Ultra-miniature headstage with 6-channel drive and vacuum-assisted micro-wire implantation for chronic recording from the neocortex.
We describe a head-stage, with precision microtranslators for the chronic placement of micro-wire electrodes in the neocortex, that minimizes compressive damage to the brain. The head-stage has a diameter of 5.8 mm and allows six electrodes, separated by 450 microm on a hexagonal grid, to be individually and continuously positioned throughout a depth of approximately 3 mm. Suction is used to transiently support the dura against a curved array of tubes that guide and stabilize the electrodes as a means to prevent compression of the neocortex as the electrodes breach the dura. With this headstage we recorded extracellular signals in a rat immediately after surgery. Single-unit waveforms at a given electrode position were stable for at least several hours in the freely behaving animal and were obtained throughout the depth of the neocortex for at least 2 months. Electrophysiological records and histological examination showed that the upper layers of the neocortex were intact and minimally damaged after the implantation.
Venkatachalam
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Department of Physics, University of California, La Jolla 92093, USA.
Fee
M S
MS
Kleinfeld
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D
D000818:Animals; D004567:Electrodes, Implanted; D005260:Female; D008839:Microelectrodes; D008904:Miniaturization; D019579:Neocortex / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D014618:Vacuum