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Barkan CL, Zornik E. Inspiring song: The role of respiratory circuitry in the evolution of vertebrate vocal behavior. Dev Neurobiol 2020; 80:31-41. [PMID: 32329162 DOI: 10.1002/dneu.22752] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 04/18/2020] [Accepted: 04/19/2020] [Indexed: 12/18/2022]
Abstract
Vocalization is a common means of communication across vertebrates, but the evolutionary origins of the neural circuits controlling these behaviors are not clear. Peripheral mechanisms of sound production vary widely: fish produce sounds with a swimbladder or pectoral fins; amphibians, reptiles, and mammalians vocalize using a larynx; birds vocalize with a syrinx. Despite the diversity of vocal effectors across taxa, there are many similarities in the neural circuits underlying the control of these organs. Do similarities in vocal circuit structure and function indicate that vocal behaviors first arose in a single common ancestor, or have similar neural circuits arisen independently multiple times during evolution? In this review, we describe the hindbrain circuits that are involved in vocal production across vertebrates. Given that vocalization depends on respiration in most tetrapods, it is not surprising that vocal and respiratory hindbrain circuits across distantly related species are anatomically intermingled and functionally linked. Such vocal-respiratory circuit integration supports the hypothesis that vocal evolution involved the expansion and functional diversification of breathing circuits. Recent phylogenetic analyses, however, suggest vocal behaviors arose independently in all major tetrapod clades, indicating that similarities in vocal control circuits are the result of repeated co-options of respiratory circuits in each lineage. It is currently unknown whether vocal circuits across taxa are made up of homologous neurons, or whether vocal neurons in each lineage arose from developmentally and evolutionarily distinct progenitors. Integrative comparative studies of vocal neurons across brain regions and taxa will be required to distinguish between these two scenarios.
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Affiliation(s)
| | - Erik Zornik
- Biology Department, Reed College, Portland, OR, USA
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2
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Lovell PV, Wirthlin M, Kaser T, Buckner AA, Carleton JB, Snider BR, McHugh AK, Tolpygo A, Mitra PP, Mello CV. ZEBrA: Zebra finch Expression Brain Atlas-A resource for comparative molecular neuroanatomy and brain evolution studies. J Comp Neurol 2020; 528:2099-2131. [PMID: 32037563 DOI: 10.1002/cne.24879] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 01/22/2020] [Accepted: 01/25/2020] [Indexed: 12/14/2022]
Abstract
An in-depth understanding of the genetics and evolution of brain function and behavior requires a detailed mapping of gene expression in functional brain circuits across major vertebrate clades. Here we present the Zebra finch Expression Brain Atlas (ZEBrA; www.zebrafinchatlas.org, RRID: SCR_012988), a web-based resource that maps the expression of genes linked to a broad range of functions onto the brain of zebra finches. ZEBrA is a first of its kind gene expression brain atlas for a bird species and a first for any sauropsid. ZEBrA's >3,200 high-resolution digital images of in situ hybridized sections for ~650 genes (as of June 2019) are presented in alignment with an annotated histological atlas and can be browsed down to cellular resolution. An extensive relational database connects expression patterns to information about gene function, mouse expression patterns and phenotypes, and gene involvement in human diseases and communication disorders. By enabling brain-wide gene expression assessments in a bird, ZEBrA provides important substrates for comparative neuroanatomy and molecular brain evolution studies. ZEBrA also provides unique opportunities for linking genetic pathways to vocal learning and motor control circuits, as well as for novel insights into the molecular basis of sex steroids actions, brain dimorphisms, reproductive and social behaviors, sleep function, and adult neurogenesis, among many fundamental themes.
