Conversation with the e-phys master

Mater: Poke it....

Young Akira: ?

Mater: I said, poke it!

Young Akira: .... (Tap, tap)

Master: Wah was dat? An exhibition? We need EMOTIONAL CONTENT. Try again!

Young Akira: .... (TAP, TAP)

Master: I said EMOTIONAL CONTENT. Not anger! Now, try again!
With meeee!

Yong Akira: .... (Tap! Tap!)

Master: Ho, ha! That's it! See, it's bursting! How did it feel to you?

Young Akira: Well, let me see...

Master: (Whap!) Don’t think! FEEEEEL. It is like a finger pointing a way to the neuron!
(Whap!) Don’t concentrate on the electrode or you will miss all that heavenly action potential! Do you understand?

Young Akira: I see, sir... (Bows)

Master: (Whap!) Never take your eyes off your prep!

Prolonged presynaptic posttetanic cyclic GMP signaling in Drosophila motoneurons

By Dinara Shakiryanova and Edwin S. Levitan
PNAS 105 (36): 13611-13613

1) The activity of cyclic nucleotide activity is first shown at the terminal. It is cGMP, not cAMP.
2) NO generation and activation both occur in the presynaptic terminal
3) It is surprisingly long lasting.


FRET-based cAMP imaging showed a Ca-dependent sustained increase of cAMP (or cyclic nucleotide) after a brief activation of synapse (fly neuromuscular synapse).

However,
1) Ca-dependent increase of cyclic nucleotide (cAMP). Both extracellular and RyR-mediated.
But,
- Ca-stimulated AC mutant has no effect.
- cAMP-specific PDE mutant has no effect.

2) This is cGMP instead of cAMP?
- GC inhibitor (ODQ) reduced the FRET signal.
- NOS inhibitor and NO scavenger reduced it too.
- Expression of cGMP-specific PDE shortened the signal.
- IBMX indeed extend the cGMP signal duration.

NOS-guanylyl cyclase-mediated presynaptic cGMP synthesis.

ODQ: guanylyl cyclase inhibitor
L-NAME: NOS inhibitor
PTIO: NO scavenger

They don’t show the effect on synaptic strength…

Video games and experiments

Performing a biology experiment is somewhat like playing a role playing video game (RPG). You need to pile a series of success to reach the goal. There are two types of the RPGs. One is the Final Fantasy/Dragonquest- type games, and the other is the Zelda/Metroid-type games.

In the Final Fantasy/Dragonquest-type, all you need to do is to give commands to your character to defeat the enemies and to make him/her stronger and stronger. Tactics and strategies are important. The character will gather a lot of weapons and armors, potions, and dozens of other items in the inventory. The inventory has to be well organized by the player.

On the other hand, games like the Zelda series and Metroid, a player needs to develop his/her own skill and technique to control the character. The player needs to learn how to precisely attack enemies and maneuver quickly from their attacks. Very challenging and even stoic.

I assume those who live on biochemistry and molecular biology may prefer the Final Fantasy/Dragonquest type rather than the Zelda/Metroid type.
I prefer Zelda and Metroid. There I could even feel dopamine being gushed out inside my brain when I defeat the final opponent. I feel similarly when I am having a good result from the electrophysiological experiment.