Introducing the new V-Probe* multi-site, linear electrode. The V-Probe takes the best of the very popular U-Probe to the next level, while also leveraging the benefits of the redesigned, conical-shaped tip to further minimize trauma to the brain tissue upon insertion. It is exceptionally durable, highly customizable, and often used in acute research with medium to large animals.
The V-Probe is a multi-use, multi-site, linear electrode with recording sites positioned on the side of a sharpened, symmetric cone. Compared with our very popular U-Probe, the cone-shaped tip is believed to result in less trauma to the brain tissue upon penetration by minimally displacing tissue along the track. The new design also permits an electrode site to be placed closer to the tip of the probe.
V-Probes are made in a single-row configuration, with a choice of 8, 16, 24 or 32 channels, in lengths up to 150mm.
The platinum/iridium electrode recording sites are available in 15, 20, 25 and 40µm diameter options. The small electrode site diameter (15µm) enables effective single-unit recording, while a unique etching process of the electrode surface results in lowered impedances without significantly changing the overall surface area of the exposed recording site. The result is a small site suitable for resolving single units coupled with low impedance for a better single-to-noise ratio.
V-Probes also come with the flexibility of integrating up to four fluid channels or optical fibers at specified locations – sites 1-4 illustrated in the 8 channel configuration below. Please see the Technical Spec tab for more information on correct placement.
Like U-Probes, V-Probes are exceptionally robust due in part to their hand-crafted, stainless steel construction (as opposed to silicon), and ability to penetrate deep within the brain. When used according to proper procedures, V-Probes will support many uses over a long period of time. Reusing the exact V-Probe from experiment to experiment is not only economical, but more importantly removes one element of potential variability.
You may also wish to explore other options in Plexon’s family of Specialty Probes, Electrodes and Arrays including our Thumbtack Probe for chronic application with medium to large animals.
The illustration below depicts the anatomy of a standard V-Probe by front and top (connector) view. The 8 channel, single electrode configuration is featured as the example (see page 7 of the V-Probe Technical Guide located in the Resources tab for more details on this particular channel count). Electrode sites are numbered accordingly (sites 1 – 8 from connector to tip).
V-Probes are rather customizable, as outlined in the table below. It is possible that V-Probes may be made outside of the specifications indicated. As such, it is recommended that you discuss your needs with a Plexon Sales Engineer to determine if your unique request may be accommodated.
|Feature||Specifications and Options||Remarks|
|Application||In vivo; acute|
|Channel counts||8, 16 24, or 32|
|Total probe length||30 to 150mm||Length is customizable within range provided; however, the most typical request is 100mm. Total probe length is measured from tip to the connector. The difference between the total probe length and the reinforcement tube length is a minimum of 25mm.|
|Probe OD||185 to 360μm||Probe diameters vary based on the number of electrodes, fluid channels and optic fibers. See the Probe diameter tables found in the Probe Technical Guide under Technical Specifications.|
|Reinforcement tube length||5 to 125mm||Length is customizable within range provided|
|Reinforcement tube outer diameters||460 or 640μm||Probe diameters of 236μm and greater require a 640μm reinforcement tube|
|Electrode construction||15μm Pt/Ir electrode site diameter, circuar shape, HML insulated (polyimide), and secured in medical-grade epoxy||15μm diameter sites are recommended for resolving single units (action potentials).|
|Inter-electrode spacing||50μm, 75μm, 100μm, 150μm, or 200μm along length of probe|
|Distance from tip to the closest electrode site||
|The numbering of the electrode sites is such that channel #1 is closest to the connector. Conversely, the electrode site closest to the tip is the largest channel # on the probe.|
|Stimulation options||Single: Up to four fluid capillaries and/or optic fibers||Single: Able to accomodate up to four fluid capillaries/optic fibers. Must be placed within the half of sites closest to the connector. Examples: four fluid capillaries; or four optic fibers; or one fluid capillary with three optic fibers. The total count of fluid capillaries plus optic fibers may not exceed four.|
|Fluid capillary ID||40μm||Fluid capillaries are slightly offset from the center line of the electrodes.|
|Fluid capillary OD||60μm|
|Optic fiber OD||50μm||Optic fibers are slightly offset from the center line of the electrodes.|
8 channel: CON/8o50m-10P
16 channel: 2x CON/8o50m-10P, CON/16m-V or CON/16o25m-18P
24 channel: 3x CON/8o50 or CON/32m-V
32 channel: CON/32m-V
|All are Omnetics connectors.|
|Lifespan||Robust and reusable with a minimum of thirty penetrations, likely many more|
The V-Probe diameter table below provides the minimum diameters for all electrode, fluid capillary and optic fiber combinations.
Single Electrode Configuration:
|Channels||Fluid Capillaries or Optic Fibers||Minimum Probe Diameter (μm) ^||Minimum distance from tip to 1st electrode (μm)||Reinforcement tube diameter (μm)^|
|8||0, 1||185||300||460 or 640|
|8||2||210||300||460 or 640|
|16||0||185||300||460 or 640|
|16||1||210||300||460 or 640|
|24||0||210||300||460 or 640|
*V-Probes are manufactured by Neuronelektród.
^Batch variation in wire inner diameter may require a larger probe diameter or larger reinforcement tube.
- Grandi LC, Gerbella M. Single neurons in the insular cortex of a macaque monkey respond to skin brushing: preliminary data of the possible representation of pleasant touch. Frontiers in behavioral neuroscience. 2016 May 24;10:90.
- Liu LD, Haefner RM, Pack CC. A neural basis for the spatial suppression of visual motion perception. Elife. 2016;5.