This paper describes the design and implementation of a wireless neural telemetry system that enables new experimental paradigms, such as neural recordings during rodent navigation in large outdoor environments. RoSco, short for Rodent Scope, is a small lightweight user-configurable module suitable for digital wireless recording from freely behaving small animals. Due to the digital transmission technology, RoSco has advantages over most other wireless modules of noise immunity and online user-configurable settings. RoSco digitally transmits entire neural waveforms for 14 of 16 channels at 20 kHz with 8-bit encoding which are streamed to the PC as standard USB audio packets. Up to 31 RoSco wireless modules can coexist in the same environment on non-overlapping independent channels. The design has spatial diversity reception via two antennas, which makes wireless communication resilient to fading and obstacles. In comparison with most existing wireless systems, this system has online user-selectable independent gain control of each channel in 8 factors from 500 to 32,000 times, two selectable ground references from a subset of channels, selectable channel grounding to disable noisy electrodes, and selectable bandwidth suitable for action potentials (300 Hz–3 kHz) and low frequency field potentials (4 Hz–3 kHz). Indoor and outdoor recordings taken from freely behaving rodents are shown to be comparable to a commercial wired system in sorting for neural populations. The module has low input referred noise, battery life of 1.5 hours and transmission losses of 0.1% up to a range of 10 m.
References
[1]
Renshaw B, Forbes A, Morison BR (1940) Activity of Isocortex and Hippocampus: Electrical Studies with Micro-Electrodes. Journal of Neurophysiology 3: 74–105.
[2]
Hubel DH, Wiesel TN (1959) Receptive fields of single neurones in the cat's striate cortex. The Journal of Physiology 148: 574–591. doi: 10.1113/jphysiol.2009.174151
[3]
Skutt HR, Beschle RG, Moulton DG, Koella WP (1967) New subminiature amplifier-transmitters for telemetering biopotentials. Electroencephalography and Clinical Neurophysiology 22: 275–277. doi: 10.1016/0013-4694(67)90234-9
[4]
Gosselin B (2011) Recent Advances in Neural Recording Microsystems. Sensors 11: 4572–4597. doi: 10.3390/s110504572
[5]
Kliese R, Ball D (2013) RoSco Schematics. figshare (http://dx.doi.org/10.6084/m9.figshare.88？1900).
[6]
Kliese R, Ball D (2013) RoSco Firmware and Documents. figshare (http://dx.doi.org/10.6084/m9.figshare.88？1900).
[7]
Fenton AA, Jeffery KJ, Donnett JG, Vertes RP, Stackman J (2011) Neural Recording Using Digital Telemetry. Electrophysiological Recording Techniques: Humana Press. pp. 77–101.
[8]
Miranda H, Gilja V, Chestek CA, Shenoy KV, Meng TH (2010) HermesD: A High-Rate Long-Range Wireless Transmission System for Simultaneous Multichannel Neural Recording Applications. IEEE Transactions on Biomedical Circuits and Systems 4: 181–191. doi: 10.1109/tbcas.2010.2044573
[9]
Chestek CA, Gilja V, Nuyujukian P, Kier RJ, Solzbacher F, et al. (2009) HermesC: Low-Power Wireless Neural Recording System for Freely Moving Primates. IEEE Transactions on Neural Systems and Rehabilitation Engineering 17: 330–338. doi: 10.1109/tnsre.2009.2023293
[10]
Hampson RE, Collins V, Deadwyler SA (2009) A wireless recording system that utilizes Bluetooth technology to transmit neural activity in freely moving animals. Journal of Neuroscience Methods 182: 195–204. doi: 10.1016/j.jneumeth.2009.06.007
[11]
Chae MS, Yang Z, Yuce MR, Hoang L, Liu W (2009) A 128-Channel 6 mW Wireless Neural Recording IC With Spike Feature Extraction and UWB Transmitter. IEEE Transactions on Neural Systems and Rehabilitation Engineering 17: 312–321. doi: 10.1109/tnsre.2009.2021607
[12]
Chen H-Y, Wu J-S, Hyland B, Lu X-D, Chen J (2008) A low noise remotely controllable wireless telemetry system for single-unit recording in rats navigating in a vertical maze. Medical and Biological Engineering and Computing 46: 833–839. doi: 10.1007/s11517-008-0355-6
[13]
Harrison RR, Kier RJ, Greger B, Solzbacher F, Chestek CA, et al.. (2008) Wireless neural signal acquisition with single low-power integrated circuit; May. pp. 1748–1751.
[14]
Farshchi S, Pesterev A, Guenterberg E, Mody I, Judy JW (2007) An Embedded System Architecture for Wireless Neural Recording; May. pp. 327–332.
[15]
Szuts TA, Fadeyev V, Kachiguine S, Sher A, Grivich MV, et al. (2011) A wireless multi-channel neural amplifier for freely moving animals. Nature Neuroscience 14: 263–269. doi: 10.1038/nn.2730
[16]
Knapen G (1997) Universal Serial Bus Device Class Definition for Audio Devices. USB Implementers Forum.
[17]
Windels F, Kiyatkin EA (2006) General anesthesia as a factor affecting impulse activity and neuronal responses to putative neurotransmitters. Brain Research 1086: 104–116. doi: 10.1016/j.brainres.2006.02.064
[18]
Baranauskas G, Maggiolini E, Vato A, Angotzi G, Bonfanti A, et al. (2012) Origins of 1/f2 scaling in the power spectrum of intracortical local field potential. Journal of Neurophysiology 107: 984–994. doi: 10.1152/jn.00470.2011
Muller S, Massarani P (2001) Transfer-Function Measurement with Sweeps. J Audio Eng Soc 49: 443–471.
[21]
O'Keefe J, Recce ML (1993) Phase relationship between hippocampal place units and the EEG theta rhythm. Hippocampus 3: 317–330. doi: 10.1002/hipo.450030307
[22]
Skaggs WE, McNaughton, Bruce L, Wilson MA, Barnes CA (1996) Theta phase precession in hippocampal neuronal populations and the compression of temporal sequences. Hippocampus 6: 149–172. doi: 10.1002/(sici)1098-1063(1996)6:2<149::aid-hipo6>3.0.co;2-k
[23]
Fan D, Rich D, Holtzman T, Ruther P, Dalley JW, et al. (2011) A Wireless Multi-Channel Recording System for Freely Behaving Mice and Rats. PLoS ONE 6: e22033. doi: 10.1371/journal.pone.0022033
[24]
Quiroga RQ, Nadasdy Z, Ben-Shaul Y (2004) Unsupervised Spike Detection and Sorting with Wavelets and Superparamagnetic Clustering. Neural Computation 16: 1661–1687. doi: 10.1162/089976604774201631
[25]
Nyquist H (1928) Certain Topics in Telegraph Transmission Theory. Transactions of the American Institute of Electrical Engineers 47: 617–644. doi: 10.1109/t-aiee.1928.5055024
