New YorkBrooklyn, NYUnited States
- Subprograms in Behavioral and Cognitive Neuroscience, Neuroscience, and Ecology, Evolutionary Biology and Behavior, The Graduate Center, City University of New YorkNew York, NYUnited States
| | - Andrew H Bass
- Department of Neurobiology and Behavior, Cornell UniversityIthaca, NYUnited States
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7
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Leary CJ, Baugh AT. Glucocorticoids, male sexual signals, and mate choice by females: Implications for sexual selection. Gen Comp Endocrinol 2020; 288:113354. [PMID: 31830474 DOI: 10.1016/j.ygcen.2019.113354] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 12/01/2019] [Accepted: 12/06/2019] [Indexed: 12/29/2022]
Abstract
We review work relating glucocorticoids (GCs), male sexual signals, and mate choice by females to understand the potential for GCs to modulate the expression of sexually selected traits and how sexual selection potentially feeds back on GC regulation. Our review reveals that the relationship between GC concentrations and the quality of male sexual traits is mixed, regardless of whether studies focused on structural traits (e.g., coloration) or behavioral traits (e.g., vocalizations) or were examined in developmental or activational frameworks. In contrast, the few mate choice experiments that have been done consistently show that females prefer males with low GCs, suggesting that mate choice by females favors males that maintain low levels of GCs. We point out, however, that just as sexual selection can drive the evolution of diverse reproductive strategies, it may also promote diversity in GC regulation. We then shift the focus to females where we highlight evidence indicating that stressors or high GCs can dampen female sexual proceptivity and the strength of preferences for male courtship signals. Hence, even in cases where GCs are tightly coupled with male sexual signals, the strength of sexual selection on aspects of GC physiology can vary depending on the endocrine status of females. Studies examining how GCs relate to sexual selection may shed light on how variation in stress physiology, sexual signals, and mate choice are maintained in natural populations and may be important in understanding context-dependent relationships between GC regulation and fitness.
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Affiliation(s)
- Christopher J Leary
- Department of Biology, University of Mississippi, PO Box 1848, University, MS 38677, USA.
| | - Alexander T Baugh
- Department of Biology, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA
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8
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Boonstra R, Dušek A, Flynn RW. DHEA and territoriality during the nonbreeding season in male American martens (Martes americana). J Mammal 2018. [DOI: 10.1093/jmammal/gyy067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Affiliation(s)
- Rudy Boonstra
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Adam Dušek
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto, Toronto, Ontario, Canada
- Department of Ethology, Institute of Animal Science, Praha, Czech Republic
| | - Rodney W Flynn
- Alaska Department of Fish and Game, Division of Wildlife, Juneau, AK, USA
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9
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Balthazart J, Choleris E, Remage-Healey L. Steroids and the brain: 50years of research, conceptual shifts and the ascent of non-classical and membrane-initiated actions. Horm Behav 2018; 99:1-8. [PMID: 29305886 PMCID: PMC5880709 DOI: 10.1016/j.yhbeh.2018.01.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 12/30/2017] [Accepted: 01/02/2018] [Indexed: 11/22/2022]
Abstract
This brief commentary reviews key steps in the history of steroid endocrinology that have resulted in important conceptual shifts. Our understanding of the "Fast Effects of Steroids" now reflect substantial progress, including the major concept that steroids act rapidly on a variety of physiological and behavioral responses, via mechanisms that are too fast to be fully accounted for by classical receptor-dependent regulation of gene transcription. Several so-called 'non-classical' mechanisms have been identified and include binding to membrane receptors and regulating non genomic signaling cascades. We survey the discovery of steroids, the initial characterization of their intracellular receptors, key progress in the understanding of the genomic effects of steroids and then the progressive discovery of the rapid non-classical and membrane-initiated actions of steroids. Foundational discoveries about brain steroid synthesis in neural processes and terminals has converged with emerging evidence for the rapid actions of steroids on brain and behavior. Had the rapid effects of steroids in the central nervous system been discovered first, these molecules would likely now be considered as a class of neurotransmitter.
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Affiliation(s)
| | - Elena Choleris
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Luke Remage-Healey
- Center for Neuroendocrine Studies, University of Massachusetts Amherst, Amherst, MA 01003, USA
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10
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Boonstra R, Dušek A, Lane JE, Boutin S. When the ball is in the female's court: How the scramble-competition mating system of the North American red squirrel has shaped male physiology and testosterone dynamics. Gen Comp Endocrinol 2017. [PMID: 28648995 DOI: 10.1016/j.ygcen.2017.06.016] [Citation(s) in RCA: 5] [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] [Indexed: 10/19/2022]
Abstract
Male reproductive success in most mammals is determined by their success in direct inter-male competition through aggression and conflict, resulting in female-defense mating systems being predominant. This is linked to male testosterone levels and its dynamics. However, in certain environments, a scramble-competition mating system has evolved, where female reproductive behavior takes precedence and male testosterone dynamics are unlikely to be related to inter-male competition. We studied the North American red squirrel (Tamiasciurus hudsonicus), a species with a well-established scramble-competition system. Using an ACTH hormonal challenge protocol as a proxy for competitive interactions, we compared the testosterone dynamics in breeding males in late winter with that in nonbreeding males in late spring in the Yukon. To gain an integrated picture of their physiological state, we also assessed changes in their stress response, body mass, energy mobilization, and indices of immune function. Testosterone levels at the base bleed were high in breeding males (2.72ng/mL) and virtually absent in non-breeding males (0.04ng/mL). Breeding males were in better condition (heavier body mass, higher hematocrit, and higher erythrocytes), had higher indices of immune function (neutrophil:lymphocyte ratio), but a similar ability to mobilize energy (glucose) compared with non-breeding males. Though total cortisol was higher in non-breeding males, free cortisol was twice as high in breeding males as their corticosteroid binding globulin levels were half as high. In response to the ACTH challenge, testosterone levels in breeding males declined 49% over the first hour and increased 36% over the next hour; in non-breeding males levels showed no change. Free cortisol increased only modestly (26% in breeding males; 23% in non-breeding males). Glucose levels changed similarly in breeding and nonbreeding males, declining for the first 30min and then increasing for the next 60min. Thus, testosterone and components of the stress axis function in a profoundly different manner in male red squirrels than in males of mammals with female-defense mating systems. There are four probable interrelated reasons for these adaptations in male red squirrels: the marginal benefits of each mating, the constraints of mate searching away from their own resource-based territories, energy mobilization in a harsh environment, and a long life span.
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Affiliation(s)
- Rudy Boonstra
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada.
| | - Adam Dušek
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada; Department of Ethology, Institute of Animal Science, Praha CZ-104 00, Czech Republic
| | - Jeffrey E Lane
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada; Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
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11
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Modesto T, Freitas AMMS, Canario AVM. Steroidogenesis by testis and accessory glands of the Lusitanian toadfish, Halobatrachus didactylus, during reproductive season. Gen Comp Endocrinol 2015; 223:120-8. [PMID: 26435361 DOI: 10.1016/j.ygcen.2015.09.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 01/27/2015] [Accepted: 09/04/2015] [Indexed: 11/22/2022]
Abstract
In teleost fish sex steroids are essential for gonadal function and have marked effects in reproductive and agonistic behavior and in the expression of secondary sexual characteristics. The Lusitanian toadfish, Halobatrachus didactylus, has two male morphotypes: type I males are territorial nest-holders and have large accessory glands while type II males are smaller, have a relatively large testis and small accessory glands. In the present study, the steroidogenic activity of the testis and accessory testicular glands of the Lusitanian toadfish were examined in vitro as well as their presence in urine. The testis of type I males produced 11-ketotestosterone (11KT) and 11β-hydroxy-4-androstene-3,17-dione (11βA) from tritiated 17-hydroxyprogesterone, while those of type II males produced testosterone (T) and 11β,17β-dihydroxy-4-andosten-3-one (11βT), but not 11KT. Additionally, the testis and accessory glands of both morphs produced mostly 5β,3α-reduced and 17,20α-hydroxylated metabolites. Type I, but not of type II, males synthesised 5β-reduced androgens in their accessory glands. The presence of 11βA exclusively in the urine of type I males during reproductive season suggests an association with maintenance of secondary sexual characteristics and behavior in this morph. The urine of both types of males contained two 5α-androstane and 5β-pregnane glucuronides. Among the latter steroids, those that are 17,21-dihydroxylated are potentially metabolites from cortisol and were found only in type I males during the spawning season. The diversity of metabolites produced by the testis and accessory glands and the presence of some in urine is suggestive of a potential role in chemical communication and reproductive behavior.