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Affiliation(s)
- Peter V Lovell
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon
| | - Morgan Wirthlin
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon
| | - Taylor Kaser
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon
| | - Alexa A Buckner
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon
| | - Julia B Carleton
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon
| | - Brian R Snider
- Center for Spoken Language Understanding, Institute on Development and Disability, Oregon Health and Science University, Portland, Oregon
| | - Anne K McHugh
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon
| | | | - Partha P Mitra
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York
| | - Claudio V Mello
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon
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Whitaker-Fornek JR, Nelson JK, Lybbert CW, Pilarski JQ. Development and regulation of breathing rhythms in embryonic and hatchling birds. Respir Physiol Neurobiol 2019; 269:103246. [DOI: 10.1016/j.resp.2019.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/19/2019] [Accepted: 06/23/2019] [Indexed: 11/28/2022]
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Pickett KL, Stein PS, Vincen-Brown MA, Pilarski JQ. Maturation of Breathing-Related Inhibitory Neurotransmission in the Medulla Oblongata of the Embryonic and Perinatal Zebra Finch (Taeniopygia guttata). Dev Neurobiol 2018; 78:1081-1096. [PMID: 30160056 PMCID: PMC6596416 DOI: 10.1002/dneu.22632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 07/07/2018] [Accepted: 07/08/2018] [Indexed: 11/05/2022]
Abstract
The medullary portion of the embryonic zebra finch hindbrain was isolated and superfused with physiologically relevant artificial cerebral spinal fluid. This in vitro preparation produced uninterrupted rhythmic episodes of neural activity via cranial nerve IX (glossopharyngeal) from embryonic day 4 (E4) through hatching on E14. Cranial nerve IX carries motor activity to the glottis during the inspiratory phase of breathing, and we focused on the role of synaptic inhibition during the embryonic and perinatal maturation of this branchiomotor outflow. We show that spontaneous neural activity (SNA) is first observed on E4 and temporally transforms as the embryo ages. To start, SNA is dependent on the excitatory actions of GABAA and glycine. As the embryo continues to develop, GABAergic and glycinergic neurotransmission take on a modulatory role, albeit an excitatory one, through E10. After that, data show that GABAergic and glycinergic neurotransmission switches to a phenotype consistent with inhibition, coincident with the onset of functional breathing. We also report that the inhibitory action of GABAergic and glycinergic receptor gating is not necessary for the spontaneous generation of branchiomotor motor rhythms in these birds near hatching. This is the first report focusing on the development of central breathing-related inhibitory neurotransmission in birds during the entire period of embryogenesis.
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Affiliation(s)
- Kaci L. Pickett
- Department of Biological Sciences, Idaho State University, Pocatello, ID. 83209-8007
| | - Paxton S. Stein
- Department of Biological Sciences, Idaho State University, Pocatello, ID. 83209-8007
| | | | - Jason Q. Pilarski
- Department of Biological Sciences, Idaho State University, Pocatello, ID. 83209-8007
- Department of Dental Sciences, Idaho State University, Pocatello, ID. 83209-8007
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Danish HH, Aronov D, Fee MS. Rhythmic syllable-related activity in a songbird motor thalamic nucleus necessary for learned vocalizations. PLoS One 2017; 12:e0169568. [PMID: 28617829 PMCID: PMC5472270 DOI: 10.1371/journal.pone.0169568] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 12/19/2016] [Indexed: 01/17/2023] Open
Abstract
Birdsong is a complex behavior that exhibits hierarchical organization. While the representation of singing behavior and its hierarchical organization has been studied in some detail in avian cortical premotor circuits, our understanding of the role of the thalamus in adult birdsong is incomplete. Using a combination of behavioral and electrophysiological studies, we seek to expand on earlier work showing that the thalamic nucleus Uvaeformis (Uva) is necessary for the production of stereotyped, adult song in zebra finch (Taeniopygia guttata). We confirm that complete bilateral lesions of Uva abolish singing in the ‘directed’ social context, but find that in the ‘undirected’ social context, such lesions result in highly variable vocalizations similar to early babbling song in juvenile birds. Recordings of neural activity in Uva reveal strong syllable-related modulation, maximally active prior to syllable onsets and minimally active prior to syllable offsets. Furthermore, both song and Uva activity exhibit a pronounced coherent modulation at 10Hz—a pattern observed in downstream premotor areas in adult and, even more prominently, in juvenile birds. These findings are broadly consistent with the idea that Uva is critical in the sequential activation of behavioral modules in HVC.
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Affiliation(s)
- Husain H. Danish
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Dmitriy Aronov
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Michale S. Fee
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- * E-mail:
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Central pattern generator for vocalization: is there a vertebrate morphotype? Curr Opin Neurobiol 2014; 28:94-100. [PMID: 25050813 DOI: 10.1016/j.conb.2014.06.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 05/11/2014] [Accepted: 06/22/2014] [Indexed: 11/21/2022]
Abstract
Animals that generate acoustic signals for social communication are faced with two essential tasks: generate a temporally precise signal and inform the auditory system about the occurrence of one's own sonic signal. Recent studies of sound producing fishes delineate a hindbrain network comprised of anatomically distinct compartments coding equally distinct neurophysiological properties that allow an organism to meet these behavioral demands. A set of neural characters comprising a vocal-sonic central pattern generator (CPG) morphotype is proposed for fishes and tetrapods that shares evolutionary developmental origins with pectoral appendage motor systems.
