The new 2nd-generation Linear Microelectrode Array (LMAv2) features an advanced shaft tapering method to provide an extremely thin (<200 µm) shaft diameter along the functional length of the LMA tip while allowing for up to 32 channels.
The LMAv2 provides a smoother, sharper penetrating tip while retaining the signature customizability of the original LMA.
Additionally, the tip of the LMAv2 itself can be set as a recording contact, eliminating the minimum tip-to-contact distance limitation of many other probes.
- Long-tapered shank keeps the shaft thin (< 200 µm where the contacts are located, while widening a distance from the tip to provide for more contacts and a more rigid probe.
- Sharper, less abrupt tip shape than the original LMA improves tissue penetration.
- Hard, durable tungsten tip that can itself be set as a recording contact, or ground or reference.
- Each shank may contain 4 to 32 contact sites.
- Contact sites may be positioned anywhere on the shaft surface (minimum spacing 75 µm), allowing for endless possibilities (helices, rings, clusters, opposing columns, etc) .
- Contact sizes 15, 25 µm.
- Multiple contact sizes allowed in each shaft, allowing researchers to mix and match functionality at different depths.
- Platinum/iridium contacts.
- Platinum Group EPIC coating is available, reducing impedance by an order of magnitude for the same sized contact.
- 3D arrays of multiple shanks are available.
- Fixed or flexible-cable configurations available.
Single Unit - LFP
LMAv2 - Single Shank
LMAv2 - MULTI SHANK
LMAv2 - FLEXIBLE CABLE
The LMAv2 probe is now our linear electrode array of choice for acute neurophysiology in behaving macaque monkeys. We record from cortex and do not use a guide tube. The LMAv2 is stiff enough to penetrate through the silicone membrane that we implant in place of the native dura. Signal quality from the LMAv2 is excellent on most channels and consistent across sessions. We have used some LMAv2 arrays in over 30 penetrations and they are still delivering excellent results for both spikes and local field potentials. Our experience with the engineers at Microprobes has also been outstanding. With their expertise and discussions with our group, we now have an LMAv2 that is custom fit to our needs. Thank you Microprobes!
Omar A. Gharbawie Ph.D.Department of Neurobiology; University of Pittsburgh
"Our lab chronically implants tetrodes into the auditory midbrain of rabbits to study hearing. We wanted to increase our yield by switching to linear microelectrode arrays with more channels, but it was difficult to find probes that were compatible with our microdrive setup and had the length needed to reach the midbrain. We chose the 16-channel LMAv2 because it was incredibly customizable and could work with our current microdrive. Using custom 3D-printed parts, we adapted our NeuraLynx 5-drive setup to use the LMAv2. With this setup, we can reach the 14mm depth of the auditory midbrain and sample at different depths. We have implanted a probe for about two months and have gotten high-quality single-unit midbrain recordings on 8/16 channels. We estimate the probe is about three quarters in the auditory midbrain and as we continue descending, we hope to see even more driven channels. The impedance values of the LMAv2 have stayed constant since implantation, and we are excited to continue collecting data with these probes. After we gather more pilot data, we hope to further increase yield by adding multiple probes.
Johanna, FritzingerNeuroscience graduate student; University of Rochester Medical Center
“My lab needed a multi-site recording electrode that could be chronically implanted at a shallow insertion angle into NHP frontal eye fields. We tried a flexible polyimide electrode, but a linear probe didn’t meet our needs. After talking with MicroProbes, Inc, we settled on the multi-shank LMAv2. The first couple of implants went well, and we were getting units on about 80-90% of the recording sites (16 channel in one implant, 32-channels in the other). That’s when it got interesting. At 3 months post implant, we were still getting units on 13 of the 16 channel implant! At 6 months, we still got units on half of the channels. Today we are approaching 12 months post implant and still getting units on 5 channels, and local field potentials on the original 13 channels that were viable at 3 months. Impedances have been stable since the first couple months. Obviously, this isn’t typical, but on the other implant, we lost implant integrity before we lost recordings on the LMAv2s! This fall I’m looking at up doing more implants in hippocampus and prefrontal cortex, and they will all be LMAv2s.
Robert E. Hampson, Ph.D.Research Associate in the Winrich Freiwald lab at Rockefeller University