Interneuron diversity and the cortical circuit for attention

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Interneuron diversity and the cortical circuit
for attention

• Paul Tiesinga
• Computational Neurophysics Lab at UNC
• http//neuro.physics.unc.edu

Title art from the 2005 Science and Engineering
Visualization Challenge organized by Science
Magazine
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A VSD Experiment
Map(s), connectivity
suppression, facilitation, biased competition,
STRFs, synchrony
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Input to cortex
Output of cortex
LGN
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1. Interneurons
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Interneuron diversity
FFI PV/FS
TDI CR/CB
Markram et al (2004) NRN
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Circuit of CR interneurons
Macaque Meskanaite, CerCor (1997)
Rat
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2. Stimulus competition (V4)
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The model
TDI
TDI
FFI
FFI
E
E
Column 2
Column 1
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Picture from Okinawa course website
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Symbols for Stimulus conditions
Receptive field Neuron 2


Stimulus location 2
Neuron 1 Neuron 2
Pref. stimulus
Nonpref. stimulus
Receptive field Neuron 1
Stimulus location 1
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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
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Stimulus competition requires a switch
E
E
E
FFI
FFI
E
E
Buia PT,JNP 2008
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3. Attention modulation (V4)
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Task and so on
Attend away from receptive field
Attend into receptive field
Salinas Sejnowski NRN 2001
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Feature attention
F-att
Feature attention
TDI
Attend the feature red (preferred feature neuron
1)


FFI
Attend the feature blue (preferred feature neuron
2)


E
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Feature attention biases competition
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Response-gain like
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Spatial attention
TDI
Spatial attention
Spatial attention to location 1


FFI

Spatial attention to location 2

S-att
E
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Spatial attention biases competition
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Contrast-gain like
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Hypothesis

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

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4. Back to interneurons
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Contrast response surface of E-cells
Stimulus competition
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The FFI always increase their rate with spatial
attention
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With feature attention, FFI rate changes are in
opposite direction to those of E-cells
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5. Oscillations and synchrony
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Stimulus competition is signaled by beta
oscillations
Stimulus onset
FFI2
FFI1
E2
E1
Buia PT,JNP 2008
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In the pair condition, synchrony during
feature-attention has a beta and gamma component
TDI
E
FFI
E
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Beta vs Gamma
TDI
TDI
FFI
FFI
Gamma (ING)
Beta (PING)
E
E
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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.

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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

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Thanks to

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