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Karim MR, Saito S, Atoji Y. Distribution of vesicular glutamate transporter 2 in auditory and song control brain regions in the adult zebra finch (Taeniopygia guttata). J Comp Neurol 2014; 522:2129-51. [DOI: 10.1002/cne.23522] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 12/05/2013] [Accepted: 12/06/2013] [Indexed: 12/20/2022]
Affiliation(s)
- Mohammad Rabiul Karim
- Department of Basic Veterinary Science; United Graduate School of Veterinary Sciences, Gifu University; Gifu 501-1193 Japan
- Department of Anatomy and Histology; Bangladesh Agricultural University; Mymensingh 2202 Bangladesh
| | - Shouichiro Saito
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences; Gifu University; Gifu 501-1193 Japan
| | - Yasuro Atoji
- Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences; Gifu University; Gifu 501-1193 Japan
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Schmidt MF, Martin Wild J. The respiratory-vocal system of songbirds: anatomy, physiology, and neural control. PROGRESS IN BRAIN RESEARCH 2014; 212:297-335. [PMID: 25194204 DOI: 10.1016/b978-0-444-63488-7.00015-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
This wide-ranging review presents an overview of the respiratory-vocal system in songbirds, which are the only other vertebrate group known to display a degree of respiratory control during song rivalling that of humans during speech; this despite the fact that the peripheral components of both the respiratory and vocal systems differ substantially in the two groups. We first provide a brief description of these peripheral components in songbirds (lungs, air sacs and respiratory muscles, vocal organ (syrinx), upper vocal tract) and then proceed to a review of the organization of central respiratory-related neurons in the spinal cord and brainstem, the latter having an organization fundamentally similar to that of the ventral respiratory group of mammals. The second half of the review describes the nature of the motor commands generated in a specialized "cortical" song control circuit and how these might engage brainstem respiratory networks to shape the temporal structure of song. We also discuss a bilaterally projecting "respiratory-thalamic" pathway that links the respiratory system to "cortical" song control nuclei. This necessary pathway for song originates in the brainstem's primary inspiratory center and is hypothesized to play a vital role in synchronizing song motor commands both within and across hemispheres.
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Affiliation(s)
- Marc F Schmidt
- Department of Biology and Neuroscience Program, University of Pennsylvania, Philadelphia, PA, USA.
| | - J Martin Wild
- Department of Anatomy with Radiology, School of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
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Wild JM, Balthazart J. Neural pathways mediating control of reproductive behavior in male Japanese quail. J Comp Neurol 2013; 521:2067-87. [PMID: 23225613 DOI: 10.1002/cne.23275] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 11/19/2012] [Accepted: 11/26/2012] [Indexed: 12/20/2022]
Abstract
The sexually dimorphic medial preoptic nucleus (POM) in Japanese quail has for many years been the focus of intensive investigations into its role in reproductive behavior. The present study delineates a sequence of descending pathways that finally reach sacral levels of the spinal cord housing motor neurons innervating cloacal muscles involved in reproductive behavior. We first retrogradely labeled the motor neurons innervating the large cloacal sphincter muscle (mSC) that forms part of the foam gland complex (Seiwert and Adkins-Regan [1998] Brain Behav Evol 52:61-80) and then putative premotor nuclei in the brainstem, one of which was nucleus retroambigualis (RAm) in the caudal medulla. Anterograde tracing from RAm defined a bulbospinal pathway, terminations of which overlapped the distribution of mSC motor neurons and their extensive dorsally directed dendrites. Descending input to RAm arose from an extensive dorsomedial nucleus of the intercollicular complex (DM-ICo), electrical stimulation of which drove vocalizations. POM neurons were retrogradely labeled by injections of tracer into DM-ICo, but POM projections largely surrounded DM, rather than penetrated it. Thus, although a POM projection to ICo was shown, a POM projection to DM must be inferred. Nevertheless, the sequence of projections in the male quail from POM to cloacal motor neurons strongly resembles that in rats, cats, and monkeys for the control of reproductive behavior, as largely defined by Holstege et al. ([1997], Neuroscience 80:587-598).
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Affiliation(s)
- J Martin Wild
- Department of Anatomy with Radiology, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand.
