High-density neural probes

Also known as Neuropixels, Neuropixels probe, Silicon neural probes

High-density neural probes are thin silicon shanks with hundreds or thousands of recording sites, such as Neuropixels, that record many individual neurons at once. In mice and rats they have followed the same neurons for more than two months, while in people they have so far been used mainly during brain surgery, where recording yield and probe durability remain limits.

Research and prototypesDemonstratedReviewed 21 Oct 2026
AI illustration · Illustrative scene, not a photograph of the specific device or experiment.

In plain language

Neurons communicate with brief electrical pulses called spikes. To study how the brain works, scientists often place fine electrodes into the brain and listen to these spikes. High-density neural probes are thin, flat shanks made with the same kind of manufacturing used for computer chips. Each shank carries many tiny recording sites along its length, so one probe can listen to many neurons at once.

The best-known example is Neuropixels, first reported in 2017. In mice and rats, two probes recorded hundreds of neurons per probe, and in an awake mouse, two probes recorded more than 700 well-isolated neurons at the same time from five brain regions. A later version was designed to stay in place for months, so the same neurons could be followed over time. In people, the probes have so far been used mainly during brain surgery, when the skull is already open. In these studies, researchers have recorded up to about 100 neurons at once, and more than 200 individual neurons across several patients. The probes are not yet used for long-term recording in people.

Technical explanation

The original Neuropixels probe (Jun and colleagues, 2017) is a single silicon shank about 10 mm long with 960 recording sites along it. Its 384 recording channels can be programmably addressed across these sites, so the array can be used to sample different sites along the shank. The authors reported that the probe records well-isolated spikes from hundreds of neurons per probe in mice and rats, and that two probes recorded more than 700 single neurons at once from five brain structures in an awake mouse. The shank is built on CMOS-compatible fabrication.

Neuropixels 2.0 (Steinmetz and colleagues, 2021) is a miniaturised version with more than 5,000 recording sites. The authors combined the higher site density with newly created data-processing methods that enable automatic post hoc correction for brain movements, so that the same neurons could be recorded for more than two months in animals. According to the abstract, high-quality recordings over long timescales were reliably obtained in mice and rats in six laboratories. Spike sorting, the step that assigns each recorded spike to a single neuron, is a separate processing step that the probe papers describe.

In human studies, the probe is inserted into cortex during surgery in which the skull is already open for another clinical purpose. Paulk and colleagues (2022) reported over 200 well-isolated cortical single units across participants and described eight separable single-unit classes that differ in firing rates, locations along the array, waveform spatial spread and modulation by local field potentials. Chung and colleagues (2022) reported up to about 100 simultaneously recorded single units and found that movement of the electrode array was strongly linked to lower yield. A 2025 series of 56 patients at one centre found at least one single neuron in 47 cases, with success rising with experience. In the same series, three probe fractures occurred in the early cases. Linking recorded activity to cell type in people remains unresolved, because genetic labelling methods used in animals are hard to apply to humans (Lee and colleagues, 2024).

What the evidence says

Each statement is typed by the strength of its evidence and linked to the source that supports it.

Demonstrated Shown in a published experiment, test or shipping product.

The original Neuropixels probe has 384 recording channels that can address 960 recording sites along a 10 mm shank, and recorded hundreds of neurons per probe in mice and rats.

Sources: [1] · Abstract

Using two probes, more than 700 well-isolated single neurons were recorded simultaneously from five brain structures in an awake mouse.

Sources: [1] · Abstract

Neuropixels 2.0 has more than 5,000 recording sites and, with newly created data-processing methods that enable automatic correction for brain movements, allowed the same neurons to be recorded for more than two months in animals.

Sources: [2] · Abstract

In intraoperative recordings from human cortex, a Neuropixels variant captured more than 200 well-isolated single units across participants.

Sources: [3] · Abstract · medium confidence

Intraoperative Neuropixels recordings in a 56-patient series at one centre yielded at least one single neuron in 47 cases (83.9%), with success rising from 40% in the first 10 cases to 55% in the first 20.

Sources: [6] · Results

In the same 56-patient series, three probe fractures (5.4%) occurred, all within the first six cases and all under monitored anaesthesia care, and no surgical or medical complications were reported.

Sources: [6] · Results

In ultrahigh-density Neuropixels recordings in neurosurgical patients, prefrontal neurons were found to encode detailed phonetic structure and syllable segmentation before speech.

Sources: [5] · Abstract · medium confidence

Reported, unverified Stated by a company or team but not independently confirmed.

Lee and colleagues describe linking recorded human neurons to their molecular cell type as a fundamental and unresolved challenge.

Sources: [7] · Discussion · medium confidence

Proposed A design or plan that has not yet been built or tested.

Khanna and colleagues state that these neurons demonstrate a cellular process that can support the production of speech in humans.

Sources: [5] · Abstract · medium confidence

Speculative An idea or possible use. Not evidence of anything.

Chronic recording of the same human neurons over months or years is listed as a desirable goal for human probes and has not been shown in people; same-neuron tracking over months has been shown in animals.

