1. Interneuron diversity and the cortical circuit for attention
Paul Tiesinga
Computational Neurophysics Lab at UNC
Title art: from the 2005 Science and Engineering Visualization Challenge organized by Science Magazine

2. A “VSD” Experiment Map(s), connectivity:
suppression, facilitation, biased competition, STRFs, synchrony

3. Input to cortex
Output of cortex
LGN

4. 1. Interneurons

5. Interneuron diversity
FFI: PV+/FS
TDI
CR+/CB+
Markram et al (2004) NRN

6. Circuit of CR+ interneurons
Macaque
Meskanaite, CerCor (1997)
Rat

7. 2. Stimulus competition (V4)

8. The model
TDI
TDI
FFI
FFI E E
Column 2
Column 1

9. Picture from Okinawa course website

10. Symbols for Stimulus conditions
Receptive field
Neuron 2 + +
Stimulus location 2
Receptive field
Neuron 1
Neuron 1
Neuron 2
Pref.
stimulus
Nonpref.
Stimulus location 1

11. The model (1250 synaptically-coupled single-compartment neurons with Hodgkin-Huxley-type channels)
Column 1
Topdown: FEF
TDI
TDI 50
FFI
FFI 75
Feedforward: V2 E E
500
TDI: top-down interneuron
FFI: feed-forward interneuron
FEF: frontal eye fields

12. Stimulus competition requires a switch
FFI
FFI E E
Buia & PT,JNP 2008

13. 3. Attention modulation (V4)

14. Task and so on Attend away from receptive field
Attend into receptive field
Salinas & Sejnowski NRN 2001

15. Feature attention + + + + F-att Feature attention TDI FFI E
Attend the feature red (preferred feature neuron 1) + +
FFI
Attend the feature blue (preferred feature neuron 2) + + E

16. Feature attention biases competition

17. Response-gain like

18. Spatial attention + + + + TDI Spatial attention FFI S-att E
Spatial attention to location 1 + +
FFI + +
Spatial attention to location 2
S-att E

19. Spatial attention biases competition

20. Contrast-gain like

21. Hypothesis Feature attention versus spatial attention
Top-down (first) versus bottom-up (later)
Response gain versus contrast gain

22. 4. Back to interneurons

23. Contrast response surface of E-cells
Stimulus competition

24. The FFI always increase their rate with spatial attention

25. With feature attention, FFI rate changes are in opposite direction to those of E-cells

26. 5. Oscillations and synchrony

27. Stimulus competition is signaled by beta oscillations
Stimulus onset
FFI2
FFI1 E2 E1
Buia & PT,JNP 2008

28. In the pair condition, synchrony during feature-attention has a beta and gamma component
TDI E
FFI E

29. Beta vs Gamma
TDI
TDI
Gamma
(ING)
FFI
FFI
Beta (PING) E E

30. Summary
For the first time the responses at the ‘four corners’ under different attention conditions are reproduced using a single, spiking network model (Exp: many).
Two types of interneurons (FFI, TDI) are needed.
During spatial attention the FFI increase their rate, whereas during feature attention they decrease their rate. (Exp: Mitchel et al 2007)
The TDI increase their rate with feature attention and synchronize their home column. (Exp: none)
Strong competition between the two columns leads to beta oscillations, whereas feature attention leads to gamma oscillations. (Exp: Bichot et al 2005)
Hypothesis:
TDI are CR+ (or CB+) double bouquet cells, possibly adapting,
FFI are PV+ basket cells, fast spiking.

31. Experimental confirmation
Monkey model
Task combining feature and spatial attention with same stimulus
Distinguish interneurons from pyramidal cells
Rabies/herpes virus based transsynaptic tracing
Mice model
Interneuron specific promoter coupled to fluorescent protein
Two photon calcium imaging
Develop behavioral task

32. Thanks to Calin Buia (Harvard Medical School) Amelia Cohen (UNC)
Terry Sejnowski (Salk institute)
Jorge Jose (SUNY Buffalo/Northeastern University)