Messages

1

System Assembly Troubleshooting / coax wire

« on: December 05, 2016, 07:53:23 PM »

After trying out a few different types of coax wire (Cooner is expensive, and didn't even have the suggested wire), this is pretty much the thinnest wire I've been able to get to work (and only at lengths around 5ft.):
https://www.digikey.com/product-detail/en/alpha-wire/9438-WH033/A9438W-10-ND/6003378

It's pretty cheap at $13/10ft.
Even this wire has unreliable connection (DAQ software goes redscreen soon) at 10ft, but 5ft seems stable (on desk- haven't tried on mouse).

Any other favorite wire suggestions?

2

General Discussion / GCaMP transgenic lines

« on: November 03, 2016, 02:57:16 PM »

Hey guys- anyone using any GCaMP transgenic lines with the miniscope?
I think consensus is that ROSA lines are too weak, but has anyone tried Allen TIGR/TITL or Thy1:GCaMP lines?
And has anyone seen any RCaMP/jRGECO lines yet that work? Might be good to cut down on autofluorescence...

3

Electronics / Re: Ephys over coax

« on: November 01, 2016, 08:05:00 PM »

Yeah, thanks Dan- I figured you guys were working on this. I'm not going to SfN this year but I will think about these problems and communicate over the message board. Not sure if I want to go to the trouble of an Intan chip since I just want LFP for now, but it's cool that the clock speed is similar...

4

Optics / Re: GRIN lense acquisition

« on: November 01, 2016, 07:59:56 PM »

Thanks Dan- have you guys ever tried to get longer lenses and cut/grind your own to size?
I think Ben Grewe said that's what they do in the Schnitzer lab. Maybe we could then just get a big length of the glass together and then just cut off what we need?

5

Electronics / Ephys over coax

« on: October 27, 2016, 10:51:39 PM »

I'm thinking of doing some LFP recording while imaging with the miniscope.
To do this, one could either make a simple unit-gain preamp and run a few wires along with the coax cables, but I think it was mentioned in the miniscope workshop that it might be possible to send an additional signal in spare bandwidth on the same coax as the image data.
So I'm basically brainstorming about how this might work, and feel free to jump in if you have ideas.

Components:
1.) unit gain preamp (SMD opamp, or part of dual/quad)
2.) signal amplification (single-supply opamp, with fixed gain?)
3.) and basic filtering? (another channel of quad opamp, e.g.)
3.) AD chip (SMD package)

This would run into the CMOS board MUX, which would synchronize data read/write with the AD chip.

Main questions:
- what is data rate of coax transmission?
- thus how fast could I sample the LFP?
- how to coordinate reading the amplified LFP on the AD chip with MUX chip
- I think the AD chip might need an oscillator- is there one on the CMOS board I can use for this?
- how to DEMUX the LFP on the DAQ board, and take it into acquisition software

Does this make sense? Does anyone else have any ideas about this?

6

Optics / Re: GRIN lense acquisition

« on: October 27, 2016, 10:23:20 PM »

I couldn't find Edmund's part #64-519
Does this GRIN lens have similar specs to the ones you guys have tried?
http://www.edmundoptics.com/optics/optical-lenses/aspheric-lenses/gradient-index-grin-rod-lenses/64520/