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Affiliation(s)
- Teresa Modesto
- CCMAR - Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
| | - Ana M M S Freitas
- Centro de Estudos e Desenvolvimento em Saúde, Universidade do Algarve, Av. Dr. Adelino da Palma Carlos, 8000-510 Faro, Portugal
| | - Adelino V M Canario
- CCMAR - Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
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12
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Amorim MCP, Conti C, Modesto T, Gonçalves A, Fonseca PJ. Agonistic sounds signal male quality in the Lusitanian toadfish. Physiol Behav 2015; 149:192-8. [PMID: 26048302 DOI: 10.1016/j.physbeh.2015.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 05/27/2015] [Accepted: 06/01/2015] [Indexed: 11/17/2022]
Abstract
Acoustic communication during agonistic behaviour is widespread in fishes. Yet, compared to other taxa, little is known on the information content of fish agonistic calls and their effect on territorial defence. Lusitanian toadfish males (Halobatrachus didactylus) are highly territorial during the breeding season and use sounds (boatwhistles, BW) to defend nests from intruders. BW present most energy in either the fundamental frequency, set by the contraction rate of the sonic muscles attached to the swimbladder, or in the harmonics, which are multiples of the fundamental frequency. Here we investigated if temporal and spectral features of BW produced during territorial defence reflect aspects of male quality that may be important in resolving disputes. We found that higher mean pulse period (i.e. lower fundamental frequency) reflected higher levels of 11-ketotestosterone (11KT), the main teleost androgen which, in turn, was significantly related with male condition (relative body mass and glycogen content). BW dominant harmonic mean and variability decreased with sonic muscle lipid content. We found no association between BW duration and male quality. Taken together, these results suggest that the spectral content of fish agonistic sounds may signal male features that are key in fight outcome.
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Affiliation(s)
- M Clara P Amorim
- MARE - Marine and Environmental Sciences Centre, ISPA - Instituto Universitário, Lisbon, Portugal.
| | - Carlotta Conti
- MARE - Marine and Environmental Sciences Centre, ISPA - Instituto Universitário, Lisbon, Portugal.
| | - Teresa Modesto
- Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8000-810 Faro, Portugal.
| | - Amparo Gonçalves
- Division of Aquaculture and Upgrading, Portuguese Institute for the Sea and Atmosphere, I.P. (IPMA, I.P.), Lisbon, Portugal.
| | - Paulo J Fonseca
- Departamento de Biologia Animal and cE3c - Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal.
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13
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Bergan JF. Neural Computation and Neuromodulation Underlying Social Behavior. Integr Comp Biol 2015; 55:268-80. [PMID: 26089436 DOI: 10.1093/icb/icv061] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Social behaviors are as diverse as the animals that employ them, with some behaviors, like affiliation and aggression, expressed in nearly all social species. Whether discussing a "family" of beavers or a "murder" of crows, the elaborate language we use to describe social animals immediately hints at patterns of behavior typical of each species. Neuroscience has now revealed a core network of regions of the brain that are essential for the production of social behavior. Like the behaviors themselves, neuromodulation and hormonal changes regulate the underlying neural circuits on timescales ranging from momentary events to an animal's lifetime. Dynamic and heavily interconnected social circuits provide a distinct challenge for developing a mechanistic understanding of social behavior. However, advances in neuroscience continue to generate an explanation of social behavior based on the electrical activity and synaptic connections of neurons embedded in defined neural circuits.
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Affiliation(s)
- Joseph F Bergan
- Department of Psychology and Brain Sciences, University of Massachusetts, Amherst, MA 01003, USA
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14
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Leininger EC, Kitayama K, Kelley DB. Species-specific loss of sexual dimorphism in vocal effectors accompanies vocal simplification in African clawed frogs (Xenopus). ACTA ACUST UNITED AC 2015; 218:849-57. [PMID: 25788725 DOI: 10.1242/jeb.115048] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phylogenetic studies can reveal patterns of evolutionary change, including the gain or loss of elaborate courtship traits in males. Male African clawed frogs generally produce complex and rapid courtship vocalizations, whereas female calls are simple and slow. In a few species, however, male vocalizations are also simple and slow, suggesting loss of male-typical traits. Here, we explore features of the male vocal organ that could contribute to loss in two species with simple, slow male calls. In Xenopus boumbaensis, laryngeal morphology is more robust in males than in females. Larynges are larger, have a more complex cartilaginous morphology and contain more muscle fibers. Laryngeal muscle fibers are exclusively fast-twitch in males but are both fast- and slow-twitch in females. The laryngeal electromyogram, a measure of neuromuscular synaptic strength, shows greater potentiation in males than in females. Male-specific physiological features are shared with X. laevis, as well as with a species of the sister clade, Silurana tropicalis, and thus are likely ancestral. In X. borealis, certain aspects of laryngeal morphology and physiology are sexually monomorphic rather than dimorphic. In both sexes, laryngeal muscle fibers are of mixed-twitch type, which limits the production of muscle contractions at rapid intervals. Muscle activity potentiation and discrete tension transients resemble female rather than male X. boumbaensis. The de-masculinization of these laryngeal features suggests an alteration in sensitivity to the gonadal hormones that are known to control the sexual differentiation of the larynx in other Xenopus and Silurana species.
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Affiliation(s)
- Elizabeth C Leininger
- Program in Neurobiology and Behavior, Columbia University, New York, NY 10027, USA Department of Biological Sciences, Columbia University, New York, NY 10027, USA Biology Department, St Mary's College of Maryland, St Mary's City MD 20868, USA
| | - Ken Kitayama
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Darcy B Kelley
- Program in Neurobiology and Behavior, Columbia University, New York, NY 10027, USA Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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15
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Maruska KP. Social Transitions Cause Rapid Behavioral and Neuroendocrine Changes. Integr Comp Biol 2015; 55:294-306. [PMID: 26037297 DOI: 10.1093/icb/icv057] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
In species that form dominance hierarchies, there are often opportunities for low-ranking individuals to challenge high-ranking ones, resulting in a rise or fall in social rank. How does an animal rapidly detect, process, and then respond to these social transitions? This article explores and summarizes how these social transitions can rapidly (within 24 h) impact an individual's behavior, physiology, and brain, using the African cichlid fish, Astatotilapia burtoni, as a model. Male A. burtoni form hierarchies in which a few brightly-colored dominant males defend territories and spawn with females, while the remaining males are subordinate, more drab-colored, do not hold a territory, and have minimal opportunities for reproduction. These social phenotypes are plastic and reversible, meaning that individual males may switch between dominant and subordinate status multiple times within a lifetime. When the social environment is manipulated to create males that either ascend (subordinate to dominant) or descend (dominant to subordinate) in rank, there are rapid changes in behavior, circulating hormones, and levels of gene expression in the brain that reflect the direction of transition. For example, within minutes, males ascending in status show bright coloration, a distinct eye-bar, increased dominance behaviors, activation of brain nuclei in the social behavior network, and higher levels of sex steroids in the plasma. Ascending males also show rapid changes in levels of neuropeptide and steroid receptors in the brain, as well as in the pituitary and testes. To further examine hormone-behavior relationships in this species during rapid social ascent, the present study also measured levels of testosterone, 11-ketotestosterone, estradiol, progestins, and cortisol in the plasma during the first week of social ascent and tested for correlations with behavior. Plasma levels of all steroids were rapidly increased at 30 min after social ascent, but were not correlated with behavior during the initial rise in rank, suggesting that behavior is dissociated from endocrine status. These changes during social ascent are then compared with our current knowledge about males descending in rank, who rapidly show faded coloration, decreased dominance behaviors, increased subordinate behaviors, and higher circulating levels of cortisol. Collectively, this work highlights how the perception of similar social cues that are opposite in value are rapidly translated into adaptive behavioral and neuroendocrine changes that promote survival and reproductive fitness. Finally, future directions are proposed to better understand the mechanisms that govern these rapid changes in social position.
