Motor actions

The nervous system is fundamentally a closed loop control device: the output of actions continually influences the internal state and subsequent actions. This is true at the single cell and even the molecular level, where “actions” take the form of signals that are fed back to achieve a variety of functions, including homeostasis, excitability and various kinds of multistability that allow switching and storage of memory. It is also true at the behavioural level, where an animal’s motor actions directly influence sensory input on short timescales, and higher level information about goals and i

Understanding how neural circuits generate sequential activity is a longstanding challenge. While theoretical models have previously demonstrated how sequences can be stored as memories with Hebbian plasticity rules, these models considered only a particular Hebbian rule that is not observed in experiments. Here we consider a recently introduced model for arbitrary Hebbian plasticity rules and show how the choice of these rules and of the neural activity patterns influences memorized sequence retrieval. In particular, we derive a general theory that predicts the speed of sequence traversal. Th

Animals control motor actions at multiple timescales. We use larval zebrafish and advanced optical microscopy to understand the underlying neural mechanisms. First, we examined the mechanisms of short-term motor learning by using whole-brain neural activity imaging. We found that the 5-HT system integrates the sensory outcome of actions and determines future motor patterns. Second, we established a method for recording spiking activity and membrane potential from a population of neurons during behavior. We identified putative motor command signals and internal copy signals that encode millisec