Sources: [7], [2] · Introduction

Limitations and open problems

  • Most human recordings are acute and made during surgery, so they last minutes rather than months. Lee and colleagues (2024) describe chronic recording in people as a goal, not a demonstrated result.
  • Recording yield varies widely. In a 56-patient single-centre series, 9 cases produced no single neurons, and all of these occurred within the first 20 cases (Chung and colleagues, 2025).
  • Probe fractures occurred in 3 of 56 cases (5.4%), all within the first six cases and all under monitored anaesthesia care (Chung and colleagues, 2025).
  • Tissue safety data are thin: histology was available from one patient, so the injury findings cannot be generalised (Chung and colleagues, 2025).
  • Movement of the electrode array was strongly linked to lower recording yield, which limits how many neurons can be held (Chung and colleagues, 2022).
  • Linking recorded neurons to their molecular cell type is an open problem in humans (Lee and colleagues, 2024).

Possible future uses

Speculative

Ideas, not predictions. None of these has been demonstrated.

  • Decoding intended speech in people with paralysis from single-neuron signals, building on the speech-related neurons reported in the prefrontal cortex (Khanna and colleagues, 2024).
  • Mapping neuron-level activity during surgery to help surgeons plan the extent of tissue removal.
  • Long-term tracking of human neurons over months to study how memory or disease changes activity, if future probes can be kept stable in people.

Timeline

  1. 1 Nov 2017Jun and colleagues report Neuropixels in Nature: 384 recording channels addressing 960 sites, hundreds of neurons per probe in mice and rats, and more than 700 single neurons from two probes in an awake mouse. Sources: [1]
  2. Apr 2021Steinmetz and colleagues report Neuropixels 2.0 in Science, with more than 5,000 recording sites and recordings of the same neurons for more than two months in animals. Sources: [2]
  3. 31 Jan 2022Paulk and colleagues report more than 200 well-isolated cortical single units from human participants during intraoperative recordings. Sources: [3]
  4. 8 Jun 2022Chung and colleagues report up to about 100 simultaneously recorded single units during human surgery in Neuron, and link array movement to lower yield. Sources: [4]
  5. 31 Jan 2024Khanna and colleagues report prefrontal neurons that encode phonetic and syllable structure before speech, using ultrahigh-density Neuropixels recordings in neurosurgical patients. Sources: [5]
  6. 29 Aug 2025A 56-patient case series from one centre reports single neurons in 47 of 56 cases and three probe fractures, published in the Journal of Neurosurgery. Sources: [6]

Futures this could help bring about

AI illustration
How far away?

Brain-computer interfaces for everyday use

Pilots · 4 of 8 steps done

Glossary

Spike
A brief electrical pulse produced by a neuron when it fires.
Single unit
The spiking activity of one neuron, separated from the activity of others recorded nearby.
Spike sorting
Software and manual checks that assign each recorded spike to the neuron that produced it.
Shank
The thin, flat part of a silicon probe that is inserted into brain tissue and carries the recording sites.

Sources

  1. peer reviewed paper
    Fully integrated silicon probes for high-density recording of neural activity
    Jun JJ, Steinmetz NA, Siegle JH et al.. Nature, 1 Nov 2017. DOI: 10.1038/nature24636. Accessed 21 Oct 2026.
  2. peer reviewed paper
    Neuropixels 2.0: A miniaturized high-density probe for stable, long-term brain recordings
    Steinmetz NA, Aydin C, Lebedeva A et al.. Science, Apr 2021. DOI: 10.1126/science.abf4588. Accessed 21 Oct 2026.
  3. peer reviewed paper
    Large-scale neural recordings with single neuron resolution using Neuropixels probes in human cortex
    Paulk AC, Kfir Y, Khanna AR. Nature Neuroscience, 31 Jan 2022. DOI: 10.1038/s41593-021-00997-0. Accessed 21 Oct 2026.
  4. peer reviewed paper
    High-density single-unit human cortical recordings using the Neuropixels probe
    Chung JE, Sellers KK, Leonard MK. Neuron, 8 Jun 2022. DOI: 10.1016/j.neuron.2022.05.007. Accessed 21 Oct 2026.
  5. peer reviewed paper
    Single-neuronal elements of speech production in humans
    Khanna AR, Muñoz W, Kim YJ et al.. Nature, 31 Jan 2024. DOI: 10.1038/s41586-023-06982-w. Accessed 21 Oct 2026.
  6. peer reviewed paper
    Experience and safety of intraoperative Neuropixels: a case series of 56 patients
    Chung JE, Xu D, Greicius QR. Journal of Neurosurgery, 29 Aug 2025. DOI: 10.3171/2025.4.JNS241162. Accessed 21 Oct 2026.
  7. review article
    Large-scale neurophysiology and single-cell profiling in human neuroscience
    Lee AT, Chang EF, Paredes MF. Nature, 19 Jun 2024. DOI: 10.1038/s41586-024-07405-0. Accessed 21 Oct 2026.

Revision history

3 changes since this profile was created.

Changes on 21 Oct 2026
Published on owner instruction (content loop iteration 59)0949756
Sources and claims re-checked against originalsfbb434c
Initial profile drafted from primary sources7e66249