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Affiliation(s)
- Karen P Maruska
- Department of Biological Sciences, Louisiana State University, 202 Life Sciences Bldg, Baton Rouge, LA 70803, USA
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16
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Feng NY, Fergus DJ, Bass AH. Neural transcriptome reveals molecular mechanisms for temporal control of vocalization across multiple timescales. BMC Genomics 2015; 16:408. [PMID: 26014649 PMCID: PMC4446069 DOI: 10.1186/s12864-015-1577-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/24/2015] [Indexed: 12/13/2022] Open
Abstract
Background Vocalization is a prominent social behavior among vertebrates, including in the midshipman fish, an established model for elucidating the neural basis of acoustic communication. Courtship vocalizations produced by territorial males are essential for reproductive success, vary over daily and seasonal cycles, and last up to hours per call. Vocalizations rely upon extreme synchrony and millisecond precision in the firing of a homogeneous population of motoneurons, the vocal motor nucleus (VMN). Although studies have identified neural mechanisms driving rapid, precise, and stable neuronal firing over long periods of calling, little is known about underlying genetic/molecular mechanisms. Results We used RNA sequencing-based transcriptome analyses to compare patterns of gene expression in VMN to the surrounding hindbrain across three daily and seasonal time points of high and low sound production to identify candidate genes that underlie VMN’s intrinsic and network neuronal properties. Results from gene ontology enrichment, enzyme pathway mapping, and gene category-wide expression levels highlighted the importance of cellular respiration in VMN function, consistent with the high energetic demands of sustained vocal behavior. Functionally important candidate genes upregulated in the VMN, including at time points corresponding to high natural vocal activity, encode ion channels and neurotransmitter receptors, hormone receptors and biosynthetic enzymes, neuromodulators, aerobic respiration enzymes, and antioxidants. Quantitative PCR and RNA-seq expression levels for 28 genes were significantly correlated. Many candidate gene products regulate mechanisms of neuronal excitability, including those previously identified in VMN motoneurons, as well as novel ones that remain to be investigated. Supporting evidence from previous studies in midshipman strongly validate the value of transcriptomic analyses for linking genes to neural characters that drive behavior. Conclusions Transcriptome analyses highlighted a suite of molecular mechanisms that regulate vocalization over behaviorally relevant timescales, spanning milliseconds to hours and seasons. To our knowledge, this is the first comprehensive characterization of gene expression in a dedicated vocal motor nucleus. Candidate genes identified here may belong to a conserved genetic toolkit for vocal motoneurons facing similar energetic and neurophysiological demands. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1577-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ni Y Feng
- Department of Neurobiology and Behavior, Cornell University, 14853, Ithaca, NY, USA.
| | - Daniel J Fergus
- Department of Neurobiology and Behavior, Cornell University, 14853, Ithaca, NY, USA. .,Current Address: North Carolina Museum of Natural Sciences, Genomics and Microbiology, 27601, Raleigh, NC, USA.
| | - Andrew H Bass
- Department of Neurobiology and Behavior, Cornell University, 14853, Ithaca, NY, USA.
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17
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A single testosterone pulse rapidly reduces urinary marking behaviour in subordinate, but not dominant, white-footed mice. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2014.11.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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18
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Pradhan DS, Connor KR, Pritchett EM, Grober MS. Contextual modulation of androgen effects on agonistic interactions. Horm Behav 2014; 65:47-56. [PMID: 24315925 DOI: 10.1016/j.yhbeh.2013.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 11/23/2013] [Accepted: 11/25/2013] [Indexed: 12/15/2022]
Abstract
Seasonal changes in steroid hormones are known to have a major impact on social behavior, but often are quite sensitive to environmental context. In the bi-directionally sex changing fish, Lythrypnus dalli, stable haremic groups exhibit baseline levels of interaction. Status instability follows immediately after male removal, causing transiently elevated agonistic interactions and increase in brain and systemic levels of a potent fish androgen, 11-ketotestosterone (KT). Coupling KT implants with a socially inhibitory environment for protogynous sex change induces rapid transition to male morphology, but no significant change in social behavior and status, which could result from systemically administered steroids not effectively penetrating into brain or other tissues. Here, we first determined the degree to which exogenously administered steroids affect the steroid load within tissues. Second, we examined whether coupling a social environment permissive to sex change would influence KT effects on agonistic behavior. We implanted cholesterol (Chol, control) or KT in the dominant individual (alpha) undergoing sex change (on d0) and determined the effects on behavior and the degree to which administered steroids altered the steroid load within tissues. During the period of social instability, there were rapid (within 2 h), but transient effects of KT on agonistic behavior in alphas, and secondary effects on betas. On d3 and d5, all KT, but no Chol, treated females had male typical genital papillae. Despite elevated brain and systemic KT 5 days after implant, overall rates of aggressive behavior remained unaffected. These data highlight the importance of social context in mediating complex hormone-behavior relationships.
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Affiliation(s)
- D S Pradhan
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA.
| | - K R Connor
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA
| | - E M Pritchett
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA
| | - M S Grober
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA; Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
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19
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Maruska KP, Fernald RD. Social regulation of male reproductive plasticity in an African cichlid fish. Integr Comp Biol 2013; 53:938-50. [PMID: 23613320 PMCID: PMC3836007 DOI: 10.1093/icb/ict017] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Social interactions with the outcome of a position in a dominance hierarchy can have profound effects on reproductive behavior and physiology, requiring animals to integrate environmental information with their internal physiological state; but how is salient information from the animal's dynamic social environment transformed into adaptive behavioral, physiological, and molecular-level changes? The African cichlid fish, Astatotilapia burtoni, is ideally suited to understand socially controlled reproductive plasticity because activity of the male reproductive (brain-pituitary-gonad) axis is tightly linked to social status. Males form hierarchies in which a small percentage of brightly colored dominant individuals have an active reproductive axis, defend territories, and spawn with females, while the remaining males are subordinate, drably colored, do not hold a territory, and have a suppressed reproductive system with minimal opportunities for spawning. These social phenotypes are plastic and quickly reversible, meaning that individual males may switch between dominant and subordinate status multiple times within a lifetime. Here, we review the rapid and remarkable plasticity that occurs along the entire reproductive axis when males rise in social rank, a transition that has important implications for the operational sex ratio of the population. When males rise in rank, transformations occur in the brain, pituitary, circulation, and testes over short time-scales (minutes to days). Changes are evident in overt behavior, as well as modifications at the physiological, cellular, and molecular levels that regulate reproductive capacity. Widespread changes triggered by a switch in rank highlight the significance of external social information in shaping internal physiology and reproductive competence.
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Affiliation(s)
- Karen P. Maruska
- *Department of Biology, Stanford University, Stanford, CA 94305, USA; Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Russell D. Fernald
- *Department of Biology, Stanford University, Stanford, CA 94305, USA; Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
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20
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Pereira R, Rismondo S, Caiano M, Pedroso SS, Fonseca PJ, Amorim MCP. The Role of Agonistic Sounds in Male Nest Defence in the Painted GobyPomatoschistus pictus. Ethology 2013. [DOI: 10.1111/eth.12180] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ricardo Pereira
- Departamento de Biologia Animal e Centro de Biologia Ambiental; Faculdade de Ciências da Universidade de Lisboa; Lisboa Portugal
| | - Stefania Rismondo
- Departamento de Biologia Animal e Centro de Biologia Ambiental; Faculdade de Ciências da Universidade de Lisboa; Lisboa Portugal
| | - Manuel Caiano
- Departamento de Biologia Animal e Centro de Biologia Ambiental; Faculdade de Ciências da Universidade de Lisboa; Lisboa Portugal
| | - Silvia S. Pedroso
- Unidade de Investigação em Eco-Etologia; Instituto Superior de Psicologia Aplicada - Instituto Universitário; Lisboa Portugal
| | - Paulo J. Fonseca
- Departamento de Biologia Animal e Centro de Biologia Ambiental; Faculdade de Ciências da Universidade de Lisboa; Lisboa Portugal
| | - Maria Clara P. Amorim
- Unidade de Investigação em Eco-Etologia; Instituto Superior de Psicologia Aplicada - Instituto Universitário; Lisboa Portugal
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21
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Fergus DJ, Bass AH. Localization and divergent profiles of estrogen receptors and aromatase in the vocal and auditory networks of a fish with alternative mating tactics. J Comp Neurol 2013; 521:2850-69. [PMID: 23460422 PMCID: PMC3688646 DOI: 10.1002/cne.23320] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 02/11/2013] [Accepted: 02/13/2013] [Indexed: 11/06/2022]
Abstract
Estrogens play a salient role in the development and maintenance of both male and female nervous systems and behaviors. The plainfin midshipman (Porichthys notatus), a teleost fish, has two male reproductive morphs that follow alternative mating tactics and diverge in multiple somatic, hormonal, and neural traits, including the central control of morph-specific vocal behaviors. After we identified duplicate estrogen receptors (ERβ1 and ERβ2) in midshipman, we developed antibodies to localize protein expression in the central vocal-acoustic networks and saccule, the auditory division of the inner ear. As in other teleost species, ERβ1 and ERβ2 were robustly expressed in the telencephalon and hypothalamus in vocal-acoustic and other brain regions shown previously to exhibit strong expression of ERα and aromatase (estrogen synthetase, CYP19) in midshipman. Like aromatase, ERβ1 label colocalized with glial fibrillary acidic protein (GFAP) in telencephalic radial glial cells. Quantitative polymerase chain reaction revealed similar patterns of transcript abundance across reproductive morphs for ERβ1, ERβ2, ERα, and aromatase in the forebrain and saccule. In contrast, transcript abundance for ERs and aromatase varied significantly between morphs in and around the sexually polymorphic vocal motor nucleus (VMN). Together, the results suggest that VMN is the major estrogen target within the estrogen-sensitive hindbrain vocal network that directly determines the duration, frequency, and amplitude of morph-specific vocalizations. Comparable regional differences in steroid receptor abundances likely regulate morph-specific behaviors in males and females of other species exhibiting alternative reproductive tactics.
