MiniScope

MiniScope

Here are some improvements to the MiniScope Project, allowing for single cell resolution of awake behaving animals.


Project updated 31.January.2018. Check out the Slick Passive Electrical Commutator. It aids in recording of freely behaving animals by allowing for the wires to spin. It applies to projects outside of the Miniscope, but was designed specifically for the Miniscope. Project updated 19.October.2018 to Rev13. Improvements include backwards compatibility for this system to directly fit into the baseplate of the Machined Head Scope. The optics can much easier be dissassembled for cleaning. A new wire holder can hold the coaxial cable in the center of the PCB to minimize possible damage. The trainer increased in height (to maximize the moment arm) such that the animal will train at the most weight on their head. And the trainer now incorporates the sizes of the PCB. If you need older revisions, poke around the GitLab site or email us.


Here are some project ideas to help advance the amazing MiniScope project. Single cell resolution on behaving animal on the cheap? Yes plz.


3D Printed Head Mount MiniScope

Head Mount

I redesigned the Head Mount system to allow for 3D printing. Unless you are super crazy good (like, world class), FDM printing will not be the way to go. microSLA or Polyjet would be the way to go. I have successfully printed these with a Projet1200 (set to Green resin settings) using Deep Black Resin from FunToDo. Of course, this voids the warranty of the Projet, but the resin is over 10X less expensive, and you get to understand and play with the properties of the resin. Want to find out how to do this and how to fix the resin vats? Shoot me an email. This resin reportedly has less autoflourescence than Delrin.

3D Printed

All components fit with the original PCB, LED, and filters and use the same screws. The walls are thicker, because this plastic doesn’t seem to block light as well, but the entire assembly is only .1 grams more. It includes tick marks so you can know the height you have set the camera at. It has a smaller footprint, and therefore does not fit on the previous MS_Holders.

Don’t have a microSLA printer? Support the ONE Core and order though us!!!! Or use an inexpensive outside 3D printing shop. Rosenberg Industries is aware of ONE Core projects and requirements and has proven success with ONE Core projects.

Head Mount Explosion

File File Type
BasePlate ipt
BasePlate stl
Cover V13 ipt
Cover stl
Faceplate ipt
Faceplate stl
FocusSlider ipt
FocusSlider stl
MainBody ipt
MainBody stl
Protector ipt
Protector stl
Trainer ipt
Trainer stl
Wireholder ipt
Wireholder stl

New components/considerations: The BasePlate is now interchangeable with the machined system. Use either BasePlate to fit either MainBody. This requires a thin wall, so therefore the magnets will no longer press fit it. You will be required to glue them in.

The MainBody has several holes on the side. To hold onto the grin lens, use a 0-80 set screw into the bottom hole. This may be required for use with future, longer grin lenses. Protect the Grin Lens from getting marred by the set screw by covering it with shrink wrap. The rest of the new holes in the BasePlate are for ease of dissassembly. Previously, if a spec of dirt got onto the optics, you might have to dissassemble the whole thing to get at it. But that was difficult, and I broke a few filters trying to get it out. Now you can just push the filters out with these holes. Block light from entering these holes when not in use with biosafe, form-able, light blocking material: halloween makeup. Black tooth wax is typically used to make it appear that you are missing a tooth, but we can use it for cell specific, single cell, neuronal firing imaging! Seriously!!! It easily fills these holes, can easily be removed, blocks light, is safe enough for humans, never drys, and is dirt cheap.

holes

The WireHolder can be screwed on top of the PCB and can hold the coaxial cable. Previously, the coaxial cable would get damaged because the animal could hit it against the walls of a cage. Simply fold the wire through this part, screw it down, and put a dab of hot glue to affix the wire to the WireHolder (hot glue will hold, but can also come apart easily).

The Protector can be placed on top of the PCBA for even MOAR protection. This additional weight may not be great for mice, but may be required for larger, more aggressive animals (prairie voles). It can be assembled with the given screws. Consider throwing a dab of hot glue on top to hold the coaxial cable better.

I’ve also included a ‘trainer’ scope that has the overall shape of the system, but doesn’t require the other components. It is set for the maximal moment arm that the product could produce, to train the animal at the hardest setting. Glue some weight (washers) up on top to replicate that of the PCB, glue or press fit in the magnets, and boom, now you can train the animal without risk of damage of the actual system.

Assembly and Ramblings: The cooner coaxial cable is crazy expensive. Alpha Wire 9438 WH033 works just as well at a fraction of the price. Or, if you are using a larger animal, save yourself some head ache and go with a larger cable. The Jonard Tools ST-450 works well to strip these.

Because these parts are 3D printed, you will not have to clean the machined burrs out. But, because these are 3D printed, there may be some slight sagging of the very small holes. It is a good idea to clean them out prior to using any of the screws. Use a McMaster 2546A23 tap to hold onto #61-80 wire gauge drill bits to clean up the holes, if necessary.

zoom


DAQ housing

DAQ

The original DAQ housing, at the time of writing, has errors in the STL (I couldn’t get it into my slicing Software). Here is a quick update to the housing that emphasizes minimal print volume and writes the DAQ inputs and outputs within the housing. It prints well with nGen, 40% infill, no supports necessary. Assemble with pan head M3 screws, 20 mm long (McMaster 92005A128), no nuts or glue is necessary. The current DAQ PCB only has one through hole for seating. This is…odd, but this design conforms.

