Cornering the fear engram: long-term synaptic changes in the lateral nucleus of the amygdala after fear conditioning.
Use-dependent synaptic modifications in the lateral nucleus of the amygdala (LA) have been suggested to be the cellular analog of memory trace after pavlovian fear conditioning. However, whether neurophysiological changes in the LA are produced as a direct consequence of associative learning awaits additional proof. Using microstimulation of the medial geniculate nucleus of the thalamus as the conditioned stimulus (CS), we demonstrated that contingent pairings of the brain-stimulation CS and a footshock unconditioned stimulus lead to enhanced synaptic efficacy in the thalamic input to the LA, supporting the hypothesis that localized synaptic alterations underlie fear memory formation.
Kwon
Jeong-Tae
JT
Department of Psychology, Korea University, Seoul 136-701, Korea.
Choi
June-Seek
JS
D000679:Amygdala / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology*; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004597:Electroshock; D005071:Evoked Potentials; D005239:Fear / Q000502:physiology*; D046352:Freezing Reaction, Cataleptic; D005829:Geniculate Bodies / Q000502:physiology; D008297:Male; D008568:Memory / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000502:physiology*