My laboratory is interested in neurobiological mechanisms of learning and memory - from the molecular to the behavioral levels - with a major focus on rapid forms of learning. The brain structures on which we concentrate, which include the hippocampus, amygdala, and perirhinal cortex, are implicated in aspects of declarative and emotional learning. They are also implicated in a aging-related forms of neuropathology and accompanying behavioral and mental changes. One working hypothesis is that rapid learning emerges from use-dependent modifications, such as long-term potentiation, in pre-existing synaptic connections. Accordingly, a long-term thrust of my research has been to develop techniques that enable a rigorous analysis of the biophysics and microphysiology of synapses and neurons in brain structures such as the hippocampus, amygdala and perirhinal cortex that have been implicated in rapid learning. To this end, we apply powerful optical and biophysical techniques to study rapid and persistent synaptic modifications. The in vitro methods include patch-clamp recording, quantal analysis, confocal microscopy and calcium imaging, and anatomical reconstructions of recorded neurons. More recently the research has expanded to include characterization of the neural circuits and systems involved in rapid learning. The in vivo methods include tracing axonal projections of physiologically characterized neurons, behavioral neurophysiological studies, and analysis of a rapidly-induced form of Pavlovian conditioning whose underlying circuitry is relatively simple. The experimental knowledge we gain about synapses, circuits, systems and behavior is being incorporated into computational models for theoretical studies.
Xiang, Z., Greenwood, A. C., Kairiss, E. W., & Brown, T. H. (1994). Quantal mechanisms of long-term potentiation in hippocampal mossy-fiber synapses. Journal of Neurophysiology, 71, 2552-2556.
Canli, T., and Brown, T. H. (1996). Amygdala stimulation enhances the rat eyeblink reflex through a short latency mechanism. Behavior Neuroscience, 1, 51-59.