Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
???displayArticle.abstract???
Many rhythmic behaviors, such as locomotion and vocalization, involve temporally dynamic patterns. How does the brain generate temporal complexity? Here, we use the vocal central pattern generator (CPG) of Xenopus laevis to address this question. Isolated brains can elicit fictive vocalizations, allowing us to study the CPG in vitro. The X. laevis advertisement call is temporally modulated; calls consist of rhythmic click trills that alternate between fast (approximately 60 Hz) and slow (approximately 30 Hz) rates. We investigated the role of two CPG nuclei--the laryngeal motor nucleus (n.IX-X) and the dorsal tegmental area of the medulla (DTAM)--in setting rhythm frequency and call durations. We discovered a local field potential wave in DTAM that coincides with fictive fast trills and phasic activity that coincides with fictive clicks. After disrupting n.IX-X connections, the wave persists, whereas phasic activity disappears. Wave duration was temperature dependent and correlated with fictive fast trills. This correlation persisted when wave duration was modified by temperature manipulations. Selectively cooling DTAM, but not n.IX-X, lengthened fictive call and fast trill durations, whereas cooling either nucleus decelerated the fictive click rate. The N-methyl-d-aspartate receptor (NMDAR) antagonist dAPV blocked waves and fictive fast trills, suggesting that the wave controls fast trill activation and, consequently, call duration. We conclude that two functionally distinct CPG circuits exist: 1) a pattern generator in DTAM that determines call duration and 2) a rhythm generator (spanning DTAM and n.IX-X) that determines click rates. The newly identified DTAM pattern generator provides an excellent model for understanding NDMAR-dependent rhythmic circuits.
Brahic,
Vocal circuitry in Xenopus laevis: telencephalon to laryngeal motor neurons.
2003, Pubmed,
Xenbase
Brahic,
Vocal circuitry in Xenopus laevis: telencephalon to laryngeal motor neurons.
2003,
Pubmed
,
Xenbase
Collingridge,
Frequency-dependent N-methyl-D-aspartate receptor-mediated synaptic transmission in rat hippocampus.
1988,
Pubmed
Cowley,
A comparison of motor patterns induced by N-methyl-D-aspartate, acetylcholine and serotonin in the in vitro neonatal rat spinal cord.
1994,
Pubmed
Daw,
The role of NMDA receptors in information processing.
1993,
Pubmed
Di Prisco,
Role of sensory-evoked NMDA plateau potentials in the initiation of locomotion.
1997,
Pubmed
Foutz,
Involvement of N-methyl-D-aspartate (NMDA) receptors in respiratory rhythmogenesis.
1989,
Pubmed
Grillner,
Activation of NMDA-receptors elicits "fictive locomotion" in lamprey spinal cord in vitro.
1981,
Pubmed
Haji,
N-methyl-D-aspartate mechanisms in depolarization of augmenting expiratory neurons during the expulsive phase of fictive cough in decerebrate cats.
2008,
Pubmed
Hochman,
N-methyl-D-aspartate receptor-mediated voltage oscillations in neurons surrounding the central canal in slices of rat spinal cord.
1994,
Pubmed
Janssen,
Thermal influences on nervous system function.
1992,
Pubmed
Jürgens,
Neural pathways underlying vocal control.
2002,
Pubmed
Kelley,
Auditory and vocal nuclei in the frog brain concentrate sex hormones.
1980,
Pubmed
,
Xenbase
Monaghan,
Distribution of N-methyl-D-aspartate-sensitive L-[3H]glutamate-binding sites in rat brain.
1985,
Pubmed
Mörschel,
Pontine respiratory activity involved in inspiratory/expiratory phase transition.
2009,
Pubmed
Pierrefiche,
Nitric oxide and respiratory rhythm in mammals: a new modulator of phase transition?
2007,
Pubmed
Potts,
Respiratory rhythm entrainment by somatic afferent stimulation.
2005,
Pubmed
Prime,
N-Methyl-D-aspartate-induced oscillations in whole cell clamped neurons from the isolated spinal cord of Xenopus laevis embryos.
1999,
Pubmed
,
Xenbase
Rhodes,
Xenopus vocalizations are controlled by a sexually differentiated hindbrain central pattern generator.
2007,
Pubmed
,
Xenbase
Schmidt,
Neural correlates of frog calling: production by two semi-independent generators.
1992,
Pubmed
Simpson,
Origin and identification of fibers in the cranial nerve IX-X complex of Xenopus laevis: Lucifer Yellow backfills in vitro.
1986,
Pubmed
,
Xenbase
Smith,
Characterisation of inhibitory and excitatory postsynaptic currents of the rat medial superior olive.
2000,
Pubmed
Smotherman,
A mechanism for vocal-respiratory coupling in the mammalian parabrachial nucleus.
2006,
Pubmed
Tobias,
Vocal communication between male Xenopus laevis.
2004,
Pubmed
,
Xenbase
Tobias,
Rapping, a female receptive call, initiates male-female duets in the South African clawed frog.
1998,
Pubmed
,
Xenbase
Tresch,
Motor coordination without action potentials in the mammalian spinal cord.
2000,
Pubmed
Tunstall,
Longitudinal coordination of motor output during swimming in Xenopus embryos.
1991,
Pubmed
,
Xenbase
von Euler,
Excitability changes of the inspiratory "off-switch" mechanism tested by electrical stimulation in nucleus parabrachialis in the cat.
1976,
Pubmed
Wallén,
N-methyl-D-aspartate receptor-induced, inherent oscillatory activity in neurons active during fictive locomotion in the lamprey.
1987,
Pubmed
Wetzel,
Androgen and gonadotropin effects on male mate calls in South African clawed frogs, Xenopus laevis.
1983,
Pubmed
,
Xenbase
Wetzel,
A proposed neural pathway for vocalization in South African clawed frogs, Xenopus laevis.
1985,
Pubmed
,
Xenbase
Yamaguchi,
Temperature-dependent regulation of vocal pattern generator.
2008,
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,
Regulation of respiratory and vocal motor pools in the isolated brain of Xenopus laevis.
2008,
Pubmed
,
Xenbase