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11
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Düring DN, Ziegler A, Thompson CK, Ziegler A, Faber C, Müller J, Scharff C, Elemans CPH. The songbird syrinx morphome: a three-dimensional, high-resolution, interactive morphological map of the zebra finch vocal organ. BMC Biol 2013; 11:1. [PMID: 23294804 PMCID: PMC3539882 DOI: 10.1186/1741-7007-11-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 01/08/2013] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Like human infants, songbirds learn their species-specific vocalizations through imitation learning. The birdsong system has emerged as a widely used experimental animal model for understanding the underlying neural mechanisms responsible for vocal production learning. However, how neural impulses are translated into the precise motor behavior of the complex vocal organ (syrinx) to create song is poorly understood. First and foremost, we lack a detailed understanding of syringeal morphology. RESULTS To fill this gap we combined non-invasive (high-field magnetic resonance imaging and micro-computed tomography) and invasive techniques (histology and micro-dissection) to construct the annotated high-resolution three-dimensional dataset, or morphome, of the zebra finch (Taeniopygia guttata) syrinx. We identified and annotated syringeal cartilage, bone and musculature in situ in unprecedented detail. We provide interactive three-dimensional models that greatly improve the communication of complex morphological data and our understanding of syringeal function in general. CONCLUSIONS Our results show that the syringeal skeleton is optimized for low weight driven by physiological constraints on song production. The present refinement of muscle organization and identity elucidates how apposed muscles actuate different syringeal elements. Our dataset allows for more precise predictions about muscle co-activation and synergies and has important implications for muscle activity and stimulation experiments. We also demonstrate how the syrinx can be stabilized during song to reduce mechanical noise and, as such, enhance repetitive execution of stereotypic motor patterns. In addition, we identify a cartilaginous structure suited to play a crucial role in the uncoupling of sound frequency and amplitude control, which permits a novel explanation of the evolutionary success of songbirds.
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Affiliation(s)
- Daniel N Düring
- Verhaltensbiologie, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany
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Abstract
Vocalizations involve complex rhythmic motor patterns, but the underlying temporal coding mechanisms in the nervous system are poorly understood. Using a recently developed whole-brain preparation from which "fictive" vocalizations are readily elicited in vitro, we investigated the cellular basis of temporal complexity of African clawed frogs (Xenopus laevis). Male advertisement calls contain two alternating components--fast trills (∼300 ms) and slow trills (∼700 ms) that contain clicks repeated at ∼60 and ∼30 Hz, respectively. We found that males can alter the duration of fast trills without changing click rates. This finding led us to hypothesize that call rate and duration are regulated by independent mechanisms. We tested this by obtaining whole-cell patch-clamp recordings in the "fictively" calling isolated brain. We discovered a single type of premotor neuron with activity patterns correlated with both the rate and duration of fast trills. These "fast-trill neurons" (FTNs) exhibited long-lasting depolarizations (LLDs) correlated with each fast trill and action potentials that were phase-locked with motor output-neural correlates of call duration and rate, respectively. When depolarized without central pattern generator activation, FTNs produced subthreshold oscillations and action potentials at fast-trill rates, indicating FTN resonance properties are tuned to, and may dictate, the fast-trill rhythm. NMDA receptor (NMDAR) blockade eliminated LLDs in FTNs, and NMDAR activation in synaptically isolated FTNs induced repetitive LLDs. These results suggest FTNs contain an NMDAR-dependent mechanism that may regulate fast-trill duration. We conclude that a single premotor neuron population employs distinct mechanisms to regulate call rate and duration.
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Wild JM, Krützfeldt NEO. Trigeminal and telencephalic projections to jaw and other upper vocal tract premotor neurons in songbirds: sensorimotor circuitry for beak movements during singing. J Comp Neurol 2012; 520:590-605. [PMID: 21858818 DOI: 10.1002/cne.22752] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
During singing in songbirds, the extent of beak opening, like the extent of mouth opening in human singers, is partially correlated with the fundamental frequency of the sounds emitted. Since song in songbirds is under the control of "the song system" (a collection of interconnected forebrain nuclei dedicated to the learning and production of song), it might be expected that beak movements during singing would also be controlled by this system. However, direct neural connections between the telencephalic output of the song system and beak muscle motor neurons in the brainstem are conspicuous by their absence, leaving unresolved the question of how beak movements are affected during singing. By using standard tract tracing methods, we sought to answer this question by defining beak premotor neurons and examining their afferent projections. In the caudal medulla, jaw premotor cell bodies were located adjacent to the terminal field of the output of the song system, into which many premotor neurons extended their dendrites. The premotor neurons also received a novel input from the trigeminal ganglion and an overlapping input from a lateral arcopallial component of a trigeminal sensorimotor circuit that traverses the forebrain. The ganglionic input in songbirds, which is not present in doves and pigeons that vocalize with a closed beak, may modulate the activity of beak premotor neurons in concert with the output of the song system. These inputs to jaw premotor neurons could, together, affect beak movements as a means of modulating filter properties of the upper vocal tract during singing.
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Affiliation(s)
- J M Wild
- Department of Anatomy, Faculty of Medical and Health Science, University of Auckland, Auckland 1142, New Zealand.
