Neuronal Processing

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Professor Troy Margrie
Honorary Professor
Tel: +44 (0)20 7679 0979
Email: t.margrie@ucl.ac.uk
TMimage5 Troy Margrie biography

Information about the world around us is gathered by our sensory organs and relayed to the brain, where it is processed and integrated by large multimodal neuronal networks. Such stimulus-related network activity is thought to represent an organism's external world and underlie cognitive processing and the generation of motor output. Our major aim is to determine the ways in which synaptic potentials, oscillatory rhythms and plasticity interact to provide single cortical cells and networks of cells with the computational power that is required for processing the necessary information.

We use a multidisciplinary approach that combines genetic, electrophysiological, imaging and behavioural tools to examine the molecular basis of the integrative elements that are involved in processing at various levels of signalling pathway. By combining whole-cell recordings and imaging, both in vivo and in vitro, we are able to examine network properties - including synaptic transmission and dendritic integration - under physiologically relevant conditions. The spatiotemporal properties of stimulus-evoked activity determined from in vivo experiments are also: (i) used to direct in vitro studies that are designed to elucidate the precise mechanisms and implications of the spatiotemporal organization and (ii) incorporated into existing theoretical network models of stimulus representation and information processing in the mammalian cortex.

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Two-photon fluorescence images of a targeted whole-cell recording from a GFP-labelled periglomerular cell (left) and GFP-labelled olfactory receptor neurons forming glomeruli (right) in the mouse olfactory bulb. (Mice generated by H. Monyer and R. Sprengel)

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Morphological reconstructions of cells involved in sensory processing in the olfactory pathway.

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An example trace of an overt stimulus-evoked subthreshold oscillation in mitral cell membrane potential in the mouse olfactory bulb in vivo.

Selected publications:

  • Schaefer, AT, Margrie, TW (2007) Spatiotemporal representations in the olfactory system. Trends in Neuroscience 30 (3) p92-100.
  • Schaefer AT, Angelo K, Spors H, Margrie TW (2006) Neuronal oscillations enhance stimulus discrimination by ensuring action potential precision. PLoS Biology 4 (6): e163
  • Brecht, M., Schneider, M., Sakmann, B., and Margrie, T. W. (2004) Movements evoked by intracellular stimulation of single identified neurons in the deep layers of the motor cortex Nature 427 p115-122
  • Margrie, T. W., Meyer, A., Caputi, A. Monyer, H., Hasan, M. T., Schaefer, A. T., Denk, W., and Brecht, M. (2003) Targeted whole-cell recordings in the mammalian brain in vivo Neuron 39 p11-20
  • Margrie TW, Schaefer AT. (2003) Theta oscillation coupled spike latencies yield computational vigour in a mammalian sensory system. J Physiol 546: 363-74
  • Margrie TW, Brecht M, Sakmann B. (2002) In vivo, low-resistance, whole-cell recordings from neurons in the anaesthetized and awake mammalian brain Pflugers Arch 444: 491-8
  • Margrie TW, Sakmann B, Urban NN. (2001) Action potential propagation in mitral cell lateral dendrites is decremental and controls recurrent and lateral inhibition in the mammalian olfactory bulb. Proc Natl Acad Sci U S A 98: 319-24