Michael C Ashby

Biography

Our research addresses the development of brain circuitry early in life, when anatomical and synaptic plasticity coordinate dramatically to produce functional circuits in the mammalian cortex. Using high resolution optical stimulation and recording combined with molecular, genetic and electrophysiological methods, I aim to define how neonatal sensory experience influences the normal and pathological cortical circuit development that underlies lifelong brain function.Connectivity in a barrel This is an example of the type of connectivity map generated using 2-photon stimulation and patch clamp electrophysiology to detect and measure synaptic connections. Each sphere represents a neuron inside the barrel structure that is found in the sensory cortex. The green neuron was recorded during the experiment and is shown here with all its dendrites. The other neurons were stimulated during the experiment to find those that make synaptic connections with the recorded cell. Only a small proportion of cells, those shown in colour, are connected. This type of map tells us about rates of connectivity, the properties of those synapses and the geometric relationship between connected cells. Comparing these maps at different stages of early postnatal development allows us to understand the processes involved in the formation of circuitry in the sensory cortex (Ashby & Isaac 2011, Neuron 70:510-521).

Research Interest

Development of brain circuitry early in life