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Méndez JM, Mindlin GB, Goller F. Interaction between telencephalic signals and respiratory dynamics in songbirds. J Neurophysiol 2012; 107:2971-83. [PMID: 22402649 DOI: 10.1152/jn.00646.2011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanisms by which telencephalic areas affect motor activities are largely unknown. They could either take over motor control from downstream motor circuits or interact with the intrinsic dynamics of these circuits. Both models have been proposed for telencephalic control of respiration during learned vocal behavior in birds. The interactive model postulates that simple signals from the telencephalic song control areas are sufficient to drive the nonlinear respiratory network into producing complex temporal sequences. We tested this basic assumption by electrically stimulating telencephalic song control areas and analyzing the resulting respiratory patterns in zebra finches and in canaries. We found strong evidence for interaction between the rhythm of stimulation and the intrinsic respiratory rhythm, including naturally emerging subharmonic behavior and integration of lateralized telencephalic input. The evidence for clear interaction in our experimental paradigm suggests that telencephalic vocal control also uses a similar mechanism. Furthermore, species differences in the response of the respiratory system to stimulation show parallels to differences in the respiratory patterns of song, suggesting that the interactive production of respiratory rhythms is manifested in species-specific specialization of the involved circuitry.
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Affiliation(s)
- Jorge M Méndez
- Dept. of Biology, Univ. of Utah, Salt Lake City, UT 84112, USA
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Tobari Y, Okumura T, Tani J, Okanoya K. A direct neuronal connection between the telencephalic nucleus robustus arcopallialis and the nucleus nervi hypoglossi, pars tracheosyringealis in Bengalese finches (Lonchura striata var. domestica). Neurosci Res 2011; 71:361-8. [PMID: 21945522 DOI: 10.1016/j.neures.2011.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 09/09/2011] [Accepted: 09/12/2011] [Indexed: 10/17/2022]
Abstract
Bird species with vocal learning possess a projection from the telencephalic nucleus to the nucleus nervi hypoglossi, pars tracheosyringealis (XIIts) in the medulla, where a final common pathway that controls the vocal organ, i.e., the synrinx, originates. The anatomical basis of this projection has not been well investigated in one species of songbird, the Bengalese finch (Lonchura striata var. domestica). The present study used anterograde and retrograde tracing experiments to examine and describe this projection in Bengalese finches. Following iontophoretic injections of biotinylated dextran amine into the telencephalic nucleus robustus arcopallialis (RA), we detected anterograde-labeled terminations in the XIIts. In addition, labeled terminals were seen in other vocal-respiratory-related nuclei, such as the dorsomedial nucleus of the nucleus intercollicularis, nucleus infraolivaris superior, nucleus of the rostral ventrolateral medulla, nucleus parambigualis, nucleus ambiguous, and nucleus retroambigualis. Furthermore, following injections into the XIIts, we detected retrograde-labeled cell bodies scattered throughout the ipsilateral RA. The present results revealed that the direct projections of the RA to the XIIts in male Bengalese finches are similar to those in other songbirds with vocal learning abilities.
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Affiliation(s)
- Yasuko Tobari
- Laboratory for Biolinguistics, RIKEN Brain Science Institute (RIKEN-BSI), Hirosawa, Wako-shi, Saitama 351-0198, Japan
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Andalman AS, Foerster JN, Fee MS. Control of vocal and respiratory patterns in birdsong: dissection of forebrain and brainstem mechanisms using temperature. PLoS One 2011; 6:e25461. [PMID: 21980466 PMCID: PMC3182229 DOI: 10.1371/journal.pone.0025461] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 09/05/2011] [Indexed: 11/20/2022] Open
Abstract
Learned motor behaviors require descending forebrain control to be coordinated with midbrain and brainstem motor systems. In songbirds, such as the zebra finch, regular breathing is controlled by brainstem centers, but when the adult songbird begins to sing, its breathing becomes tightly coordinated with forebrain-controlled vocalizations. The periods of silence (gaps) between song syllables are typically filled with brief breaths, allowing the bird to sing uninterrupted for many seconds. While substantial progress has been made in identifying the brain areas and pathways involved in vocal and respiratory control, it is not understood how respiratory and vocal control is coordinated by forebrain motor circuits. Here we combine a recently developed technique for localized brain cooling, together with recordings of thoracic air sac pressure, to examine the role of cortical premotor nucleus HVC (proper name) in respiratory-vocal coordination. We found that HVC cooling, in addition to slowing all song timescales as previously reported, also increased the duration of expiratory pulses (EPs) and inspiratory pulses (IPs). Expiratory pulses, like song syllables, were stretched uniformly by HVC cooling, but most inspiratory pulses exhibited non-uniform stretch of pressure waveform such that the majority of stretch occurred late in the IP. Indeed, some IPs appeared to change duration by the earlier or later truncation of an underlying inspiratory event. These findings are consistent with the idea that during singing the temporal structure of EPs is under the direct control of forebrain circuits, whereas that of IPs can be strongly influenced by circuits downstream of HVC, likely in the brainstem. An analysis of the temporal jitter of respiratory and vocal structure suggests that IPs may be initiated by HVC at the end of each syllable and terminated by HVC immediately before the onset of the next syllable.