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Affiliation(s)
- Daniel J Fergus
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853, USA
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22
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O'Connell LA, Ding JH, Hofmann HA. Sex differences and similarities in the neuroendocrine regulation of social behavior in an African cichlid fish. Horm Behav 2013; 64:468-76. [PMID: 23899762 DOI: 10.1016/j.yhbeh.2013.07.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 07/21/2013] [Indexed: 01/13/2023]
Abstract
An individual's position in a social hierarchy profoundly affects behavior and physiology through interactions with community members, yet little is known about how the brain contributes to status differences between and within the social states or sexes. We aimed to determine sex-specific attributes of social status by comparing circulating sex steroid hormones and neural gene expression of sex steroid receptors in dominant and subordinate male and female Astatotilapia burtoni, a highly social African cichlid fish. We found that testosterone and 17β-estradiol levels are higher in males regardless of status and dominant individuals regardless of sex. Progesterone was found to be higher in dominant individuals regardless of sex. Based on pharmacological manipulations in males and females, progesterone appears to be a common mechanism for promoting courtship in dominant individuals. We also examined expression of androgen receptors, estrogen receptor α, and the progesterone receptor in five brain regions that are important for social behavior. Most of the differences in brain sex steroid receptor expression were due to sex rather than status. Our results suggest that the parvocellular preoptic area is a core region for mediating sex differences through androgen and estrogen receptor expression, whereas the progesterone receptor may mediate sex and status behaviors in the putative homologs of the nucleus accumbens and ventromedial hypothalamus. Overall our results suggest sex differences and similarities in the regulation of social dominance by gonadal hormones and their receptors in the brain.
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Affiliation(s)
- Lauren A O'Connell
- Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX 78705, USA; Section of Integrative Biology, University of Texas at Austin, Austin, TX 78705, USA
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23
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Sessa AK, Harris RM, Hofmann HA. Sex steroid hormones modulate responses to social challenge and opportunity in males of the monogamous convict cichlid, Amatitliana nigrofasciata. Gen Comp Endocrinol 2013; 189:59-65. [PMID: 23651580 DOI: 10.1016/j.ygcen.2013.04.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 04/02/2013] [Accepted: 04/26/2013] [Indexed: 10/26/2022]
Abstract
Steroid hormones play an important role in modulating behavioral responses to various social stimuli. It has been suggested that variation in the hormonal regulation of behavior across species is associated with social organization and/or mating system. In order to further elucidate the interplay of hormones and behavior in social situations, we exposed males of the monogamous convict cichlid Amatitliana nigrofasciata to three social stimuli: gravid female, intruder male, and a nonsocial stimulus. We used a repeated measure design to create behavioral profiles and explore how sex steroid hormones respond to and regulate social behavior. Results show distinct behavioral responses to different social situations, with circulating 11-ketotestosterone increasing in response to social stimuli. Pharmacological manipulations using specific androgen and estrogen receptor agonists and antagonists exposed complex control over digging behavior in the social opportunity context. In the social challenge context, aggressive behaviors decreased in response to blocking the androgen receptor pathway. Our results extend our understanding of sex steroid regulation of behavioral responses to social stimulation.
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Affiliation(s)
- Anna K Sessa
- Section of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
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24
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Maruska KP, Zhang A, Neboori A, Fernald RD. Social opportunity causes rapid transcriptional changes in the social behaviour network of the brain in an African cichlid fish. J Neuroendocrinol 2013; 25:145-57. [PMID: 22958303 PMCID: PMC3537875 DOI: 10.1111/j.1365-2826.2012.02382.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 08/11/2012] [Accepted: 09/02/2012] [Indexed: 10/27/2022]
Abstract
Animals constantly integrate external stimuli with their own internal physiological state to make appropriate behavioural decisions. Little is known, however, about where in the brain the salience of these signals is evaluated, or which neural and transcriptional mechanisms link this integration to adaptive behaviours. We used an African cichlid fish Astatotilapia burtoni to test the hypothesis that a new social opportunity activates the conserved 'social behaviour network' (SBN), a collection of brain nuclei known to regulate social behaviours across vertebrates. We measured mRNA levels of immediate early genes (IEGs) in microdissected brain regions as a proxy for neuronal activation, and discovered that IEGs were higher in all SBN nuclei in males that were given an opportunity to rise in social rank compared to control stable subordinate and dominant individuals. Furthermore, because the presence of sex-steroid receptors is one defining criteria of SBN nuclei, we also tested whether social opportunity or status influenced androgen and oestrogen receptor mRNA levels within these same regions. There were several rapid region-specific changes in receptor mRNA levels induced by social opportunity, most notably in oestrogen receptor subtypes in areas that regulate social aggression and reproduction, suggesting that oestrogenic signalling pathways play an important role in regulating male status. Several receptor mRNA changes occurred in regions with putative homologies to the mammalian septum and extended amygdala, two regions shared by SBN and reward circuits, suggesting an important role in the integration of social salience, stressors, hormonal state and adaptive behaviours. We also demonstrated increases in plasma sex- and stress-steroids at 30 min after a rise in social rank. This rapid endocrine and transcriptional response suggests that the SBN is involved in the integration of social inputs with internal hormonal state to facilitate the transition to dominant status, which ultimately leads to improved fitness for the previously reproductively-suppressed individual.
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Affiliation(s)
- K P Maruska
- Department of Biology, Stanford University, Stanford, CA, USA.
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25
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Lorenzi V, Earley RL, Grober MS. Differential responses of brain, gonad and muscle steroid levels to changes in social status and sex in a sequential and bidirectional hermaphroditic fish. PLoS One 2012; 7:e51158. [PMID: 23251444 PMCID: PMC3519529 DOI: 10.1371/journal.pone.0051158] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 10/30/2012] [Indexed: 01/06/2023] Open
Abstract
Sex steroids can both modulate and be modulated by behavior, and their actions are mediated by complex interactions among multiple hormone sources and targets. While gonadal steroids delivered via circulation can affect behavior, changes in local brain steroid synthesis also can modulate behavior. The relative steroid load across different tissues and the association of these levels with rates of behavior have not been well studied. The bluebanded goby (Lythrypnus dalli) is a sex changing fish in which social status determines sexual phenotype. We examined changes in steroid levels in brain, gonad and body muscle at either 24 hours or 6 days after social induction of protogynous sex change, and from individuals in stable social groups not undergoing sex change. For each tissue, we measured levels of estradiol (E(2)), testosterone (T) and 11-ketotestosterone (KT). Females had more T than males in the gonads, and more E(2) in all tissues but there was no sex difference in KT. For both sexes, E(2) was higher in the gonad than in other tissues while androgens were higher in the brain. During sex change, brain T levels dropped while brain KT increased, and brain E(2) levels did not change. We found a positive relationship between androgens and aggression in the most dominant females but only when the male was removed from the social group. The results demonstrate that steroid levels are responsive to changes in the social environment, and that their concentrations vary in different tissues. Also, we suggest that rapid changes in brain androgen levels might be important in inducing behavioral and/or morphological changes associated with protogynous sex change.
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Affiliation(s)
- Varenka Lorenzi
- Department of Biology and Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA, USA.
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26
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Schade J, Stallsmith B. Investigation of the Relationship between the Steroid Hormone 11-Ketotestosterone and Reproductive Status in the Fish Lythrurus fasciolaris. AMERICAN MIDLAND NATURALIST 2012. [DOI: 10.1674/0003-0031-168.1.218] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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27
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Mangiamele LA, Thompson RR. Testosterone rapidly increases ejaculate volume and sperm density in competitively breeding goldfish through an estrogenic membrane receptor mechanism. Horm Behav 2012; 62:107-12. [PMID: 22613707 DOI: 10.1016/j.yhbeh.2012.05.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 05/07/2012] [Accepted: 05/10/2012] [Indexed: 01/02/2023]
Abstract
The social environment can have dramatic influences on reproductive behavior and physiology in many vertebrate species. In males, interactions with conspecifics affect physiological processes that increase an individual's ability to compete for mates. For example, in some species, males rapidly adjust the number of sperm they ejaculate in response to sociosexual cues from male and female conspecifics, however, little is known about the physiological mechanisms mediating this behavior. In goldfish, as in many vertebrates, social cues also drive transient surges of the gonadal hormone testosterone (T), which induces rapid effects on cellular processes via its conversion to estradiol (E2). We asked whether such surges rapidly influence ejaculate quantity and quality by experimentally manipulating peripheral levels of T and E2. We show that male goldfish injected with T increased ejaculate (milt) volume and sperm density within just 1 hr. Furthermore, increases in expressible milt were dependent on the conversion of T to E2 by the enzyme aromatase, required activation of estrogen receptors α and β, and were also elicited by BSA-conjugated E2, which acts on cell membrane-bound estrogen receptors. Together, these findings represent a novel steroid mechanism for the social modulation of sperm output over the short time scales that characterize reproductive encounters, and thus demonstrate a previously undescribed functional consequence of rapid estrogen signaling mechanisms. We suggest that such mechanisms may play a critical role in the enhancement of physiological and behavioral processes that increase reproductive success in competitive mating contexts.
