Call initiation in African clawed frogs

PosterSociety for Neuroscience Meeting 201

Neurocircuitry underlying vocal production of the African clawed frog, Xenopus laevis

posterThis poster describes how motor and premotor neurons are interconnected to each other using electrophysiological and pharmacological techniques

Development of techniques to deliver transgenes into neurons of amphibians

PosterSociety for Neuroscience Meeting 201

Coding rate and duration of vocalizations of the frog , Xenopus laevis

Journal ArticleVocalizations 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 sub-threshold oscillations and action potentials at fast-trill rates, indicating FTN resonance properties are tuned to, and may dictate, the fast-trill rhythm. NMDAreceptor(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

Bilateral coordination of vocal pathways in African clawed frogs, Xenopus laevis

posterThis poster describes how bilateral coordination of motor programs are achieved in the central vocal pathways of African clawed frogs

Speech-related gene foxp2 expression in the central vocal pathways of the African clawed frogs

PosterSociety for Neuroscience Meeting 201

Rhythm generation, coordination, and initiation in the vocal pathways of male African clawed frogs

Poste

Development of an acute method to deliver transgenes into the brains of adult Xenopus laevis

journal articleThe central vocal pathway of the African clawed frog, Xenopus laevis, is a powerful vertebrate model to understand mechanisms underlying central pattern generation. However, fast and efficient methods of introducing exogenous genes into the neurons of adult X. laevis are currently not available. Here, we systematically tested methods of transgene delivery into adult X. laevis neurons. Although successfully used for tadpole neurons for over a decade, electroporation was not efficient in transfecting adult neurons. Similarly, adeno-associated virus (AAV) was not reliable, and lentivirus (LV) failed to function as viral vector in adult Xenopus neurons. In contrast, vesicular stomatitis virus (VSV) was a fast and robust vector for adult X. laevis neurons

Distinct neural control of vocal phases in frog calls

posterThis poster describes how the connections within the central vocal pathways of African clawed frogs are responsible for coordinating distinct part of their calls

コウチ ホウゲン ニオケル ヨツガナ タイケイ ノ ドウタイ

Yotsugana, four types [зi dзi zu dzu] of Kana, used to be pronounced one another differently in the old Japanese. In modern Japanese, зi and dзi, zu and dzu had merged together each other, four kinds of pronunciation as a result becomes two. But in the Kouchi dialects these four different pronunciation has been maintained. We investigated Kouchi dialects to know how much its difference still remains. We aim to clarify the regional and generational difference in the usage of Yotsugana in the Kouchi prefecture