Event:

Dr. Berger leads a multi-disciplinary collaboration that includes the University of Southern California, the City University of Hong Kong, Wake Forest University, and the University of Kentucky, and that is developing a microchip-based neural prosthesis for the hippocampus, a region of the brain responsible for long-term memory. Damage to the hippocampus is frequently associated with epilepsy, stroke, and dementia (Alzheimer’s Disease), and is considered to underlie the memory deficits characteristic of these neurological conditions. The essential goals of Dr. Berger’s multi-laboratory effort include: (1) experimental study on how the hippocampus encodes information, (2) formulation of biologically realistic models of neural system dynamics, (3) microchip implementation of neural system models, and (4) creation of conformal neuron-electrode interfaces. A proof-of-concept is presented using rats or monkeys that have been chronically implanted with stimulation/recording micro-electrodes throughout multiple regions of the CA3 and CA1 hippocampus, and that have been trained using a delayed, non-match-to-sample task (or delayed match-to-sample in the case of monkeys). After animals are well-trained, hippocampal function is blocked pharmacologically, and then in the presence of that blockade, hippocampal memory function is restored by a multi-input, multi-output model of hippocampal nonlinear dynamics that interacts bi-directionally with the in vivo hippocampus. Using the same procedures in implanted animals with intact, normally functioning hippocampi substantially enhances memory strength and thus, learned behavior is improved. Most recently, the team has extended this approach to humans, with recordings from hippocampus of epilepsy patients during memory tasks, and highly successful predictive models. These results show for the first time that it is possible to create “hybrid electronic-biological” systems that mimic physiological properties of the brain, and thus, biomimetic systems that may be used as neural prostheses to restore damaged brain regions – even those regions that underlie cognitive function.