Abstract
The use of Neuropixels probes for chronic neural recordings is in its infancy and initial studies leave questions about long-term stability and probe reusability unaddressed. Here we demonstrate a new approach for chronic Neuropixels recordings over a period of months in freely moving rats. Our approach allows multiple probes per rat and multiple cycles of probe reuse. We found that hundreds of units could be recorded for multiple months, but that yields depended systematically on anatomical position. Explanted probes displayed a small increase in noise compared to unimplanted probes, but this was insufficient to impair future single-unit recordings. We conclude that cost-effective, multi-region, and multi-probe Neuropixels recordings can be carried out with high yields over multiple months in rats or other similarly sized animals. Our methods and observations may facilitate the standardization of chronic recording from Neuropixels probes in freely moving animals.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Numerous major changes were made since Revision 2 in response to the initial round of review in eLife. These reviews can be viewed as part of bioRxiv's Preprint Review service. Major changes: 1. We have increased greatly the amount of information detailing the construction and implantation procedures in the main text, including adding two new figures. In the revised manuscript, Fig. 2 contains images demonstrating the implant construction procedure, including the specific steps that are suggested by the reviewer. Fig. 3 provides images demonstrating the key surgical procedures associated with implantation and explantation. In addition, the Methods section has been significantly expanded to contain additional detailed information about implant construction, implantation and explantation. 2. We have implemented an elaborated sum-of-exponentials regression model in which initial counts of fast-decaying and slow-decaying units no longer have a constant ratio but instead depend on separate linear combinations of the regressors. The results are presented in a supplemental figure. 3. We have performed additional analyses to compare the uncurated and curated data for those subset of sessions (n=25) in which curation had been performed.