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UNLABELLED: Central pattern generators (CPGs) in the brain stem are considered to underlie vocalizations in many vertebrate species, but the detailed mechanisms underlying how motor rhythms are generated, coordinated, and initiated remain unclear. We addressed these issues using isolated brain preparations of Xenopus laevis from which fictive vocalizations can be elicited. Advertisement calls of male X. laevis that consist of fast and slow trills are generated by vocal CPGs contained in the brain stem. Brain stem central vocal pathways consist of a premotor nucleus [dorsal tegmental area of medulla (DTAM)] and a laryngeal motor nucleus [a homologue of nucleus ambiguus (n.IX-X)] with extensive reciprocal connections between the nuclei. In addition, DTAM receives descending inputs from the extended amygdala. We found that unilateral transection of the projections between DTAM and n.IX-X eliminated premotor fictive fast trill patterns but did not affect fictive slow trills, suggesting that the fast and slow trill CPGs are distinct; the slow trill CPG is contained in n.IX-X, and the fast trill CPG spans DTAM and n.IX-X. Midline transections that eliminated the anterior, posterior, or both commissures caused no change in the temporal structure of fictive calls, but bilateral synchrony was lost, indicating that the vocal CPGs are contained in the lateral halves of the brain stem and that the commissures synchronize the two oscillators. Furthermore, the elimination of the inputs from extended amygdala to DTAM, in addition to the anterior commissure, resulted in autonomous initiation of fictive fast but not slow trills by each hemibrain stem, indicating that the extended amygdala provides a bilateral signal to initiate fast trills.
NEW & NOTEWORTHY: Central pattern generators (CPGs) are considered to underlie vocalizations in many vertebrate species, but the detailed mechanisms underlying their functions remain unclear. We addressed this question using an isolated brain preparation of African clawed frogs. We discovered that two vocal phases are mediated by anatomically distinct CPGs, that there are a pair of CPGs contained in the left and right half of the brain stem, and that mechanisms underlying initiation of the two vocal phases are distinct.
Albersheim-Carter,
Testing the evolutionary conservation of vocal motoneurons in vertebrates.
2016, Pubmed
Albersheim-Carter,
Testing the evolutionary conservation of vocal motoneurons in vertebrates.
2016,
Pubmed Bass,
Evolutionary origins for social vocalization in a vertebrate hindbrain-spinal compartment.
2008,
Pubmed Berkowitz,
Multifunctional and specialized spinal interneurons for turtle limb movements.
2010,
Pubmed Briggman,
Imaging dedicated and multifunctional neural circuits generating distinct behaviors.
2006,
Pubmed Brown,
On the nature of the fundamental activity of the nervous centres; together with an analysis of the conditioning of rhythmic activity in progression, and a theory of the evolution of function in the nervous system.
1914,
Pubmed Buchanan,
Flexibility in the patterning and control of axial locomotor networks in lamprey.
2011,
Pubmed Cangiano,
Fast and slow locomotor burst generation in the hemispinal cord of the lamprey.
2003,
Pubmed Cangiano,
The hemisegmental locomotor network revisited.
2012,
Pubmed Chagnaud,
Vocalization frequency and duration are coded in separate hindbrain nuclei.
2011,
Pubmed Cohen,
Strychnine eliminates alternating motor output during fictive locomotion in the lamprey.
1984,
Pubmed Cowley,
Effects of inhibitory amino acid antagonists on reciprocal inhibitory interactions during rhythmic motor activity in the in vitro neonatal rat spinal cord.
1995,
Pubmed Dickinson,
Neuropeptide fusion of two motor-pattern generator circuits.
1990,
Pubmed Evans,
Genetics, Morphology, Advertisement Calls, and Historical Records Distinguish Six New Polyploid Species of African Clawed Frog (Xenopus, Pipidae) from West and Central Africa.
2015,
Pubmed
,
Xenbase Fetcho,
Some principles of organization of spinal neurons underlying locomotion in zebrafish and their implications.
2010,
Pubmed Garcia,
Chapter 3--networks within networks: the neuronal control of breathing.
2011,
Pubmed Grillner,
Biological pattern generation: the cellular and computational logic of networks in motion.
2006,
Pubmed Hall,
The Xenopus amygdala mediates socially appropriate vocal communication signals.
2013,
Pubmed
,
Xenbase Hikosaka,
GABAergic output of the basal ganglia.
2007,
Pubmed Hinckley,
Distinct roles of glycinergic and GABAergic inhibition in coordinating locomotor-like rhythms in the neonatal mouse spinal cord.
2005,
Pubmed Hooper,
Switching of a neuron from one network to another by sensory-induced changes in membrane properties.
