Our research interests include the neurobiology of learning and emotional memory and the mechanisms and roles of neuromodulation in large neural networks. We use a multi-disciplinary approach that includes in vitro, in vivo and computational techniques.
The primary focus of our research is to understand how large populations of neurons store and communicate information across brain regions. Large scale recording techniques (such as fMRI and high-density single units) have significantly increased our understanding of the normal and abnormal brain. It is now clear that neural processing relies on the dynamic exchange of information between large groups of neurons. How is this communication achieved reliably? How are multiple streams of information simultaneously processed without interfering with each other? How does learning 'optimize' large scale computations? Current research foci include complex spatial navigation in the hippocampal system.
The secondary focus is to understand how neural computations can be dynamically re-configured to reflect the constraints dictated by changes in behavioral, emotional and cognitive contexts. These contexts are almost always associated with the release of neuromodulators such as dopamine (e.g. reinforcement learning), acetylcholine (e.g. sleep and memory) or serotonin (e.g. motivation and emotion). How do these substances change the flow of information and regulate learning and memory in specific brain areas? Because many diseases such as schizophrenia, drug addiction and posttraumatic stress disorder (PTSD) clearly depend on these neuromodulatory systems, we beleive that understanding the mechanisms of neuromodulation is crucial to elucidating the neural bases of normal and defficient cognitive and emotional processing. Current research foci include memory consolidation during sleep, PTSD and empathy.
The experimental aspects of this research are conducted using a combination of in vitro and in vivo techniques in the rat. We use state of the art neurophysiology techniques that include two-way real-time brain-machine interfaces and "hyperdrives" allowing for the simultaneous recordings from over 50 neurons in the behaving animal. We also recently started using optogenetic tools to manipulate neural activity in vivo using light, and the use of a small robot that interacts with the rats!
The theoretical aspects of our work involves the use of computational modeling techniques to simulate the activity of single cells and networks of interconnected cells. These computer simulations reproduce and explain experimental data, and generate predictions that can in turn be tested experimentally.