Louis Saint-Amant

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The development and properties of locomotor behaviors in zebrafish embryos raised at 28.5 degrees C were examined. When freed from the chorion, embryonic zebrafish showed three sequential stereotyped behaviors: a transient period of alternating, coiling contractions followed by touch-evoked rapid coils, then finally, organized swimming. The three different(More)
The zebrafish is a popular model for developmental studies due to its accessibility by cellular, molecular and genetic approaches. As a complement to these other methods, we have devised an exposed hindbrain/spinal cord preparation in the curarized zebrafish embryo and larva that permits intracellular labeling and patch clamp recording from individually(More)
As a first step in the study of the developing motor circuitry of the embryonic zebrafish spinal cord, we obtained patch-clamp recordings in vivo from identified motoneurons in curarized embryos from the onset of the first motor behavior. At an early developmental stage in which embryos showed slow and repetitive spontaneous contractions of the trunk,(More)
Zinc has been reported to potentiate glycine receptors (GlyR), but the physiological significance of this observation has been put in doubt by the relatively high values of the EC(50), 0.5-1 microM, since such concentrations may not be attained in the synaptic cleft of glycinergic synapses. We have re-evaluated this observation in the frame of the(More)
This review summarizes recent data from our lab concerning the development of motor activities in the developing zebrafish. The zebrafish is a leading model for studies of vertebrate development because one can obtain a large number of transparent, externally and rapidly developing embryos with motor behaviors that are easy to assess (e.g. for mutagenic(More)
Characterizing connectivity in the spinal cord of zebrafish embryos is not only prerequisite to understanding the development of locomotion, but is also necessary for maximizing the potential of genetic studies of circuit formation in this model system. During their first day of development, zebrafish embryos show two simple motor behaviors. First, they(More)
Bilateral alternation of muscle contractions requires reciprocal inhibition between the two sides of the hindbrain and spinal cord, and disruption of this inhibition should lead to simultaneous activation of bilateral muscles. At 1 day after fertilization, wild-type zebrafish respond to mechanosensory stimulation with multiple fast alternating trunk(More)
There is a need to understand the mechanisms of neural synchronization during development because correlated rhythmic activity is thought to be critical for the establishment of proper connectivity. The relative importance of chemical and electrical synapses for synchronization of electrical activity during development is unclear. We examined the activity(More)
The zebrafish is a leading model for studies of vertebrate development and genetics. Its embryonic motor behaviors are easy to assess (e.g. for mutagenic screens), the embryos develop rapidly (hatching as larvae at 2 days) and are transparent, permitting calcium imaging and patch clamp recording in vivo. We review primarily the recent advances in(More)
Excitation-contraction coupling, the process that regulates contractions by skeletal muscles, transduces changes in membrane voltage by activating release of Ca(2+) from internal stores to initiate muscle contraction. Defects in excitation-contraction coupling are associated with muscle diseases. Here we identify Stac3 as a novel component of the(More)