Transcript Nature 402
The amygdala modulates prefrontal cortex activity relative to conditioned fear Rene Garcla , Rose-Marie Vouimba , Michel Baudry, Richard F. Thompson Nature 402,294-296(1999) Introduction Question Experiment 1 Experiment 2 Result Discussion Prefrontal Cortex(PFC) •The PFC connects with a vast array of other cerebral structures and itself. • The PFC is dedicated to the emotional behavior, memory, planning, execution of actions and temporal organization of behavior. Amygdala(杏仁核) •The amygdala connect the region concerned with somatic expression of emotion and the neocortical area concerned with conscious feeling, especially fear. • Animals trained in classical conditioning display fear responses, freezing, when they hear the conditioned tone. • Freezing to a conditioned tone is enhanced following damage to the dorsal part of mPFC. • Amygdala is required for both the acquisition and expression of learned fear responses(freezing). Introduction Question Experiment 1 Experiment 2 Result Discussion •Whether the changes(depression) of PFC neurons activity is related to the freezing behavior? •If the damage of amygdala can abolish the changes(depression) of PFC neurons activity? Introduction Question Experiment 1 Experiment 2 Result Discussion • 36 male mice (C57BL/6 JI; 4-6 months; 28-32g) • Electrodes were made of platinum-iridium wires(50μm in diameter), and were positioned in the PFC for recording and in the amygdala for lesion respectively. • The behavior of mice was observed using a video camera monitor system. Neuron activity freezing A: spikes during CI or CS B: spikes during pre-CI-CS period (B-A)/(B+A) A: spikes during CI or CS B: spikes during pre-CI-CS period (B-A)/(B+A) • The changes of PFC neurons activity is related to the freezing behavior. Introduction Question Experiment 1 Experiment 2 Result Discussion PFC Amygdala • • • • Tone-shock association Lesion(4 types) Auditory test(CS only) Amygdala form one side project poorly to the contralateral side • The depression in PFC neuron activity is modulated by amygdala, not the freezing response. Introduction Question Experiment 1 Experiment 2 Result Discussion • The changes of PFC neurons activity is related to the freezing behavior. • The depression in PFC neuron activity is modulated by amygdala, not the freezing response. Introduction Question Experiment 1 Experiment 2 Result Discussion • 為什麼要用conditioned freezing(fear) 當作研究emotion 的題材 1.這是一種比較極端強烈的情緒反應,比較容易觀察 2.這是一種生存上必需的反應,以躲避危險的事物,所以 可以在較低等的生物上看到 • Amygdala會影響PFC的activity,可能是為了在緊急的時 候,先關掉PFC的 decision-making的功能 • Amygdala可以控制PFC的activity,但是否會經過其他的 路徑,而不是直接地控制? • 為何在選取electrical activity時,signal to noise ratio必須 要超過4比1?