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Affiliation(s)
- Lisa A Mangiamele
- Department of Psychology, Bowdoin College, Brunswick, ME 04011‐8469, USA.
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28
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Mowrey WR, Portman DS. Sex differences in behavioral decision-making and the modulation of shared neural circuits. Biol Sex Differ 2012; 3:8. [PMID: 22436578 PMCID: PMC3352037 DOI: 10.1186/2042-6410-3-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 03/21/2012] [Indexed: 11/10/2022] Open
Abstract
Animals prioritize behaviors according to their physiological needs and reproductive goals, selecting a single behavioral strategy from a repertoire of possible responses to any given stimulus. Biological sex influences this decision-making process in significant ways, differentiating the responses animals choose when faced with stimuli ranging from food to conspecifics. We review here recent work in invertebrate models, including C. elegans, Drosophila, and a variety of insects, mollusks and crustaceans, that has begun to offer intriguing insights into the neural mechanisms underlying the sexual modulation of behavioral decision-making. These findings show that an animal's sex can modulate neural function in surprisingly diverse ways, much like internal physiological variables such as hunger or thirst. In the context of homeostatic behaviors such as feeding, an animal's sex and nutritional status may converge on a common physiological mechanism, the functional modulation of shared sensory circuitry, to influence decision-making. Similarly, considerable evidence suggests that decisions on whether to mate or fight with conspecifics are also mediated through sex-specific neuromodulatory control of nominally shared neural circuits. This work offers a new perspective on how sex differences in behavior emerge, in which the regulated function of shared neural circuitry plays a crucial role. Emerging evidence from vertebrates indicates that this paradigm is likely to extend to more complex nervous systems as well. As men and women differ in their susceptibility to a variety of neuropsychiatric disorders affecting shared behaviors, these findings may ultimately have important implications for human health.
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Affiliation(s)
- William R Mowrey
- Center for Neural Development and Disease, School of Medicine and Dentistry, University of Rochester, 601 Elmwood Avenue, Box 645, Rochester, NY 14642, USA.
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29
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O'Connell LA, Hofmann HA. Social status predicts how sex steroid receptors regulate complex behavior across levels of biological organization. Endocrinology 2012; 153:1341-51. [PMID: 22166981 DOI: 10.1210/en.2011-1663] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Social status strongly affects behavior and physiology, in part mediated by gonadal hormones, although how each sex steroid acts across levels of biological organization is not well understood. We examine the role of sex steroids in modulating social behavior in dominant (DOM) and subordinate (SUB) males of a highly social fish, Astatotilapia burtoni. We first used agonists and antagonists to each sex steroid receptor and found that androgens and progestins modulate courtship behavior only in DOM, whereas estrogens modulate aggressive behavior independent of social status. We then examined the hormonal and physiological responses to sex steroid receptor antagonist treatment and uncovered substantial changes in circulating steroid hormone levels and gonad size only in SUB, not in DOM. Consistent with status-based physiological sensitivities to drug manipulation, we found that neuropeptide and steroid receptor gene expression in the preoptic area was sensitive only in SUB. However, when we compared the transcriptomes of males that received either vehicle or an estrogen receptor antagonist, 8.25% of all genes examined changed expression in DOM in comparison with only 0.56% in SUB. Finally, we integrate behavior, physiology, and brain gene expression to infer functional modules that underlie steroid receptor regulation of behavior. Our work suggests that environmentally induced changes at one level of biological organization do not simply affect changes of similar magnitude at other levels, but that instead very few key pathways likely serve as conduits for executing plastic responses across multiple levels.
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Affiliation(s)
- Lauren A O'Connell
- Section of Integrative Biology, The University of Texas at Austin, 1 University Station C0930, Austin, Texas 78712, USA
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30
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Ellis T, Yildiz HY, López-Olmeda J, Spedicato MT, Tort L, Øverli Ø, Martins CIM. Cortisol and finfish welfare. FISH PHYSIOLOGY AND BIOCHEMISTRY 2012; 38:163-188. [PMID: 22113503 DOI: 10.1007/s10695-011-9568-y] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Accepted: 10/24/2011] [Indexed: 05/31/2023]
Abstract
Previous reviews of stress, and the stress hormone cortisol, in fish have focussed on physiology, due to interest in impacts on aquaculture production. Here, we discuss cortisol in relation to fish welfare. Cortisol is a readily measured component of the primary (neuroendocrine) stress response and is relevant to fish welfare as it affects physiological and brain functions and modifies behaviour. However, we argue that cortisol has little value if welfare is viewed purely from a functional (or behavioural) perspective-the cortisol response itself is a natural, adaptive response and is not predictive of coping as downstream impacts on function and behaviour are dose-, time- and context-dependent and not predictable. Nevertheless, we argue that welfare should be considered in terms of mental health and feelings, and that stress in relation to welfare should be viewed as psychological, rather than physiological. We contend that cortisol can be used (with caution) as a tractable indicator of how fish perceive (and feel about) their environment, psychological stress and feelings in fish. Cortisol responses are directly triggered by the brain and fish studies do indicate cortisol responses to psychological stressors, i.e., those with no direct physicochemical action. We discuss the practicalities of using cortisol to ask the fish themselves how they feel about husbandry practices and the culture environment. Single time point measurements of cortisol are of little value in assessing the stress level of fish as studies need to account for diurnal and seasonal variations, and environmental and genetic factors. Areas in need of greater clarity for the use of cortisol as an indicator of fish feelings are the separation of (physiological) stress from (psychological) distress, the separation of chronic stress from acclimation, and the interactions between feelings, cortisol, mood and behaviour.
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Affiliation(s)
- Tim Ellis
- Cefas Weymouth Laboratory, Weymouth, Dorset, UK.
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31
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Abstract
Within the CNS of vertebrates, estrogens can directly modulate neural circuits that govern a wide range of behaviors, including feeding, spatial navigation, reproduction, and auditory processing. The rapid actions of estrogens in brain (seconds to minutes) have become well established, but it is unclear how estrogens are synthesized and released within restricted temporal and spatial domains in neural circuits. Anatomical localization of the estrogen synthesis enzyme (aromatase) within presynaptic terminals suggests that neuroestrogens can be synthesized directly at the neuronal synapse. A consequent prediction follows that synaptic estrogen production is controlled via classical electrochemical events in neurons. Here, we present evidence that acute fluctuations in local neuroestrogen levels in the forebrain of the zebra finch depend on calcium influx within presynaptic terminals. In vivo experiments using microdialysis linked to a sensitive estrogen ELISA showed that local forebrain neuroestrogens were both suppressed by potassium-evoked excitation and upregulated during 30 min periods of extracellular calcium depletion in a region enriched with presynaptic aromatase. Furthermore, potassium-evoked changes in local neuroestrogens were blocked by targeted delivery of the voltage-gated calcium channel blocker ω-conotoxin GVIA. Together, these experiments indicate that neuroestrogens are controlled by specific, depolarization-sensitive, calcium-dependent events within forebrain presynaptic terminals.
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32
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Saldanha CJ, Remage-Healey L, Schlinger BA. Synaptocrine signaling: steroid synthesis and action at the synapse. Endocr Rev 2011; 32:532-49. [PMID: 21622487 PMCID: PMC3369574 DOI: 10.1210/er.2011-0004] [Citation(s) in RCA: 198] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Sex steroids have long been recognized for their dramatic impact on brain and behavior, including rapid modulation of membrane excitability. It is a widely held perception that these molecules are largely derived from peripheral sources and lack the spatial and temporal specificity ascribed to classical neuromodulatory systems. Neuromodulatory systems, in contrast, are defined by their regulated neuronal presynaptic secretion and by their functional modulation of perisynaptic events. Here we provide evidence for regulated presynaptic estrogen synthesis and functional postsynaptic actions. These results meet all the criteria for a neuromodulatory system and shift our perception of estrogens from that of peripheral signals exclusively to include that of a signaling system intrinsic to the brain itself. We apply the term synaptocrine to describe this form of neuromodulation.