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Affiliation(s)
- Aaron S. Andalman
- McGovern Institute for Brain Research, Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Jakob N. Foerster
- McGovern Institute for Brain Research, Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Michale S. Fee
- McGovern Institute for Brain Research, Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail:
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Veit L, Aronov D, Fee MS. Learning to breathe and sing: development of respiratory-vocal coordination in young songbirds. J Neurophysiol 2011; 106:1747-65. [PMID: 21697438 DOI: 10.1152/jn.00247.2011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
How do animals with learned vocalizations coordinate vocal production with respiration? Songbirds such as the zebra finch learn their songs, beginning with highly variable babbling vocalizations known as subsong. After several weeks of practice, zebra finches are able to produce a precisely timed pattern of syllables and silences, precisely coordinated with expiratory and inspiratory pulses (Franz M, Goller F. J Neurobiol 51: 129-141, 2002). While respiration in adult song is well described, relatively little is known about respiratory patterns in subsong or about the processes by which respiratory and vocal patterns become coordinated. To address these questions, we recorded thoracic air sac pressure in juvenile zebra finches prior to the appearance of any consistent temporal or acoustic structure in their songs. We found that subsong contains brief inspiratory pulses (50 ms) alternating with longer pulses of sustained expiratory pressure (50-500 ms). In striking contrast to adult song, expiratory pulses often contained multiple (0-8) variably timed syllables separated by expiratory gaps and were only partially vocalized. During development, expiratory pulses became shorter and more stereotyped in duration with shorter and fewer nonvocalized parts. These developmental changes eventually resulted in the production of a single syllable per expiratory pulse and a single inspiratory pulse filling each gap, forming a coordinated sequence similar to that of adult song. To examine the role of forebrain song-control nuclei in the development of respiratory patterns, we performed pressure recordings before and after lesions of nucleus HVC (proper name) and found that this manipulation reverses the developmental trends in measures of the respiratory pattern.
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Affiliation(s)
- Lena Veit
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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Chagnaud BP, Baker R, Bass AH. Vocalization frequency and duration are coded in separate hindbrain nuclei. Nat Commun 2011; 2:346. [PMID: 21673667 PMCID: PMC3166519 DOI: 10.1038/ncomms1349] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 05/11/2011] [Indexed: 01/07/2023] Open
Abstract
Temporal patterning is an essential feature of neural networks producing precisely timed behaviours such as vocalizations that are widely used in vertebrate social communication. Here we show that intrinsic and network properties of separate hindbrain neuronal populations encode the natural call attributes of frequency and duration in vocal fish. Intracellular structure/function analyses indicate that call duration is encoded by a sustained membrane depolarization in vocal prepacemaker neurons that innervate downstream pacemaker neurons. Pacemaker neurons, in turn, encode call frequency by rhythmic, ultrafast oscillations in their membrane potential. Pharmacological manipulations show prepacemaker activity to be independent of pacemaker function, thus accounting for natural variation in duration which is the predominant feature distinguishing call types. Prepacemaker neurons also innervate key hindbrain auditory nuclei thereby effectively serving as a call-duration corollary discharge. We propose that premotor compartmentalization of neurons coding distinct acoustic attributes is a fundamental trait of hindbrain vocal pattern generators among vertebrates.
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Affiliation(s)
- Boris P Chagnaud
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853, USA
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19
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Brainstem vocalization area in guinea pigs. Neurosci Res 2009; 66:359-65. [PMID: 20025909 DOI: 10.1016/j.neures.2009.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 12/07/2009] [Accepted: 12/09/2009] [Indexed: 11/22/2022]
Abstract
The purpose of the present study was to determine whether murines could be substituted for traditional experimental mammals to study the brainstem mechanism of vocalization. We conducted systematic electrical and chemical stimulation of the brainstem in guinea pigs to identify the similarities in the call sites between murines and other mammals. We further examined whether or not fictive vocalization could be induced in paralyzed guinea pigs, an experimental model which facilitates neuronal recording in the brainstem. The sites where electrical stimulation evoked vocalization were distributed continuously from the periaqueductal grey (PAG) to the lower brainstem. This call area usually ended at the most caudal part of the inferior olive and thus did not continuously extend to the nucleus retroambiguus. Microinjections of d,l-homocysteic acid and bicuculline induced vocalization at the PAG, parabrachial nucleus, and the most dorsal part of the pontine reticular formation. The brainstem call areas and vocal motor patterns induced from these areas were approximately consistent with those in other mammals. Fictive vocalization induced by PAG stimulation could be identified from activities of the phrenic, abdominal, and superior laryngeal nerves in paralyzed guinea pigs. We thus concluded that guinea pigs can be utilized in studies of brainstem vocal mechanism.
