Thursday, March 20, 2014

140319 - Coupling

Ok from a couple of swim bouts we can identify a bunch of swim neurons.

Then can target and record during swimming with ephys

Here is 208, colored by its phase:
I gave 208 a little stim near the 45s mark, but didn't seem to effect swim pattern. The DP nerve being shown is not from the same ganglion, but the phases are corrected.

And can target some other cells, 152, and 154:
Top - electrodes are recording from 152 and 154. Bottom, ephys of 152 and 154 shows oscillations during swim.

Here is the contralateral 154, and 153:

(This is much later in the experiment. The ganglion is dying and the VSD signals are getting weaker. The 153 oscillation is typically much much larger.)

Now we can excite 152 and see its functional coupling:

A. 152 (white) and 154 (cyan) are targeted with ephys. 154 is excited with 0.5 nA of current in a 1Hz square wave. 154, CV and 208 show inhibitory (out of phase) responses to 152 excitation. B. The coherence of voltage signals computed at 1Hz frequency. Red means in phase, cyan means out of phase. The colors are mapped onto components and shown on the ganglion in A. C. VSD traces of cells with significant coherence to 152. D. Ephys traces of 152 (red) and 154. (Bridge is over-compensated for 152, so what appears as down is actually up). Inhibitory response of 154 is seen in ephys trace. Dp nerve gets excited from 152 excitation, but no clear behavioral response.

Then we can inhibit the cell and see inhibitory functional coupling:

 A. 152 is inhibited. B. Coherence of VSD signals with 152. C. Traces of cells with sig coherence. D. Ephys of 152 and 154, no clear effect on 154 from inhibtion. Not much happens to DP. 

Oddly, with this it appears that the contralateral CV follows the inhibition in phase, while the ipsilateral CV follows out of phase. Perhaps 152 is electrically coupled to contra CV, and inhibits both CV.

Next, target 154. I ended up getting both bilateral pairs in this experiment.

So the SNR is starting to die, but I think its clear that 154 are connected bilaterally, and they both excite CV. Interestingly, 154 and CV are both in the purple colored phase of swim oscillation, while 152 is blue.

I also tried 153, but by the end the SNR of the VSD was so low that I wasn't confident about anything.

Here's the summary of 152 and 154 from this experiment:

Tuesday, March 18, 2014

140318 - fast network and s cell

Found the S-cell with an electrode and I wanted to check its coupling. I injected 0.4 nA of current at 0.5 Hz and then measured the followers of the S cells. I did the analysis with ICP and made the functional maps based on the coherence between the S cell voltage signal (black traces, cell body highlighted in white), and this was done with different settings.

What stands out as interesting is that the S-cell is strongly coupled to the AP cell, further suggesting that the S-cell and AP cell are part of the fast network. It is also connected to Accessory AP, and potentially another cell in the central packet thats part of the fast network. The green cells that get hyperpolarized seem real, less confident about the blue cells. The top trace uses 50 pcs, the bottom trace uses 130 (I think, maybe 100 or 150). The frequencies examined are from 0.5-0.6 ish.

This data is from x140316-t8.