Download 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?