Encoding of conditioned fear in central amygdala inhibitory circuits.
The central amygdala (CEA), a nucleus predominantly composed of GABAergic inhibitory neurons, is essential for fear conditioning. How the acquisition and expression of conditioned fear are encoded within CEA inhibitory circuits is not understood. Using in vivo electrophysiological, optogenetic and pharmacological approaches in mice, we show that neuronal activity in the lateral subdivision of the central amygdala (CEl) is required for fear acquisition, whereas conditioned fear responses are driven by output neurons in the medial subdivision (CEm). Functional circuit analysis revealed that inhibitory CEA microcircuits are highly organized and that cell-type-specific plasticity of phasic and tonic activity in the CEl to CEm pathway may gate fear expression and regulate fear generalization. Our results define the functional architecture of CEA microcircuits and their role in the acquisition and regulation of conditioned fear behaviour.
Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
Stephane
S
Ciocchi
Cyril
C
Herry
François
F
Grenier
Steffen B E
SB
Wolff
Johannes J
JJ
Letzkus
Ioannis
I
Vlachos
Ingrid
I
Ehrlich
Rolf
R
Sprengel
Karl
K
Deisseroth
Michael B
MB
Stadler
Christian
C
Müller
Andreas
A
Lüthi
D000200:Action Potentials; D000679:Amygdala / Q000033:anatomy & histology / Q000166:cytology / Q000502:physiology*; D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D046352:Freezing Reaction, Cataleptic; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009433:Neural Inhibition / Q000502:physiology*; D009434:Neural Pathways / Q000166:cytology / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D005680:gamma-Aminobutyric Acid