presentation made at UNIC, Gif-sur-Yvette

1. Gif-sur-Yvette, UNIC, 10/06/2013 Joël Chavas
Electrophysiology, modelling and
electronics
- The GABAA receptor
- Electronic
implementation of a
network

2. Outline
• Effects of the GABAA receptor
• Electronic implementation of a network

3. The GABAA receptor

4. Reversal potential

5. Synaptic activation

6. Cerebellum

7. EGABA, more hyperpolarized for
Purkinje cells than for interneurons

8. Interneurons in the cerebellum: a
mixed excitatory / inhibitory network
B.
EGABA
Vm

9. A conductance to two ions, Cl- and
HCO3
-

10. A conductance to two ions, Cl- and
HCO3
-

11. Cl- inflow and rise of Ca2+
i

12. GABAA activation induces a
depolarization and a rise of Ca2+
i
BK channel
Vo, relative measure of intracellular calcium

13. Mechanisms of an osmotic change

14. More on GABAA receptors?

15. A sparse random graph of computing
units
A sparse random graph of interacting computing units
converges towards the « closest » attractor, which is a cluster
of solutions to the boolean formula
Resolve 3-SAT:

16. A sparse random graph of computing
units
Resolve 3-SAT:
A sparse random graph of interacting computing units
converges towards the « closest » attractor, which is a cluster
of solutions to the boolean formula
Sparse, only local information
⇒ Parallelism
⇒ FPGA, threads, MPI,
HPC, graphical cards

17. Electronic computing, a compromise
between space and time?

18. Emulation, simulation

19. Where to go?

20. Scientific skills
• Electrophysiology
• Biophysical modelling
• Computational neuroscience
• Statistical physics, machine learning

21. Technical skills

22. « Force de proposition »
• pH transients induced by GABAA activation
• A dynamical model of the cerebellum
– How to learn dynamics?
• Use of the right electronics and software tools
to answer scientific questions
– Engineering, always longer (5x) than planned
• Reduce engineering ambitions
• Away from NIH, reuse
• More time for models