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Wild JM, Kubke MF, Mooney R. Avian nucleus retroambigualis: cell types and projections to other respiratory-vocal nuclei in the brain of the zebra finch (Taeniopygia guttata). J Comp Neurol 2009; 512:768-83. [PMID: 19067354 DOI: 10.1002/cne.21932] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In songbirds song production requires the intricate coordination of vocal and respiratory muscles under the executive influence of the telencephalon, as for speech in humans. In songbirds the site of this coordination is suspected to be the nucleus retroambigualis (RAm), because it contains premotor neurons projecting upon both vocal motoneurons and spinal motoneurons innervating expiratory muscles, and because it receives descending inputs from the telencephalic vocal control nucleus robustus archopallialis (RA). Here we used tract-tracing techniques to provide a more comprehensive account of the projections of RAm and to identify the different populations of RAm neurons. We found that RAm comprises diverse projection neuron types, including: 1) bulbospinal neurons that project, primarily contralaterally, upon expiratory motoneurons; 2) a separate group of neurons that project, primarily ipsilaterally, upon vocal motoneurons in the tracheosyringeal part of the hypoglossal nucleus (XIIts); 3) neurons that project throughout the ipsilateral and contralateral RAm; 4) another group that sends reciprocal, ascending projections to all the brainstem sources of afferents to RAm, namely, nucleus parambigualis, the ventrolateral nucleus of the rostral medulla, nucleus infra-olivarus superior, ventrolateral parabrachial nucleus, and dorsomedial nucleus of the intercollicular complex; and 5) a group of relatively large neurons that project their axons into the vagus nerve. Three morphological classes of RAm cells were identified by intracellular labeling, the dendritic arbors of which were confined to RAm, as defined by the terminal field of RA axons. Together the ascending and descending projections of RAm confirm its pivotal role in the mediation of respiratory-vocal control.
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Affiliation(s)
- J M Wild
- Department of Anatomy, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
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Bass AH, Gilland EH, Baker R. Evolutionary origins for social vocalization in a vertebrate hindbrain-spinal compartment. Science 2008; 321:417-21. [PMID: 18635807 DOI: 10.1126/science.1157632] [Citation(s) in RCA: 170] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The macroevolutionary events leading to neural innovations for social communication, such as vocalization, are essentially unexplored. Many fish vocalize during female courtship and territorial defense, as do amphibians, birds, and mammals. Here, we map the neural circuitry for vocalization in larval fish and show that the vocal network develops in a segment-like region across the most caudal hindbrain and rostral spinal cord. Taxonomic analysis demonstrates a highly conserved pattern between fish and all major lineages of vocal tetrapods. We propose that the vocal basis for acoustic communication among vertebrates evolved from an ancestrally shared developmental compartment already present in the early fishes.
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Affiliation(s)
- Andrew H Bass
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA.
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Telencephalic neurons monosynaptically link brainstem and forebrain premotor networks necessary for song. J Neurosci 2008; 28:3479-89. [PMID: 18367614 DOI: 10.1523/jneurosci.0177-08.2008] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Birdsong, like human speech, is a series of learned vocal gestures resulting from the coordination of vocal and respiratory brainstem networks under the control of the telencephalon. The song motor circuit includes premotor and motor cortical analogs, known as HVC (used as a proper name) and RA (the robust nucleus of the arcopallium), respectively. Previous studies showed that HVC projects to RA and that RA projection neurons (PNs) topographically innervate brainstem vocal-motor and respiratory networks. The idea that singing-related activity flows between HVC and RA in a strictly feedforward manner is a central component of all models of song production. In contrast to this prevailing view of song motor circuit organization, we show that RA sends a reciprocal projection directly to HVC. Lentiviral labeling of RA PN axons and transgene tagging of RA PN synaptic terminals reveal a direct projection from RA to HVC. Retrograde tracing from HVC demonstrates that this projection originates exclusively from neurons in dorsocaudal regions of RA. Using dual retrograde tracer injections, we further show that many of these RA(HVC) neurons also innervate the brainstem nucleus retroambigualis, which is premotor to expiratory motoneurons, thereby identifying a population of RA PNs positioned to coordinate activity at higher and lower levels of the song motor circuit. In combination, our findings identify a previously unknown pathway that may enable a subset of RA neurons to provide song-related signals to the respiratory brainstem but also transmit a copy of this information to song patterning networks in HVC.
