Happy birthday Paul!

It's good to have girls in the lab.
I really thought so when I heard Charuni and Ariana laughing at something about the birthday cake while putting letters on it. I don't know what they were laughing at, but I liked it.

Paul became 50. I am 10 years behind.
He was 41 and I was 31 when I came here. I remember Stefan was 38. Jim was 34.
Now he is 50 and I am 40.




Last week, he said I was doing well on getting good data.
Well, getting new data is like breathing to me.

Dissecting a Little Giant

We use Little Giant Pumps for animal tanks. This pump looks sturdy, but often fails if you don't lube it like every 6 months or so like Harley Davidson. You have to baby-sit it all time. Just like HD, this Little Giant is proudly made in USA.
By the way, Georgia Aquarium uses Iwaki pump, which is more like Honda than Harley Davidson.


Today, I had to shut down one of our tanks to replace the filter. Then, this little giant failed to restart.
So I had to restore it.


This is a tricky part. You need a flat-head screwdriver and a hammer to remove this flip thing.


Water propeller, Motor, Inlet-outlet part, main shaft with fan, end cover, magnet ring



Inside the motor. This needs overall cleaning.

Cause of voltage drifting

Sources of 60 Hz noise can be detected by a piece of tin foil.
Don't forget connecting it to reliable ground.

Drifting of the bath potential level is also a quite common problem.
If it is minor one, you can try re-chloriding the silver wires for the bath ground and for electrodes.

If drift goes by several hundred mV, then it is not just a chloriding issue.
There must be electrical connection between the dish saline and surrounding metallic devices. This happens after saline overflow and spill.
The ground for the amplifier head stage (bath ground) and that for other electrical devices (device ground) are not exactly the same. If the dish saline was connected to both of these grounds, then there would be a voltage drop (= drift).

The joint between the silver wire and the soldered point can produce a strong voltage when it gets wet just like a voltaic cell. The ground wire often sucks up saline and gets wet. If the saline reach the soldered joints, it will cause a huge drift. Do not use a short silver wire for grounding the dish. Keep them dry all time during e-phys experiment.

New Lab

We, Katz lab, and the Neuroscience Institute have moved to the new building near Georgia State MARTA Station.
We are on the 8th floor.


Cool-looking building. Tornado-proof? Probably not.

My rig room has a window. I can see the horizon while poking cells!


Our aquarium is now 30 sec away from the lab. This is great.
I did lots of plumbing work to install new filtering system and protein skimmers. This is a hard work. I have had 3 leakage from various PVC joints I made. One of them was due to a crack that was developed during weekend. By Monday morning, half of the tank water leaked out.

One of the chillers failed because the compressor overload protector had fallen off and disconnected the power. I opened it up the chiller and rewired the circuit to skip this failed protector. Now it is running fine.

I was also in panic when I found the other chiller heated up in the morning. The radiator fan was not running. The water was like hot tub. I opened the chiller and found that the fan blade was stuck by touching the frame. I mended it back and now its working fine like new.

Setting up the aquarium is like buying a new Harley Davidson. You will have trouble after trouble until the machinery gets settled.
I would definitely buy Honda.

Backfill

I did backfills on two Melibe brains. Both appeared very nicely.

My success rate on backfilling is pretty high, almost 100%.
It is simple. All you have to do is to let dye solution touch only the cut end of the nerve you want to fill. And make sure the prep is in healthy condition until fixation. Poor results are mostly due to failure in these two things. It is not because of materials or protocols. It is how you manipulate them.

Plasticity during stroke recovery: from synapse to behavior

Timothy H. Murphy and Dale Corbett
Nature Reviews in Neuroscience 10: 861-872 (2009)

Role of ipsilateral pathways
Although canonical view of sensory and motor processing is that body parts are controlled by neurons in the cerebral hemisphere on the opposite side of the body, ipsilateral pathways are also present.

(although the redundancy of an unaffected cortex and the potential of ipsilateral pathways seem advantageous, the issues of lateralization and function are potentially complex and reflect both the degree of injury and the extent of recovery)

Diffuse connectivity
- surprisingly widespread intracortical connectivity between related regions of the cortex, ...

Location is everyting in cortical physiology
- much like the demand for a vacant lot in Manhattan, ...
- there is intense competetion for available cortical map territory
- How the remapping of lost function is initiated, and how seemingly stroke-compromised circuits in the peri-infarct cortex can compete and win in what is thought to be an activity-dependent process, is unclear.

---

Synaptic learning rules in recovery
synapse-based learning rules could help to create compensatory circuits after stroke (Fig. 3).

Homeostatic plasticity and Hebbian plasticity mechanisms
There are no direct evidence for their contribution in recovery.