Laboratory of Oscillations & Plasticity
The ability to learn from experience is the cornerstone of intelligent behaviour. While awake exploration is necessary to acquire new information, subsequent sleep is thought to play a role in the reorganisation and consolidation of memory traces in the brain. The overall goal of our laboratory is to understand the cellular and synaptic mechanisms underlying these sequential stages of learning in mammalian cortical circuits
Fluctuations in brain function across the sleep-wake cycle are characterised by specific patterns of oscillatory brain activity. These rhythms range from the slow oscillations (< 1 Hz) that propagate across the entire cortical mantle during deep sleep, to the fast oscillations (up to 250 Hz) that can synchronise activity within local cortical circuits. Whether the oscillatory nature of brain activity is itself critical for cognitive function remains hotly debated, but different brain rhythms clearly represent distinct modes of cortical circuit processing, and thus provide a rubric for translating our understanding of cortical plasticity between the cellular and behavioural levels.
In order to understand how the oscillatory state of cortical networks governs neuronal communication and plasticity, we focus on two systems in the rodent brain: cortical loops within the medial temporal lobe involved in episodic memory, and thalamocortical loops involved in sensorimotor integration. We use a combination of electrophysiological, optical imaging and optogenetic techniques to dissect these mechanisms in vitro and in vivo.
The impact of a breakdown in the delicate mechanisms generating brain rhythms can be observed most dramatically in epilepsy. The recurrent seizures that characterise this disorder are due to abnormal bursts of brain activity, leading to the transient loss of cognitive, sensory or motor function, and having a lasting impact on learning and memory. Numerous brain disorders are associated with more subtle changes in cortical synchronization, including schizophrenia, Parkinson's Disease and Alzheimer’s Disease. We also study rodent models in order to understand the pathogenesis and treatment of these brain disorders at the circuit level.
A minimal circuit underlying hippocampal gamma-frequency network oscillations.
Whisker-evoked responses in a layer 2/3 pyramidal neuron, monitored using whole-cell patch-clamp recordings in vivo (in collaboration with Louise Upton, OXION).
Optical imaging & control