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Abstract
Brainstem motor structures send output commands to the periphery and are dynamically modulated by telencephalic inputs. Little is known, however, about ascending brainstem control of forebrain motor structures. Here, we provide the first evidence for bottom-up activation of forebrain motor centers by the respiratory brainstem. We show that, in the avian vocal control system, activation of the brainstem inspiratory nucleus paraambigualus (PAm), a likely homolog of the mammalian rostral ventral respiratory group, can drive neural activity bilaterally in the forebrain vocal control nuclei HVC (used as a proper name) and the robust nucleus of the arcopallium (RA). Furthermore, this activation is abolished by lesions of nucleus uvaeformis (Uva), a thalamic nucleus necessary for song production. We identify a type of bursting neuron within PAm whose activity is correlated, in an Uva dependent manner, to bursting activity in RA, rather than to the respiratory rhythm, and is robustly active during the production of stimulus evoked vocalizations. Because this ascending input results in cross-hemisphere activation, our results suggest a crucial role for the respiratory brainstem in coordinating forebrain motor centers during vocal production.
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Roberts TF, Wild JM, Kubke MF, Mooney R. Homogeneity of intrinsic properties of sexually dimorphic vocal motoneurons in male and female zebra finches. J Comp Neurol 2007; 502:157-69. [PMID: 17335045 DOI: 10.1002/cne.21310] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Sex differences in behavioral repertoires are often reflected in the underlying electrophysiological and morphological properties of motor neurons. Male zebra finches produce long, spectrally complex, learned songs and short calls, whereas female finches only produce short, innate, and spectrally simple calls. In both sexes, vocalizations are produced by using syringeal muscles controlled by motoneurons within the tracheosyringeal part of the hypoglossal motor nucleus (XIIts). We asked whether the sexually dimorphic vocal repertoire of adult zebra finches is paralleled by structural and functional differences in syringeal motoneurons. By using immunohistochemical and intracellular staining methods, we describe sex differences in the morphology of XIIts and its surrounding neuropil (suprahypoglossal region; SH). Although the overall number of XIIts neurons and the proportions of somata/neuropil were not sexually dimorphic, the volumes of both XIIts and SH were larger in males, in part because male XIIts neurons had larger somata. In contrast, female XIIts motoneurons had a more complex dendritic structure than did male neurons, suggesting that the larger volume of the male XIIts is due in part to increased numbers of afferents. Intracellular recordings in brain slices revealed that the intrinsic electrophysiological properties of female XIIts neurons were similar to published values for male XIIts motoneurons. We also show that female neurons received glycinergic inputs from the brainstem respiratory premotor column, similar to those described in males. These findings indicate that male and female zebra finches produce their disparate vocal repertoires using physiologically similar motoneurons. Thus, sites upstream of the motoneuron pool may be the major determinants of sexually dimorphic vocal behaviors in this species.
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Affiliation(s)
- Todd F Roberts
- Department of Neurobiology, Duke University Medical Center, Durham North Carolina 27710, USA
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Smotherman M, Kobayasi K, Ma J, Zhang S, Metzner W. A mechanism for vocal-respiratory coupling in the mammalian parabrachial nucleus. J Neurosci 2006; 26:4860-9. [PMID: 16672660 PMCID: PMC6674146 DOI: 10.1523/jneurosci.4607-05.2006] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Mammalian vocalizations require the precise coordination of separate laryngeal and respiratory motor pathways. Precisely how and where in the brain vocal motor patterns interact with respiratory rhythm control is unknown. The parabrachial nucleus (PB) is known to mediate key respiratory reflexes and is also considered a principle component of the mammalian vocal motor pathway, making it a likely site for vocal-respiratory interactions, yet a specific role for the PB in vocalizing has yet to be demonstrated. To investigate the role of the PB in vocal-respiratory coordination, we pharmacologically manipulated synaptic activity in the PB while spontaneously vocalizing horseshoe bats were provoked to emit either short, single syllable or long, multisyllabic vocal motor patterns. Iontophoresis of the GABAA agonist muscimol (MUS) into the lateral PB extended expiratory durations surrounding all vocalizations and increased mean call durations. Alternatively, application of the GABAA antagonist bicuculline methiodide (BIC) shortened expirations and call durations. In addition, BIC eliminated the occurrence of multisyllabic vocalizations. BIC caused a mild increase in quiet breathing rates, whereas MUS tended to slow quiet breathing. The results indicate that GABAA receptor-mediated inhibition in the lateral PB modulates the time course of respiratory phase switching during vocalizing, and is needed for proper coordination of calling and breathing in mammals. We hypothesize that vocal-respiratory rhythm entrainment is achieved at least in part via mechanisms similar to other forms of locomotor-respiratory coupling, namely somatosensory feedback influences on respiratory phase-switching in the lateral PB.
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Affiliation(s)
- Michael Smotherman
- Department of Physiological Science, University of California, Los Angeles, California 90095, USA.
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