Abstract
This paper present results of a multi-disciplinary project that is developing a microchip-based neural prosthesis for the hippocampus, a region of the brain responsible for the formation of long-term memories. Damage to the hippocampus is frequently associated with epilepsy, stroke, and dementia (Alzheimer's disease) and is considered to underlie the memory deficits related to these neurological conditions. The essential goals of the multi-laboratory effort include: (1) experimental study of neuron and neural network function--how does the hippocampus encode information? (2) formulation of biologically realistic models of neural system dynamics--can that encoding process be described mathematically to realize a predictive model of how the hippocampus responds to any event? (3) microchip implementation of neural system models--can the mathematical model be realized as a set of electronic circuits to achieve parallel processing, rapid computational speed, and miniaturization? and (4) creation of hybrid neuron-silicon interfaces-can structural and functional connections between electronic devices and neural tissue be achieved for long-term, bi-directional communication with the brain? By integrating solutions to these component problems, we are realizing a microchip-based model of hippocampal nonlinear dynamics that can perform the same function as part of the hippocampus. Through bi-directional communication with other neural tissue that normally provides the inputs and outputs to/from a damaged hippocampal area, the biomimetic model could serve as a neural prosthesis. A proof-of-concept will be presented in which the CA3 region of the hippocampal slice is surgically removed and is replaced by a microchip model of CA3 nonlinear dynamics--the "hybrid" hippocampal circuit displays normal physiological properties. How the work in brain slices is being extended to behaving animals also will be described.
| Original language | English |
|---|---|
| Pages (from-to) | 157-197 |
| Number of pages | 41 |
| Journal | IEEE Reviews in Biomedical Engineering |
| Volume | 1 |
| DOIs | |
| State | Published - 2008 |
Bibliographical note
Funding Information:widely based effort now in effect and planned for the future. The National Science Foundation (NSF) also has seen sustained budget increases, again with federal investment being particularly strong for sub-fields at the interface between engineering and the neurosciences. The NSF has created several of its premier Engineering Research Centers in research areas that overlap strongly with core areas of biomedical and neural engineering, e.g., the Biomimetic MicroElectronic Systems Center at the University of Southern California. The Department of Defense (DoD), including the Defense Advanced Research Projects Agency (DARPA), the Office of Naval Research (ONR), and the Telemedicine and Advanced Technology Research Center (TATRC), among others, also has supported new ventures that require integrated efforts by neuroscientists and engineers, for example, to identify biological principals of system design that then have been used successfully to develop neural prostheses, brain–computer interfaces, and large-scale hardware implementations of neural systems that can interface directly with the brain. Biological principals of brain function also have been used to guide the design of next-generation computer architectures required to support more “cognitive” software for higher-level decision making required for bio-inspired robotics. Finally, the last half of the 20th century has witnessed a sustained increase in philanthropic activity directed specifically at biomedical and neural engineering (e.g., The Whitaker Foundation), increasing both the quantity and quality of research activity, and expanding education and training activity in biomedical engineering.
Funding Information:
A very promising silicon-based electrode array design has been developed by the VSAMUEL consortium (European Union, Grant #IST-1999-10073 termed ACREO (ACREO AB, Sweden) microelectrode arrays [138], [139]. These microelectrodes have 1 to 8 recording shafts, are very versatile and flexible and appear to have very promising insertion mechanics [138]. These also represent a major microelectrode manufacturing capability in the European Union.
ASJC Scopus subject areas
- Biomedical Engineering