Biology subjects

Takacs, F.

Publications and source records attributed to Takacs, F..

3 recordsLinked to original sources

bioRxiv2023

Tracking neurons across days with high-density probes

Neural activity spans multiple scales from milliseconds to months. Its evolution can be recorded with chronic electrodes, and especially with high-density arrays such as Neuropixels probes, which measure each spike at tens of sites and record hundreds of neurons. These arrays often record units with consistent spike waveforms over time, but produce vast amounts of data that require new approaches for tracking neurons across recordings. To meet this need, we developed UnitMatch, an open-access pipeline that operates after spike sorting, based only on each units average spike waveform. We tested UnitMatch in Neuropixels recordings from the mouse brain, where it tracked neurons across weeks. In visual cortex, a neurons selectivity for visual stimuli and correlation with other neurons remained stable over days. In striatum, neuronal responses changed across days during learning of a task. UnitMatch is thus a promising tool to reveal invariance or plasticity in neural activity across days.

neuroscience↗

bioRxiv2023

Reusable, flexible, and lightweight chronic implants for Neuropixels probes

Electrophysiology has proven invaluable to record neural activity, and the development of Neuropixels probes dramatically increased the number of recorded neurons. These probes are often implanted acutely, but acute recordings cannot be performed in freely moving animals and the recorded neurons cannot be tracked across days. To study key behaviors such as navigation, learning, and memory formation, the probes must be implanted chronically. An ideal chronic implant should (1) allow stable recordings of neurons for weeks; (2) allow reuse of the probes after explantation; (3) be light enough for use in mice. Here, we present the "Apollo Implant", an open-source and editable device that meets these criteria and accommodates up to two Neuropixels 1.0 or 2.0 probes. The implant comprises a "payload" module which is attached to the probe and is recoverable, and a "docking" module which is cemented to the skull. The design is adjustable, making it easy to change the distance between probes, the angle of insertion, and the depth of insertion. We tested the implant across eight labs in head-fixed mice, freely moving mice, and freely moving rats. The number of neurons recorded across days was stable, even after repeated implantations of the same probe. The Apollo implant provides an inexpensive, lightweight, and flexible solution for reusable chronic Neuropixels recordings.

neuroscience↗

bioRxiv2020

Scanned optogenetic control of mammalian somatosensory input to map input-specific behavioral outputs

Somatosensory stimuli guide and shape behavior, from immediate protective reflexes to longer-term learning and high-order processes related to pain and touch. However, somatosensory inputs are challenging to control in awake mammals due to the diversity and nature of contact stimuli. Application of cutaneous stimuli is currently limited to relatively imprecise methods as well as subjective behavioral measures. The strategy we present here overcomes these difficulties by achieving spatiotemporally precise, remote and dynamic optogenetic stimulation of skin by projecting light to a small defined area in freely-behaving mice. We mapped behavioral responses to specific nociceptive inputs and revealed a sparse code for stimulus intensity: using the first action potential, the number of activated nociceptors governs the timing and magnitude of rapid protective pain-related behavior. The strategy can be used to define specific behavioral repertoires, examine the timing and nature of reflexes, and dissect sensory, motor, cognitive and motivational processes guiding behavior.

neuroscience↗