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Affiliation(s)
- Colin J Saldanha
- Departments of Integrative Biology and Physiology, Ecology and Evolutionary Biology, University of California-Los Angeles, USA
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O'Connell LA, Hofmann HA. Genes, hormones, and circuits: an integrative approach to study the evolution of social behavior. Front Neuroendocrinol 2011; 32:320-35. [PMID: 21163292 DOI: 10.1016/j.yfrne.2010.12.004] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 12/03/2010] [Accepted: 12/09/2010] [Indexed: 12/23/2022]
Abstract
Tremendous progress has been made in our understanding of the ultimate and proximate mechanisms underlying social behavior, yet an integrative evolutionary analysis of its underpinnings has been difficult. In this review, we propose that modern genomic approaches can facilitate such studies by integrating four approaches to brain and behavior studies: (1) animals face many challenges and opportunities that are ecologically and socially equivalent across species; (2) they respond with species-specific, yet quantifiable and comparable approach and avoidance behaviors; (3) these behaviors in turn are regulated by gene modules and neurochemical codes; and (4) these behaviors are governed by brain circuits such as the mesolimbic reward system and the social behavior network. For each approach, we discuss genomic and other studies that have shed light on various aspects of social behavior and its underpinnings and suggest promising avenues for future research into the evolution of neuroethological systems.
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Affiliation(s)
- Lauren A O'Connell
- Institute for Cellular and Molecular Biology, Section of Integrative Biology, University of Texas at Austin, Austin, TX 78705, USA
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O’Connell LA, Ding JH, Ryan MJ, Hofmann HA. Neural distribution of the nuclear progesterone receptor in the túngara frog, Physalaemus pustulosus. J Chem Neuroanat 2011; 41:137-47. [DOI: 10.1016/j.jchemneu.2011.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 12/24/2010] [Accepted: 01/03/2011] [Indexed: 11/28/2022]
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Black MP, Balthazart J, Baillien M, Grober MS. Rapid increase in aggressive behavior precedes the decrease in brain aromatase activity during socially mediated sex change in Lythrypnus dalli. Gen Comp Endocrinol 2011; 170:119-24. [PMID: 20888827 PMCID: PMC3010447 DOI: 10.1016/j.ygcen.2010.09.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 08/26/2010] [Accepted: 09/22/2010] [Indexed: 12/17/2022]
Abstract
In the bluebanded goby, Lythrypnus dalli, removal of the male from a social group results in a rapid behavioral response where one female becomes dominant and changes sex to male. In a previous study, within hours of male removal, aromatase activity in the brain (bAA) of dominant females was almost 50% lower than that of control females from a group in which the male had not been removed. For those females that displayed increased aggressive behavior after the male was removed, the larger the increase in aggressive behavior, the greater the reduction in bAA. To investigate whether decreased bAA leads to increased aggression, the present study used a more rapid time course of behavioral profiling and bAA assay, looking within minutes of male removal from the group. There were no significant differences in bAA between control females (large females from groups with the male still present), females that doubled their aggressive behavior by 10 or 20 min after male removal, or females that did not double their aggressive behavior within 30 min after male removal. Further, individual variation in bAA and aggressive behavior were not correlated in these fish. Whole brain decreases in aromatase activity thus appear to follow, rather than precede, rapid increases in aggressive behavior, which provides one potential mechanism underlying the rapid increase in androgens that follows aggressive interactions in many vertebrate species. For fish species that change sex from female to male, this increase in androgens could subsequently facilitate sex change.
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Affiliation(s)
- Michael P Black
- Center for Behavioral Neuroscience, Neuroscience Institute, Georgia State University, Atlanta, GA 30302-3966, USA.
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Remage-Healey L, Saldanha CJ, Schlinger BA. Estradiol synthesis and action at the synapse: evidence for "synaptocrine" signaling. Front Endocrinol (Lausanne) 2011; 2:28. [PMID: 22654800 PMCID: PMC3356004 DOI: 10.3389/fendo.2011.00028] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 08/26/2011] [Indexed: 02/01/2023] Open
Abstract
Classically, the modulation of brain function and behavior by steroid hormones was linked exclusively to secretion by peripheral endocrine glands. Subsequently, steroid actions within the brain were shown dependent upon either synthesis and secretion by peripheral organs or by production within the CNS itself using peripheral sources of precursors. Discovery of the estrogen-synthetic enzyme aromatase in brain further bolstered the latter view and served as a catalyst for expanding concepts of neurosteroidogenesis. In parallel research, several steroids, including estradiol, were found to have rapid effects on neuronal excitability, partially explained by novel actions at neuronal membranes. Recent findings from multiple levels of analysis and labs necessitate an updated view on how steroids are delivered to neural circuits. There is now considerable evidence for expression of the aromatase enzyme within synaptic boutons in the vertebrate CNS. Furthermore, additional work now directly couples rapid regulation of neuroestrogen synthesis with neurophysiological and behavioral outcomes. In this review we summarize evidence for targeted and acute synaptic estrogen synthesis and perisynaptic estrogen actions in the CNS of songbirds. We evaluate these findings in the context of criteria associated with classic neuromodulatory signaling. We term this novel form of signaling "synaptocrine," and discuss its implications.
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Affiliation(s)
- Luke Remage-Healey
- Neuroscience and Behavior Program, Center for Neuroendocrine Studies, University of MassachusettsAmherst, MA, USA
| | | | - Barney A. Schlinger
- Department of Integrative Biology and Physiology, University of California at Los AngelesLos Angeles, CA, USA
- Ecology and Evolutionary Biology, University of California at Los AngelesLos Angeles, CA, USA
- Laboratory for Neuroendocrinology, University of California at Los AngelesLos Angeles, CA, USA
- *Correspondence: Barney A. Schlinger, Department of Integrative Biology and Physiology and Ecology and Evolutionary Biology, University of California at Los Angeles, 621 Charles E Young Drive South, Los Angeles, CA 90095, USA. e-mail:
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Balthazart J, Charlier TD, Cornil CA, Dickens MJ, Harada N, Konkle ATM, Voigt C, Ball GF. Sex differences in brain aromatase activity: genomic and non-genomic controls. Front Endocrinol (Lausanne) 2011; 2:34. [PMID: 22645508 PMCID: PMC3355826 DOI: 10.3389/fendo.2011.00034] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 09/02/2011] [Indexed: 11/22/2022] Open
Abstract
Aromatization of testosterone into estradiol in the preoptic area plays a critical role in the activation of male copulation in quail and in many other vertebrate species. Aromatase expression in quail and in other birds is higher than in rodents and other mammals, which has facilitated the study of the controls and functions of this enzyme. Over relatively long time periods (days to months), brain aromatase activity (AA), and transcription are markedly (four- to sixfold) increased by genomic actions of sex steroids. Initial work indicated that the preoptic AA is higher in males than in females and it was hypothesized that this differential production of estrogen could be a critical factor responsible for the lack of behavioral activation in females. Subsequent studies revealed, however, that this enzymatic sex difference might contribute but is not sufficient to explain the sex difference in behavior. Studies of AA, immunoreactivity, and mRNA concentrations revealed that sex differences observed when measuring enzymatic activity are not necessarily observed when one measures mRNA concentrations. Discrepancies potentially reflect post-translational controls of the enzymatic activity. AA in quail brain homogenates is rapidly inhibited by phosphorylation processes. Similar rapid inhibitions occur in hypothalamic explants maintained in vitro and exposed to agents affecting intracellular calcium concentrations or to glutamate agonists. Rapid changes in AA have also been observed in vivo following sexual interactions or exposure to short-term restraint stress and these rapid changes in estrogen production modulate expression of male sexual behaviors. These data suggest that brain estrogens display most if not all characteristics of neuromodulators if not neurotransmitters. Many questions remain however concerning the mechanisms controlling these rapid changes in estrogen production and their behavioral significance.
