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 neural probe.
V-Probes are made in a single-row configuration, with a choice of 8, 16, 24, 32, or 64 channels, in lengths up to 150 mm.
The platinum/iridium electrode recording sites are available in 15, 20, 25 and 40 µm diameter options. The small electrode site diameter (15 µm) 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 signal-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.
Neural probes can be purchased independently or operated in conjunction with the OmniPlex® Neural Data Acquisition System. Your Plexon Sales Engineer is happy to provide additional information and to assist you in determining what might be the most advantageous neural probe configuration.
*64 Channel neural probes are available in single and stereotrode configuration. 64 Channel probes with a single electrode configuration are available with 50, 75, or 100um inter-electrode spacing. 64 channel probes with stereotrode configuration require 100um or 150um interelectrode spacing.
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, 32, or 64|
|Total probe length||30 to 150 mm||Length is customizable within range provided; however, the most typical request is 100 mm. Total probe length is measured from tip to the connector. The difference between the total neural probe length and the reinforcement tube length is a minimum of 25 mm.|
|Probe OD||185 to 360 μm||Neural 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 125 mm||Length is customizable within range provided|
|Reinforcement tube outer diameters||460 or 640 μm||Neural probe diameters of 236 μm and greater require a 640 μm reinforcement tube|
|Electrode construction||15 μm Pt/Ir electrode site diameter, circular shape, HML insulated (polyimide), and secured in medical-grade epoxy|
|Inter-electrode spacing||50 μm, 75 μm, 100 μm, 150 μm, or 200 μm along length of probe||64 Channel neural probes are available in single and stereotrode configuration. 64 Channel probes with a single electrode configuration are available with 50, 75, or 100um inter-electrode spacing. 64 channel probes with stereotrode configuration require 100um or 150um interelectrode spacing.|
|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 neural 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. |
64 channel neural probes are able to accommodate 1 fluid capillary/optic fiber.
|Fluid capillary ID||40 μm||Fluid capillaries are slightly offset from the center line of the electrodes.|
|Fluid capillary OD||60 μm|
|Optic fiber OD||50 μm||Optic fibers are slightly offset from the center line of the electrodes.|
|Connector interfaces|| |
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
64 channel: 2x CON/32m-V or CON/64f-Samtec
|Omnetics and Samtec 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 tubing inner diameter may require a larger neural probe diameter or larger reinforcement tube.
Our linear probes are extremely customizable, some of our most popular custom options include:
Rotating the connector 90 degrees allows for the headstage to be plugged in from the top which can alleviate spacing issues.
Kinked/Angled Reinforcement Tube:
Probes can be made with a “kink” in the reinforcement tube. Customers specify the angle and the location of this bend. Changing the angle of the reinforcement tube can make it easier to plug in the headstage when recording from brain regions close together.
Up to 4 fluid delivery channels for precise drug delivery can be added to S, U, and V-Probes. The placement of these fluid channels depends on the type of probe chosen. A connector steel tube (360um OD) is pulled over the fluid capillary (60um OD) and polyethylene or silicone tubing can be used to connect to the injection system.
Up to 4 fiber optic lines for optogenetic stimulation can be added to S, U, and V-Probes and intermixed within the recording sites. The placement of these fiber optics depends on the type of probe chosen. Probes will be manufactured with a LC ferrule that can be used to connect to your light source.
You can have the location where the jumper cables connect moved to better fit your experimental designs. For example, jumpers can me moved so that they are accesible from the side.
“Pig-Tail” Connector Design:
The unique pig-tail connector design allows for greater flexibility with site orientation and easier movement of the probe while in the microdrive. The length of the cable between the reinforcement tube and the connector can be customized.