The dynamics of the ongoing spontaneous neuronal activity in zebrafish larvae

SEBASTIAN A. ROMANO; THOMAS PIETRI; VERONICA PEREZ SCHUSTER; GERMAN SUMBRE

Nueva Orleans

Congreso; SfN's 42nd annual meeting; 2012

SFN

In a state of sensory deprivation, sensory brain areas remain active. Once interpreted as irrelevant random noise, these activities have been found to exhibit coarse spatiotemporal structures, however, the biological significance of this ongoing neuronal activity still remains elusive. To address this issue, we are currently monitoring brain activities of head-restrained zebrafish larvae, using two-photon imaging of genetically encoded calcium indicators (GCaMP3). This method allows recording the dynamics of large neuronal circuits, with single-cell resolution, from several brain areas of an intact behaving vertebrate. We are applying dimensionality reduction techniques and clustering analysis to describe circuit dynamics. Our results demonstrate that the optic tectum, a brain region homolog to the mammalian superior colliculus and the largest visual center of the zebrafish, presents a precise spatiotemporal structure in its ongoing population activity and that this process seems to be driven by local recurrent circuitry. Moreover, these patterns resemble, at the single-cell level, functional visual maps, arguing for their biological significance.