A high-density, high-channel count, multiplexed μECOG array for auditory-cortex recordings

摘要

Our understanding of the large-scale population dynamics of neural activity is limited, in part, by our inability to record simultaneously from large regions of the cortex. Here, we validated the use of a large-scale active microelectrode array that simultaneously records 196 multiplexed micro-electrocortigraphical (糆CoG) signals from the cortical surface at a very high density (1,600 electrodes/cm2). We compared 糆CoG measurements in auditory cortex using a custom active electrode array to those recorded using a conventional passive 糆CoG array. Both of these array responses were also compared with data recorded via intrinsic optical imaging, which is a standard methodology for recording sound-evoked cortical activity. Custom active 糆CoG arrays generated more veridical representations of the tonotopic organization of the auditory cortex than current commercially available passive 糆CoG arrays. Furthermore, the cortical representation could be measured efficiently with the active arrays, requiring as little as 13.5 s of neural data acquisition. Next, we generated spectrotemporal receptive fields from the recorded neural activity on the active 糆CoG array and identified functional organizational principles comparable to those observed using intrinsic metabolic imaging and single-neuron recordings. This new electrode array technology has the potential for large-scale, temporally precise monitoring and mapping of the cortex, without the use of invasive penetrating electrodes.