Jarrod Dowdall
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Jarrod Dowdall
@jarroddowdall.bsky.social
150 followers 210 following 24 posts
Systems Neuroscience, Machine Learning
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jarroddowdall.bsky.social
Including neurons from the Electric Fish and the Bearded Dragon!
Figure 5 from the pre-print showing neuronal waveforms recorded in 4 species, the mouse, pig-tailed macaque, electric fish, and bearded dragon. The bottom panel shows the footprint (spread) across the probe of the neurons recorded in all 4 species, and indicates roughly 10-12% of neurons had a spread less than 20 microns in the macaque, mouse and bearded dragon. Whereas 48.7% of the recorded units in the electric fish had a spread less than 20 microns. This figure demonstrates that the high-density NP Ultra is able to record units that previous Neuropixels probes are not.
August 25, 2023 at 2:04 AM
jarroddowdall.bsky.social
Neuropixels Ultra!

Although, the NP Ultra only records from 384 sites simultaneously, it is impressively dense boasting 1333 sites/mm (6-um pitch).

Ultra-high density electrodes improve detection, yield, and cell type specificity of brain recordings. www.biorxiv.org/content/10.1...

#neuroscience
Figure 1. Neuropixels Ultra probes have a considerably denser site layout over a smaller spatial range. A (left), Schematic of a complete NP Ultra probe, including headstage and flex cable. (right) Scanning electron microscope images of an NP Ultra probe tip (top) and individual contacts (bottom, top inset) C, Comparison of waveforms as measured on all three probes. The NP Ultra panel (right) shows the mean waveform of a unit recorded in mouse primary visual cortex; this waveform was spatially re-sampled to approximate the signal on the 12 x 12 µm grid for NP 1.0 (left) and NP 2.0 (middle) site configurations. This figure illustrates that the increased recording site density of NP Ultra allows the recording of neurons that may be missed by previous probes, which have a larger spacing between sites.
August 25, 2023 at 1:13 AM
jarroddowdall.bsky.social
Controlling neurons with neurons!

"Implementation and testing of a biohybrid transition microelectrode array for neural recording and modulation." https://www.biorxiv.org/content/10.1101/2023.08.08.552362v1

New tech for neuroprosthetics, and manipulating neurons more physiologically. #neuroscience
Schematic of the functional principle of the biohybrid device. Neurons that are trapped in a silicon-based chip’s micromachined golden wells project their neurites through hydrogel-filled microchannels of 4x4 polymer shanks towards the brain tissue. At the interface between the neuron culturing hydrogel and the brain tissue, the tissue-engineered neural networks connect to the brain’s neural network through synapsis. A fluorescent confocal image of the Calcein-AM stained neurons reveals their neurites’ projections through the implant’s polymer shafts.
August 14, 2023 at 5:42 PM