There is a new design for allowing for a BNC Connector so that you can trigger the camera with a TTL. More below.

File Description File Type
Redid DAQ Enclosure Bottom.ipt DAQ Enclosure Bottom ipt
Redid DAQ Enclosure Bottom.stl DAQ Enclosure Bottom stl
Redid DAQ Enclosure Top.ipt DAQ Enclosure Top ipt
Redid DAQ Enclosure Top.stl DAQ Enclosure Top stl
Redid DAQ Enclosure Bottom TTL.ipt DAQ Enclosure Bottom TTL ipt
Redid DAQ Enclosure Bottom TTL.stl DAQ Enclosure Bottom TTL stl
Redid DAQ Enclosure Top TTL.ipt DAQ Enclosure Top TTL ipt
Redid DAQ Enclosure Top TTL.stl DAQ Enclosure Top TTL stl

Don’t have an FDM printer? Support the ONE Core and order though us!!!! Or use an inexpensive outside 3D printing shop. Rosenberg Industries is aware of ONE Core projects and requirements and has proven success with ONE Core projects.


Trigger Input

“In the 3.2 version of the DAQ PCB the “trigger in” port isn’t one of the 2 ports that come assembled with an SMA connector. Here, http://imgur.com/a/hgzua, is a picture of where the connections of this port are located. You can solder one of these coax cables, https://www.digikey.com/products/en?keywords=0897611670, to the 2 pads and then run it out of the DAQ Box.” -Daniel Aharoni June 15th, 2017, MiniScope forum

I have made an update to the DAQ housing to reliably hold a BNC Connector (TE Connectivity PN 5227726-1, Mouser 571-5227726-1). To assemble, cut and strip some 22 gauge single core wire. Take the BNC connector and bend out the ground pin a bit. Hook the ground wire through the hole and pinch it tight with pliers. Insert the signal wire in the center and pinch close with pliers.

BNC Solder

Hit it with a lot of heat and then some solder. Isolate the connections with some shrink wrap.

BNC Shrink

Then, be sure to feed the assembly through the housing and the nut before you solder the wires to the PCBA. Else, you have to unsolder it to get it to assemble, not that I would know…

TTL Over TTL Assembled


Miniscope Holders

Stereotaxic Holder

How do you hold the MiniScope during implantation? There are holders out there for current commercial imaging microscopes, but they are expensive (!). Hold your Miniscope with these inexpensive FDM 3D printed holders! They assemble with 6-32 1/2” long Screws and nuts (McMaster 91772A148 and 90480A007), and do not require any glue or otherwise to assemble. Three flavors are given: one that simply attaches to a basic 6mm stereotaxic rod at 90 degrees, another that attaches to a ball on the end of a 6 mm rod (place into your stereotaxic equipment), allowing you some rotation around two axis (McMaster PN 6402K12), and one that attaches to the 3D printed Miniscope (see below). Some researchers needed a cup to increase the diameter of the rod to fit into their stereotaxic equipment, so that is there as well. You can keep wires out of the way by fitting them into the holes on top of the parts. I like nGen, 40% infill (maybe more on the ball system), no supports necessary.

Note: In order for the system to accept the ball and still be flexible, the parts are kind of thin. When you try to insert the ball, you may break the parts. I’ve found it helpful to print it out, then hit it quick with a heat gun before I insert the ball, and then let it cool. I hit it with the heat gun again, and pinch it snug around the ball with my fingers, thermoplastics and all.

File Description File Type
Stereotaxic Miniscope Holder Hold the Miniscope at 90* ipt
Stereotaxic Miniscope Holder Hold the Miniscope at 90* stl
Stereotaxic Miniscope Holder with Angle Hold the Miniscope at a variety of angles ipt
Stereotaxic Miniscope Holder with Angle Hold the Miniscope at a variety of angles stl
Stereotaxic Miniscope Holder with Angle 3D Design Hold the Miniscope at a variety of angles ipt
Stereotaxic Miniscope Holder with Angle 3D Design Hold the Miniscope at a variety of angles stl

More stereotaxic probes can be found here.

Don’t have an FDM printer? Support the ONE Core and order though us!!!! Or use an inexpensive outside 3D printing shop. Rosenberg Industries is aware of ONE Core projects and requirements and has proven success with ONE Core projects.


ONE Core acknowledgement

Please acknowledge the ONE Core facility in your publications. An appropriate wording would be:

“The Optogenetics and Neural Engineering (ONE) Core at the University of Colorado School of Medicine provided engineering support for this research. The ONE Core is part of the NeuroTechnology Center, funded in part by the School of Medicine and by the National Institute of Neurological Disorders and Stroke of the National Institutes of Health under award number P30NS048154.”