Neuronal dynamics underlying self-generated behaviours in zebrafish larvae

SEBASTIÁN A. ROMANO; THOMAS PIETRI; GERMÁN SUMBRE

Lisboa

Simposio; Champalimaud Neuroscience Symposium; 2011

In a state of sensory deprivation, brain areas show activity patterns. Once interpreted as irrelevant random noise, these activities have been found to exhibit highly coherent spatiotemporal structures that could resemble patterns observed during neuronal processing of sensory stimuli. However, the relationship between ongoing neuronal activity and self-generated behaviours still remains elusive. To address this issue, we are currently filming spontaneous tail movements of head-restrained zebrafish larvae while monitoring brain activities using two-photon imaging of both calcium sensitive dyes and genetically encoded indicators. This method allows recording the dynamics of large neuronal circuits, with single-cell resolution, from several brain areas. We are applying dimensionality reduction techniques and clustering analysis to describe the network dynamics and the flow of activity among neuronal ensembles that best correlate with self-generated motor behaviours. Preliminary results indicate a clear structure in the ongoing neuronal activity of the optic tectum that follows its retinotopic organization, arguing for its possible behavioural relevance. Moreover, the activation of determined neuronal ensembles seems to be correlated with the kinematics of specific self-generated motor behaviours. Distinct behavioural states seem evident, and the neuronal substrate for this behavioural switching is currently under study.