Miguel Maravall
Wednesday 12th March 2014
Time: 4pm
Basement Seminar Room
Alexandra House, 17 Queen Square, London, WC1N 3AR
“(Dis)organising principles for neuronal response properties in the whisker system”
In this talk I will argue that the functional architecture of the rodent whisker system, a popular model for plasticity and active sensing, displays several principles shared with other sensory modalities. At each stage of the whisker pathway, individual neurons are selective to distinct temporal features (receptive fields) and display variable adaptive behaviour; these heterogeneous properties at the single-neuron level result in robust, overcomplete representations of dynamic stimuli at the population level. We have found that, in superficial layers of mouse barrel cortex, the spatial distribution of neuronal selectivity for temporal features does not appear to follow any ordering scheme: instead, neurons with different preferred features are interspersed in space. The dynamics of synapses relaying whisker information from thalamus to cortex are similarly diverse. In sum, circuits in the whisker system implement canonical computations such as linear filtering and adaptive gain rescaling, and the diversity of neuronal and synaptic functional properties at each stage is likely to enable the construction of rich combinatorial codes for dynamic whisker stimuli.
A new review covering much of this work is: Maravall M & Diamond ME (2014). Algorithms of whisker-mediated touch perception. Curr Opin Neurobiol 25: 176-186. http://dx.doi.org/10.1016/j.conb.2014.01.014
Miguel Maravall is a principal investigator with the Spanish National Research Council, based at the Instituto de Neurociencias in Alicante. He trained for a PhD in Physics at SUNY Stony Brook and then carried out postdoctoral research in Karel Svoboda’s lab at Cold Spring Harbor Laboratory (1999-2002) and Mathew Diamond’s lab at SISSA (Trieste, 2002-2004) before starting his own group in Alicante. His lab’s research concerns information processing in sensory systems, using the rodent whisker system as a model. Work combines electrophysiology, imaging and analysis techniques to extract the signals contained in neuronal activity in vivo and in vitro.