1989,
Pubmed Hooper,
Cellular and synaptic mechanisms responsible for a long-lasting restructuring of the lobster pyloric network.
1990,
Pubmed Jürgens,
On the role of the reticular formation in vocal pattern generation.
2007,
Pubmed Kiehn,
Probing spinal circuits controlling walking in mammals.
2010,
Pubmed Kwan,
Activity of Hb9 interneurons during fictive locomotion in mouse spinal cord.
2009,
Pubmed Leininger,
Species-specific loss of sexual dimorphism in vocal effectors accompanies vocal simplification in African clawed frogs (Xenopus).
2015,
Pubmed
,
Xenbase Li,
Selective Gating of Neuronal Activity by Intrinsic Properties in Distinct Motor Rhythms.
2015,
Pubmed
,
Xenbase Li,
Specific brainstem neurons switch each other into pacemaker mode to drive movement by activating NMDA receptors.
2010,
Pubmed
,
Xenbase Marder,
Principles of rhythmic motor pattern generation.
1996,
Pubmed Marder,
Central pattern generators and the control of rhythmic movements.
2001,
Pubmed Marder,
Invertebrate central pattern generation moves along.
2005,
Pubmed Meyrand,
Dynamic construction of a neural network from multiple pattern generators in the lobster stomatogastric nervous system.
1994,
Pubmed Meyrand,
Construction of a pattern-generating circuit with neurons of different networks.
1991,
Pubmed Mink,
The basal ganglia: focused selection and inhibition of competing motor programs.
1996,
Pubmed Moreno,
Characterization of the bed nucleus of the stria terminalis in the forebrain of anuran amphibians.
2012,
Pubmed
,
Xenbase Moreno,
Central amygdala in anuran amphibians: neurochemical organization and connectivity.
2005,
Pubmed
,
Xenbase Moult,
Fast silencing reveals a lost role for reciprocal inhibition in locomotion.
2013,
Pubmed
,
Xenbase Nambu,
Functional significance of the cortico-subthalamo-pallidal 'hyperdirect' pathway.
2002,
Pubmed Popescu,
Highly dissimilar behaviors mediated by a multifunctional network in the marine mollusk Tritonia diomedea.
2002,
Pubmed Potter,
Androgen-induced vocal transformation in adult female African clawed frogs.
2005,
Pubmed
,
Xenbase Rhodes,
Xenopus vocalizations are controlled by a sexually differentiated hindbrain central pattern generator.
2007,
Pubmed
,
Xenbase Roberts,
A functional scaffold of CNS neurons for the vertebrates: the developing Xenopus laevis spinal cord.
2012,
Pubmed
,
Xenbase Sakurai,
Two interconnected kernels of reciprocally inhibitory interneurons underlie alternating left-right swim motor pattern generation in the mollusk Melibe leonina.
2014,
Pubmed Satterlie,
Toward an organismal neurobiology: integrative neuroethology.
2013,
Pubmed Satterlie,
Reciprocal inhibition and postinhibitory rebound produce reverberation in a locomotor pattern generator.
1985,
Pubmed Schmidt,
Neural correlates of frog calling: production by two semi-independent generators.
1992,
Pubmed Sweeney,
Harnessing vocal patterns for social communication.
2014,
Pubmed
,
Xenbase Tobias,
Evolution of advertisement calls in African clawed frogs.
2011,
Pubmed
,
Xenbase Van Vreeswijk,
When inhibition not excitation synchronizes neural firing.
1994,
Pubmed Wang,
Spindle rhythmicity in the reticularis thalami nucleus: synchronization among mutually inhibitory neurons.
1993,
Pubmed Weimann,
Switching neurons are integral members of multiple oscillatory networks.
1994,
Pubmed Yamaguchi,
Generating sexually differentiated vocal patterns: laryngeal nerve and EMG recordings from vocalizing male and female african clawed frogs (Xenopus laevis).
2000,
Pubmed
,
Xenbase Yu,
5-HT2C-like receptors in the brain of Xenopus laevis initiate sex-typical fictive vocalizations.
2009,
Pubmed
,
Xenbase Yu,
Endogenous serotonin acts on 5-HT2C-like receptors in key vocal areas of the brain stem to initiate vocalizations in Xenopus laevis.
2010,
Pubmed
,
Xenbase Zornik,
Breathing and calling: neuronal networks in the Xenopus laevis hindbrain.
2007,
Pubmed
,
Xenbase Zornik,
A neuroendocrine basis for the hierarchical control of frog courtship vocalizations.
2011,
Pubmed
,
Xenbase Zornik,
NMDAR-dependent control of call duration in Xenopus laevis.
2010,
Pubmed
,
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