Our perceptions, actions, and memories emerge from the communications that occur between the cells in our nervous system. This remarkable feat of physiology is made possible by the billions of precisely tuned synaptic connections between the neurons of the brain. These connections are not hard-wired by the genome, though. In all animals, from insects up to humans, neurons use the information contained in sensory and motor experience to shape their synaptic connections. I am interested in understanding how this process works in a variety of animal species and neural circuits. In particular, I want to develop an integrated picture of learning that links cellular-level circuit properties to the information processing that determines how animals perceive, act and remember.
- Learning and memory
- Synaptic plasticity
- Memory consolidation
- Multisensory integration
- Inhibitory interneurons
- 2-photon microscopy
- Behavioural studies
- Chemogenetics and optogenetics
- Computational modelling
Neurophysiology, Systems Neuroscience and Computational Neuroscience
Sensory learning in in early life
When they are young, vertebrate brains go through periods of extreme sensitivity to sensory information. For example, in mammals, birds, fish and amphibians, the wiring of synaptic connections in the midbrain depends upon normal sensory experience soon after birth. Without this experience, animals do not orient towards objects of interest in the normal manner. Using patch clamp recordings, optogenetics and computational modelling we are working to understand how visual and auditory inputs to the midbrain interact in order to promote spatial alignment in a young animal's perception of the objects around them.
Interactions between new learning and old memories
Memories are not formed in a vacuum. When we learn something new it is necessarily incorporated into the same circuits that store our older memories. Exactly how this occurs, though, depends on whether the new information matches the statistical patterns contained in the previous memories. When new information conflicts with previous patterns, the medial prefrontal cortex plays an important role in helping to modify existing memory traces. Using behavioural studies paired with electrophysiology and chemogenetics we are examining the role of different cell types in the medial prefrontal cortex in mediating conflicts between new information and old memories.
Transmission of error signals in multilayer neural circuits
Neural circuits can perform more complicated tasks when they are arranged in multiple layers. This principal of neural computation presents a conundrum, though, because multilayer circuits must somehow ensure that changes to connections in higher layers and lower layers act in concert. Computer models suggest that multilayer circuits can achieve this by transmitting error signals across multiple layers in order to modulate focal synaptic changes. Using computational models and two-photon imaging paired with optogenetics and transmitter uncaging, we are investigating how error signals propagated through multiple layers of neural circuits can shape synaptic changes.
BIOB34H3: Animal physiology