The role of the hippocampus in associative memory is the establishment of long-term, declarative memories. For example, memories for facts, names, and life experiences. Damage to the hippocampus leads to loss of ability to convert short-term memory to new long-term memories.

hippocampus mapping
Clinical applications of a biomimetic implant which replaces damaged brain function might be Stroke [preferential damage to CA1 neurons], Brain Trauma [preferential damage to hippocampal hilar neurons], Epilepsy [preferential damage to CA3 pyramidal cells], and Alzheimer’s Disease [preferential damage throughout the hippocampus].

Implantable Biomimetic VLSI device

Replacing a Component of the Hippocampal Neural Circuit with a Biomimetic VLSI Device

A candidate device is a TMSC 0.18 micron CMOS (MOSIS) microchip.

Its circuitry includes A/D and D/A controllers, signal processing of input waveforms for population spike waveform identification and amplitude measurement.

Its footprint allows expansion to 100 CA3 models if required, i.e., replacement of 100 hippocampal circuits.
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Cortical Neural Prosthetics at USC's Biomimetic MicroElectronic Systems

"Link the brain to the external world by computer processing the recorded neural signal to extract the subject’s command to control an external device."  — Andrew B. Schwartz 2004

The newly developed systems at BMES will allow bi-directional communication with tissue and by doing so enable implantable/portable microelectronic devices to treat presently incurable human diseases such as blindness, paralysis, and memory loss.

These systems use cortical signals as inputs to a brain–machine interface. The elements of these systems are (1) Recording Units (microelectrode arrays) comprised of microwires, silicon micromachined microprobes, and tissue reactions, (2) Decoding Units (extraction algorithms), and (3) Actuators (prosthetic effectors) comprised of computers, robotic arms or stimulators.

Go to the USC BMES Site »
USC Biomimetic MicroElectronic Systems