Long-term near-continuous recording with neuropixels probes in healthy and epileptic rats

Abstract

Neuropixels probes have become a crucial tool for high-density electrophysiological recordings. Although most research involving these electrodes is in acute preparations, some scientific inquiries require long-term recordings in freely moving animals. Recent reports have presented prosthesis designs for chronic recordings, but some of them do not allow for probe recovery, which is desirable given their cost. Others appear to be fragile, as these articles describe numerous broken implants. This fragility presents a challenge for recordings in rats, particularly in epilepsy models where strong mechanical stress impinges upon the prosthesis. To overcome these limitations, we present a new implant specifically designed to protect the probes from strong shocks and enable the safe retrieval of electrodes after experiments. This implant was successfully used to record from healthy and epileptic rats for up to three weeks almost continuously, with a probe retrieval and reuse success rate of 91%, improving previously described recycling performances.

An adaptable, reusable, and light implant for chronic Neuropixels probes

“…With these probes, experimenters have produced brain-wide maps of behaviors in head-restrained mice using acute recordings (Allen et al, 2019; International Brain Laboratory et al, 2023; Steinmetz et al, 2019; Stringer et al, 2019). To track neurons across days, and to use freely moving animals, the probes can be implanted chronically, with procedures that are permanent (Jun et al, 2017; Steinmetz et al, 2021) or recoverable (Ghestem et al, 2023; Juavinett et al, 2019; Luo et al, 2020; Steinmetz et al, 2021; van Daal et al, 2021). Permanent implants are lightweight and stable, but their use at scale is not financially feasible.…”

Repix: reliable, reusable, versatile chronic Neuropixels implants using minimal components

“…And across users, explantation was high at 83%. This is similar to the Apollo implant, which is 86% when taking into account all probe errors, and only slightly lower than the 10/11 successful retrievals in the single lab experience in rats in Ghestem et al 26 . Repix has been used more times (e.g.…”

“…As the Neuropixels recording technology evolved and matured, researchers developed solutions to chronically implanting Neuropixels probes. They have a common design principle using payload and docking modules and have been effectively used for some combination of recording from Neuropixels 1.0; Neuropixels 2.0; in mice or rats; with the ability to reuse probes 3,17,19,20,[23][24][25][26] . Repix combines all these qualities to ensure longterm recordings in an aluminum system that is strong enough for rats and light enough for mice; which can accommodate any probe type; in assays that span rodent behaviors, including freely-moving, head-fixed, and social behaviors; where probes can be reused; all in a solution with a minimal number of components that can be adapted for individual use cases.…”

Detection of Cell Assemblies in High-Density Extracellular Electrophysiological Recordings

“…Future algorithms could address this issue, as well as enable a more thorough view of the available cell assemblies through more sensitive algorithms as well as algorithms that are better optimized to run on very large datasets (e.g. [94][95][96]). Finally, in recent years, population activity has been investigated with the use of machine learning and neural networks (e.g.…”