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Affiliation(s)
- Jacques Balthazart
- Groupe Interdisciplinaire de Génoprotéomique Appliquée Neurosciences, University of LiegeLiege, Belgium
- *Correspondence: Jacques Balthazart, Research Group in Behavioral Neuroendocrinology, Groupe Interdisciplinaire de Génoprotéomique Appliquée Neurosciences, University of Liège, Avenue de l’Hopital, 1 (BAT. B36), B-4000 Liège 1, Belgium. e-mail:
| | - Thierry D. Charlier
- Groupe Interdisciplinaire de Génoprotéomique Appliquée Neurosciences, University of LiegeLiege, Belgium
| | - Charlotte A. Cornil
- Groupe Interdisciplinaire de Génoprotéomique Appliquée Neurosciences, University of LiegeLiege, Belgium
| | - Molly J. Dickens
- Groupe Interdisciplinaire de Génoprotéomique Appliquée Neurosciences, University of LiegeLiege, Belgium
| | - Nobuhiro Harada
- Molecular Genetics, Fujita Health UniversityToyoake, Aichi, Japan
| | - Anne T. M. Konkle
- Groupe Interdisciplinaire de Génoprotéomique Appliquée Neurosciences, University of LiegeLiege, Belgium
| | - Cornelia Voigt
- Groupe Interdisciplinaire de Génoprotéomique Appliquée Neurosciences, University of LiegeLiege, Belgium
| | - Gregory F. Ball
- Department of Psychological and Brain Science, Johns Hopkins UniversityBaltimore, MD, USA
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Soares MC, Bshary R, Fusani L, Goymann W, Hau M, Hirschenhauser K, Oliveira RF. Hormonal mechanisms of cooperative behaviour. Philos Trans R Soc Lond B Biol Sci 2010; 365:2737-50. [PMID: 20679116 DOI: 10.1098/rstb.2010.0151] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Research on the diversity, evolution and stability of cooperative behaviour has generated a considerable body of work. As concepts simplify the real world, theoretical solutions are typically also simple. Real behaviour, in contrast, is often much more diverse. Such diversity, which is increasingly acknowledged to help in stabilizing cooperative outcomes, warrants detailed research about the proximate mechanisms underlying decision-making. Our aim here is to focus on the potential role of neuroendocrine mechanisms on the regulation of the expression of cooperative behaviour in vertebrates. We first provide a brief introduction into the neuroendocrine basis of social behaviour. We then evaluate how hormones may influence known cognitive modules that are involved in decision-making processes that may lead to cooperative behaviour. Based on this evaluation, we will discuss specific examples of how hormones may contribute to the variability of cooperative behaviour at three different levels: (i) within an individual; (ii) between individuals and (iii) between species. We hope that these ideas spur increased research on the behavioural endocrinology of cooperation.
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Affiliation(s)
- Marta C Soares
- Instituto Superior de Psicologia Aplicada, Unidade de Investigação em Eco-Etologia, Integrative Behavioural Biology Group, 1149-041 Lisboa, Portugal.
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Munchrath LA, Hofmann HA. Distribution of sex steroid hormone receptors in the brain of an African cichlid fish, Astatotilapia burtoni. J Comp Neurol 2010; 518:3302-26. [PMID: 20575061 DOI: 10.1002/cne.22401] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sex steroid hormones released from the gonads play an important role in mediating social behavior across all vertebrates. Many effects of these gonadal hormones are mediated by nuclear steroid hormone receptors, which are crucial for integration in the brain of external (e.g., social) signals with internal physiological cues to produce an appropriate behavioral output. The African cichlid fish Astatotilapia burtoni presents an attractive model system for the study of how internal cues and external social signals are integrated in the brain as males display robust plasticity in the form of two distinct, yet reversible, behavioral and physiological phenotypes depending on the social environment. In order to better understand where sex steroid hormones act to regulate social behavior in this species, we have determined the distribution of the androgen receptor, estrogen receptor alpha, estrogen receptor beta, and progesterone receptor mRNA and protein throughout the telencephalon and diencephalon and some mesencephalic structures of A. burtoni. All steroid hormone receptors were found in key brain regions known to modulate social behavior in other vertebrates including the proposed teleost homologs of the mammalian amygdalar complex, hippocampus, striatum, preoptic area, anterior hypothalamus, ventromedial hypothalamus, and ventral tegmental area. Overall, there is high concordance of mRNA and protein labeling. Our results significantly extend our understanding of sex steroid pathways in the cichlid brain and support the important role of nuclear sex steroid hormone receptors in modulating social behaviors in teleosts and across vertebrates.
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Affiliation(s)
- Lauren A Munchrath
- Section of Integrative Biology, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78705, USA
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Stereotypy and variation of the mating call in the Lusitanian toadfish, Halobatrachus didactylus. Behav Ecol Sociobiol 2010. [DOI: 10.1007/s00265-010-1072-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kelley DB, Bass AH. Neurobiology of vocal communication: mechanisms for sensorimotor integration and vocal patterning. Curr Opin Neurobiol 2010; 20:748-53. [PMID: 20829032 DOI: 10.1016/j.conb.2010.08.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 08/10/2010] [Indexed: 01/22/2023]
Abstract
This review will focus on recent developments in the sensorimotor integration of vocal communication. Two broad themes are emphasized: the evolution of vocal production and perception, and the role of social context. Advances include: a proposal for the emergence of vocal patterning during vertebrate evolution, the role of sensory mechanisms such as categorical perception in decoding communication signals, contributions of sensorimotor integration phenomena including mirror neurons and vocal learning, and mechanisms of hormone-dependent plasticity in both auditory and vocal systems. Transcriptional networks activated in humans but not in chimps by the FoxP2 gene suggest molecular mechanisms underlying vocal gestures and the emergence of human language.
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Affiliation(s)
- Darcy B Kelley
- Department of Biological Sciences, MC2432, Columbia University, New York, NY 10025, USA.
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Salonia A, Giraldi A, Chivers ML, Georgiadis JR, Levin R, Maravilla KR, McCarthy MM. Physiology of Women's Sexual Function: Basic Knowledge and New Findings. J Sex Med 2010; 7:2637-60. [DOI: 10.1111/j.1743-6109.2010.01810.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Forlano PM, Marchaterre M, Deitcher DL, Bass AH. Distribution of androgen receptor mRNA expression in vocal, auditory, and neuroendocrine circuits in a teleost fish. J Comp Neurol 2010; 518:493-512. [PMID: 20020540 DOI: 10.1002/cne.22233] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Across all major vertebrate groups, androgen receptors (ARs) have been identified in neural circuits that shape reproductive-related behaviors, including vocalization. The vocal control network of teleost fishes presents an archetypal example of how a vertebrate nervous system produces social, context-dependent sounds. We cloned a partial cDNA of AR that was used to generate specific probes to localize AR expression throughout the central nervous system of the vocal plainfin midshipman fish (Porichthys notatus). In the forebrain, AR mRNA is abundant in proposed homologs of the mammalian striatum and amygdala, and in anterior and posterior parvocellular and magnocellular nuclei of the preoptic area, nucleus preglomerulosus, and posterior, ventral and anterior tuberal nuclei of the hypothalamus. Many of these nuclei are part of the known vocal and auditory circuitry in midshipman. The midbrain periaqueductal gray, an essential link between forebrain and hindbrain vocal circuitry, and the lateral line recipient nucleus medialis in the rostral hindbrain also express abundant AR mRNA. In the caudal hindbrain-spinal vocal circuit, high AR mRNA is found in the vocal prepacemaker nucleus and along the dorsal periphery of the vocal motor nucleus congruent with the known pattern of expression of aromatase-containing glial cells. Additionally, abundant AR mRNA expression is shown for the first time in the inner ear of a vertebrate. The distribution of AR mRNA strongly supports the role of androgens as modulators of behaviorally defined vocal, auditory, and neuroendocrine circuits in teleost fish and vertebrates in general.
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Affiliation(s)
- Paul M Forlano
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853, USA.
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Brain estrogens rapidly strengthen auditory encoding and guide song preference in a songbird. Proc Natl Acad Sci U S A 2010; 107:3852-7. [PMID: 20133597 DOI: 10.1073/pnas.0906572107] [Citation(s) in RCA: 172] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Higher cognitive function depends on accurate detection and processing of subtle features of sensory stimuli. Such precise computations require neural circuits to be modulated over rapid timescales, yet this modulation is poorly understood. Brain-derived steroids (neurosteroids) can act as fast signaling molecules in the vertebrate central nervous system and could therefore modulate sensory processing and guide behavior, but there is no empirical evidence for this possibility. Here we report that acute inhibition of estrogen production within a cortical-like region involved in complex auditory processing disrupts a songbird's ability to behaviorally respond to song stimuli. Identical manipulation of local estrogen levels rapidly changes burst firing of single auditory neurons. This acute estrogen-mediated modulation targets song and not other auditory stimuli, possibly enabling discrimination among species-specific signals. Our results demonstrate a crucial role for neuroestrogen synthesis among vertebrates for enhanced sensory encoding. Cognitive impairments associated with estrogen depletion, including verbal memory loss in humans, may therefore stem from compromised moment-by-moment estrogen actions in higher-order cortical circuits.
