Jamille F. Hetke

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The cellular generation and spatial distribution of gamma frequency (40-100 Hz) activity was examined in the hippocampus of the awake rat. Field potentials and unit activity were recorded by multiple site silicon probes (5- and 16-site shanks) and wire electrode arrays. Gamma waves were highly coherent along the long axis of the dentate hilus, but average(More)
Pyramidal cells in the CA1 hippocampal region displayed transient network oscillations (200 hertz) during behavioral immobility, consummatory behaviors, and slow-wave sleep. Simultaneous, multisite recordings revealed temporal and spatial coherence of neuronal activity during population oscillations. Participating pyramidal cells discharged at a rate lower(More)
We developed a variety of 54-channel high-density silicon electrode arrays (polytrodes) designed to record from large numbers of neurons spanning millimeters of brain. In cat visual cortex, it was possible to make simultaneous recordings from >100 well-isolated neurons. Using standard clustering methods, polytrodes provide a quality of single-unit isolation(More)
An important aspect of the development of cortical prostheses is the enhancement of suitable implantable microelectrode arrays for chronic neural recording. The objective of this study was to investigate the recording performance of silicon-substrate micromachined probes in terms of reliability and signal quality. These probes were found to consistently and(More)
This paper describes the development of a high-density electronic interface to the central nervous system. Silicon micromachined electrode arrays now permit the long-term monitoring of neural activity in vivo as well as the insertion of electronic signals into neural networks at the cellular level. Efforts to understand and engineer the biology of the(More)
The interface between micromachined neural microelectrodes and neural tissue plays an important role in chronic in vivo recording. Electrochemical polymerization was used to optimize the surface of the metal electrode sites. Electrically conductive polymers (polypyrrole) combined with biomolecules having cell adhesion functionality were deposited with great(More)
Silicon micromachining and thin-film technology have been employed to fabricate iridium stimulating arrays which can be used to excite discrete volumes of the central nervous system. Silicon multichannel probes with thicknesses ranging from 1 to 40 microns and arbitrary two-dimensional shapes can be fabricated using a high-yield, circuit-compatible process.(More)
Daryl R. Kipke,1,6 William Shain,2 György Buzsáki,3 E. Fetz,4 Jaimie M. Henderson,5 Jamille F. Hetke,6 and Gerwin Schalk2 1Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, 2Wadsworth Center, New York State Department of Health, Albany, New York 12201, 3Center for Molecular and Behavioral Neuroscience, Rutgers, The(More)
A bulk-micromachined multichannel silicon probe capable of selectively delivering chemicals at the cellular level as well as electrically recording from and stimulating neurons in vivo has been developed. The process buries multiple flow channels in the probe substrate, resulting in a hollow-core device. Microchannel formation requires only one mask in(More)
Strength characteristics of thin-silicon probes in neural tissues have been determined experimentally. It is shown that by proper selection of the substrate length, width, and thickness, silicon substrates can be designed and used to penetrate a variety of biological tissues without breakage or excessive dimpling. Thin-silicon structures have a maximum(More)