Emotion is the product of unconscious evaluation of a stimulation

Feeling is the conscious reflection of the evaluation

emotion stimulates the thalamus, projecting to hypothalamus

1.hypothalamus (body response)

2. Anterior thalamus -> sensing

3. cingulate cortex -> feeling

4. Hippocampus -> readout

5. hypothalamus (body response)

individual components have different goals.

peripheral component -> hypothalamus controls blood pressure, heart rate

Conscious experience -> cortex, cingulate, orbitofrontal, and prefrontal 

Amygdala -> unconscious evaluator and coordinator

archicortex (very old)

small granule neurons, and large pyramidal neurons

3 layer organization in allocortex (molecular layer, cellular layer, polymorphic layer, which contain axons, soma, and interneurons respectively)

1. Glutamatergic input from entorhinal cortex synapse on dentate gyrus (perforant path)

2. Granule cells project to CA3 via mossy fibers

3. CA3 projects to CA1 pyramidal neurons via schaeffer collaterals

4. CA1 projects back to Entorhinal cortex

Basolateral division -> router to/from cortex, takes input from senses+thalamus and memory from hippocampus

Medial Division -> output stage of amygdala

Medial Division to Bed Nucleus of Stria Terminalis

Ventral Amygdalofugal pathway projects away to the prefrontal cortex, thalamus, hypothalamus, (main output stage)

ventral surface of frontal lobe (above eyeballs)

widely interconnected between cortex, includes anterior cingulate cortex

takes highly processed sensory info, sends it to limbic nuclei (medial receives less sensory inputs)

Responsible for reward association. Looks very variable across people (sulcus and gyrus are different, heterogeneous)

electrical stimulation of the amygdala is associated with fear.

damage to amygdala produces flat affect

fMRI of emotional recognition tasks cause amygdala to activate

the amygdala is associated storing, acquiring, and expressing the fear response.

Neutral stim + pain -> physiologic response

then

Neutral stim alone -> physiologic response

LeDoux, mapped fear learning circuit.

Superior part of amygdala responded to the electrical shock

Middle part responded to both the tone and the shock

Inferior part responded to the tone only

No blood pressure increase, but the freezing function is still intact.

Disrupts only the learned response, unconditioned responses were unaffected.

Blood pressure increases, but freezing diminishes

The lateral hypothalamus is responsible for autonomic responses, and the central gray is responsible for the conditioned behavior

1. Amygdala and hippocampus complement each other with memory

2. Memory is enhanced with arousing stimuli

3. Emotion influences attention and perception

4. Extincition of memories involves the ventromedial prefrontal cortex.

Affect

Lobotomized patients show flat affect

New memories are initially mutable and sensitive to disruption before consolidating into stable memories. Lateral and basal parts of the amygdala are associated with this storage. Anisomycin prevents protein synthesis in these regions -> rats don't become fear conditioned.

Infusion of anisomycin while recalling these memories, lessens the response to these memories.

erase the emotional reaction to a memory, instead of the memory.

In PTSD patients, beta-blockers are given to prevent protein synthesis.

Extinction -> learned response cortically, so that the information isn't ever stimulating the amygdala (good for phobias)

Reconsolidation blockade -> the amygdala is trained not to respond as significantly to frightful stimuli