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Gleason ED, Marler CA. Testosterone response to courtship predicts future paternal behavior in the California mouse, Peromyscus californicus. Horm Behav 2010; 57:147-54. [PMID: 19833131 PMCID: PMC2814952 DOI: 10.1016/j.yhbeh.2009.10.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Revised: 10/05/2009] [Accepted: 10/05/2009] [Indexed: 11/17/2022]
Abstract
In the monogamous and biparental California mouse (Peromyscus californicus), paternal care is critical for maximal offspring survival. Animals form pair bonds and do not engage in extrapair matings, and thus female evaluation of paternal quality during courtship is likely to be advantageous. We hypothesized that male endocrine or behavioral response to courtship interactions would be predictive of future paternal behavior. To test this hypothesis, we formed 20 pairs of California mice, and evaluated their behavior during the first hour of courtship interactions and again following the birth of young. We also collected blood from males at baseline, 1 hr after pairing, 3 weeks paired, and when young were 4 days old to measure testosterone (T). We found that male T-response to courtship interactions predicted future paternal behavior, specifically the amount of time he huddled over young when challenged by the temporary removal of his mate. Males that mounted T increases at courtship also approached pups more quickly during this challenge than males who had a significant decrease in T at courtship. Proximity of the male and female during courtship predicted paternal huddling during a 1-hr observation, and a multiple regression analysis revealed that courtship behavior was also predictive of birth latency. We speculate that male T-response to a female in P. californicus is an honest indicator of paternal quality, and if detectable by females could provide a basis for evaluation during mate choice.
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Affiliation(s)
- Erin D Gleason
- Department of Psychology, University of Wisconsin-Madison, Madison, WI 53706, USA.
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Charlier TD, Cornil CA, Ball GF, Balthazart J. Diversity of mechanisms involved in aromatase regulation and estrogen action in the brain. Biochim Biophys Acta Gen Subj 2010; 1800:1094-105. [PMID: 20060879 DOI: 10.1016/j.bbagen.2009.12.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Revised: 12/10/2009] [Accepted: 12/31/2009] [Indexed: 12/19/2022]
Abstract
BACKGROUND The mechanisms through which estrogens modulate neuronal physiology, brain morphology, and behavior in recent years have proven to be far more complex than previously thought. For example, a second nuclear estrogen receptor has been identified, a new family of coregulatory proteins regulating steroid-dependent gene transcriptions was discovered and, finally, it has become clear that estrogens have surprisingly rapid effects based on their actions on cell membranes, which in turn result in the modulation of intracellular signaling cascades. SCOPE OF REVIEW This paper presents a selective review of new findings in this area related to work in our laboratories, focusing on the role of estrogens in the activation of male sexual behavior. Two separate topics are considered. We first discuss functions of the steroid receptor coactivator-1 (SRC-1) that has emerged as a key limiting factor for behavioral effects of estradiol. Knocking-down its expression by antisense oligonucleotides drastically inhibits male-typical sexual behaviors. Secondly, we describe rapid regulations of brain estradiol production by calcium-dependent phosphorylations of the aromatase enzyme, themselves under the control of neurotransmitter activity. MAJOR CONCLUSIONS These rapid changes in estrogen bioavailability have clear behavioral consequences. Increases or decreases in estradiol concentrations respectively obtained by an acute injection of estradiol itself or of an aromatase inhibitor lead within 15-30 min to parallel changes in sexual behavior frequencies. GENERAL SIGNIFICANCE These new controls of estrogen action offer a vast array of possibilities for discrete local controls of estrogen action. They also represent a formidable challenge for neuroendocrinologists trying to obtain an integrated view of brain function in relation to behavior.
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Schjolden J, Basic D, Winberg S. Aggression in rainbow trout is inhibited by both MR and GR antagonists. Physiol Behav 2009; 98:625-30. [DOI: 10.1016/j.physbeh.2009.09.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 09/18/2009] [Accepted: 09/25/2009] [Indexed: 11/28/2022]
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Abstract
Circulating hormone levels can mediate changes in the quality of courtship signals by males and/or mate choice by females and may thus play an important role in the evolution of courtship signals. Costs associated with shifts in hormone levels of males, for example, could effectively stabilize directional selection by females on male signals. Alternatively, if hormone levels affect the selection of mates by females, then variation in hormone levels among females could contribute to the maintenance of variability in the quality of males' signals. Here, I review what is known regarding the effects of hormone levels on the quality of acoustic signals produced by males and on the choice of mates by females in anuran amphibians. Surprisingly, despite the long history of anuran amphibians as model organisms for studying acoustic communication and physiology, we know very little about how variation in circulating hormone levels contributes to variation in the vocal quality of males. Proposed relationships between androgen levels and vocal quality depicted in recent models, for example, are subject to the same criticisms raised for similar models proposed in relation to birds, namely that the evidence for graded effects of androgens on vocal performance is often weak or not rigorously tested and responses seen in one species are often not observed in other species. Although several studies offer intriguing support for graded effects of hormones on calling behavior, additional comparative studies will be required to understand these relationships. Recent studies indicate that hormones may also mediate changes in anuran females' choice of mates, suggesting that the hormone levels of females can influence the evolution of males' mating signals. No studies to date have concurrently addressed the potential complexity of hormone-behavior relationships from the perspective of sender as well as receiver, nor have any studies addressed the costs that are potentially associated with changes in circulating hormone levels in anurans (i.e., life-history tradeoffs associated with elevations in circulating androgens in males). The mechanisms involved in hormonally induced changes in signal production and selectivity also require further investigation. Anuran amphibians are, in many ways, conducive to investigating such questions.
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The organization of feedback projections in a pathway important for processing pheromonal signals. Neuroscience 2009; 161:489-500. [PMID: 19341782 DOI: 10.1016/j.neuroscience.2009.03.065] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Revised: 03/23/2009] [Accepted: 03/23/2009] [Indexed: 01/21/2023]
Abstract
In most of the mammalian sensory systems there are massive cortical feedback projections to early processing stations. The mammalian accessory olfactory system is considered unique in several aspects. It is specialized for processing pheromonal signals and plays a critical role in regulating sociosexual behaviors. Furthermore, pheromonal signals are believed to bypass cortex and reach the hypothalamic behavioral centers after merely three forward projections. Because the organization of the feedback projections in the accessory olfactory system remains largely unclear, the importance of the feedback projections in the processing of pheromonal signals has been ignored. Here we show that in mice the feedback projections from the bed nucleus of stria terminalis (BST) and the vomeronasal amygdala to the accessory olfactory bulb (AOB) are topographically organized and use different neurotransmitters. By retrograde and anterograde tracing, we find that the feedback projection from the BST terminates in the AOB mitral cell layer, whereas that from the amygdala terminates in the AOB granule cell layer. By combining tracing, genetic labeling of GABAergic neurons, and immunostaining against a marker of glutamatergic synapses, we observe that the BST-to-AOB projection is GABAergic whereas the amygdala-to-AOB projection is glutamatergic. In addition, a substantial number of feedback neurons in the amygdala and BST express estrogen receptors. Thus, the accessory olfactory system, like other sensory systems, possesses extensive feedback projections. Moreover, our results suggest that central hormonal cues may modulate the processing of pheromonal signals at early stations through the precisely organized feedback projections.
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Meitzen J, Thompson CK, Choi H, Perkel DJ, Brenowitz EA. Time course of changes in Gambel's white-crowned sparrow song behavior following transitions in breeding condition. Horm Behav 2009; 55:217-27. [PMID: 19013173 PMCID: PMC2648829 DOI: 10.1016/j.yhbeh.2008.10.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 10/10/2008] [Accepted: 10/10/2008] [Indexed: 12/17/2022]
Abstract
Seasonal changes in behavior and in its underlying neural substrate are common across animal taxa. These changes are often triggered by steroid sex hormones. Song in seasonally breeding songbirds provides an excellent example of this phenomenon. In these species, dramatic seasonal changes mediated by testosterone and its metabolites occur in adult song behavior and in the neural circuitry controlling song. While song rate can quickly change in response to seasonal breeding cues, it is unknown how quickly other aspects of song change, particularly the stereotypy of song phonology and syntax. In this study we determined whether and how quickly song rate, phonology, and syntax change in response to breeding and non-breeding physiological cues. We asked these questions using Gambel's white-crowned sparrows (Zonotrichia leucophrys gambelii), a closed-ended learner with well-characterized changes in the neural circuitry controlling song behavior. We exposed ten photosensitive sparrows to long-day photoperiod and implanted them with subcutaneous testosterone pellets (day 0) to simulate breeding conditions. We continuously recorded song and found that song rate increased quickly, reaching maximum around day 6. The stereotypy of song phonology changed more slowly, reaching maximum by day 10 or later. Song syntax changed minimally after day 6, the earliest time point examined. After 21 days, we transitioned five birds from breeding to non-breeding condition. Song rate declined precipitously. These results suggest that while song rate changes quickly, song phonology changes more slowly, generally following or in parallel with previously investigated changes in the neural substrate.
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Affiliation(s)
- John Meitzen
- Graduate Program in Neurobiology and Behavior, University of Washington, Seattle, WA 98195, USA.
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