Wireless hippocampal neural recording via a multiple input RF receiver to construct place-specific firing fields.
This paper reports scientifically meaningful in vivo experiments using a 32-channel wireless neural recording system (WINeR). The WINeR system is divided into transmitter (Tx) and receiver (Rx) parts. On the Tx side, we had WINeR-6, a system-on-a-chip (SoC) that operated based on time division multiplexing (TDM) of pulse width modulated (PWM) samples. The chip was fabricated in a 0.5-µm CMOS process, occupying 4.9 × 3.3 mm(2) and consuming 15 mW from ±1.5V supplies. The Rx used two antennas with separate pathways to down-convert the RF signal from a large area. A time-to-digital converter (TDC) in an FPGA converted the PWM pulses into digitized samples. In order to further increase the wireless coverage area and eliminate blind spots within a large experimental arena, two receivers were synchronized. The WINeR system was used to record epileptic activities from a rat that was injected with tetanus toxin (TT) in the dorsal hippocampus. In a different in vivo experiment, place-specific firing fields of place cells, which are parts of the hippocampal-dependent memory, were mapped from a series of behavioral experiments from a rat running in a circular track. Results from the same animal were compared against a commercial hard-wired recording system to evaluate the quality of the wireless recordings.
GT-Bionics lab, School of Electrical and Computer Engineering at the Georgia Institute of Technology, Atlanta, GA 30308, USA.
Seung Bae
SB
Lee
Joseph R
JR
Manns
Maysam
M
Ghovanloo
D000200:Action Potentials; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D004567:Electrodes, Implanted; D055724:Electrophysiological Phenomena; D004867:Equipment Design; D006624:Hippocampus / Q000502:physiology* / Q000601:surgery*; D008297:Male; D011846:Radio Waves; D051381:Rats; D020318:Rats, Long-Evans; D017207:Rats, Sprague-Dawley; D058998:Remote Sensing Technology / Q000295:instrumentation; D012640:Seizures / Q000175:diagnosis / Q000503:physiopathology; D012815:Signal Processing, Computer-Assisted; D013686:Telemetry / Q000295:instrumentation; D059015:Wireless Technology / Q000295:instrumentation*