Pfaus talk

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Revised Syllabus
i.e. only material covered in lecture will be on
examine
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Psy 111 Basic concepts in Biopsychology Lecture
16 Neurobiology of Emotions
Website http//mentor.lscf.ucsb.edu/course/fall/p
syc111/
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Objectives

• Define the subjective experience and expression
  components of emotions.
• Describe the Cannon-Bard and James-Lange theories
  of emotions, related evidence, and modern
  reconciliation of the two theories.
• Define the limbic circuit including the
  structures that comprise it and the major inputs
  and outputs.
• Illustrate the response of the human amygdala to
  facial expression.
• Describe the major inputs to the amygdala and
  the subdivisions of the amygdala.
• Describe the roles of specific parts of the
  amygdala in the auditory conditioning. How do
  these specific parts relate to output pathways
  and different types of responses?
• Describe contextual conditioning and the role of
  hippocampus-amygdala interaction in this process.
• Describe the anatomical connection of the
  prefrontal cortex to the limbic system and its
  potential role in emotional responding.
• Define the concept of valence and salience.

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What are emotions?
Lock, Stock and Two Smoking Barrels (1998) Big
Chris It's been emotional.
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What are emotions?
Emotions subjective experiences arising from
environmental stimuli. Emotions are largely
characterized by Subjective Experience a.k.a.
feelings which includes the cognitive label that
we ascribe to them. Emotional experiences also
have defined Emotional expressive i.e.
expressive components are overt observable
patterns. Emotional experiences are associated
with physiological correlates including hormonal,
autonomic, and neural responses/states.
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Emotional Expression
Emotions are associated with characteristic
expression patterns (i.e. somatic muscle
activation) which include facial and body
postures that convey social information to
others. -Evolutionary value?
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Somatic NS Emotional Expression
Remember some skeletal innervation is under
involuntary control.
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Early Theories of Emotional Experience
Cannon-Bard Theory
Sense/Perceive -gt Experience -gt Expression
Consistent with -intuitive notion about emotions
and -evidence that thinking of emotional
experiences induces emotional expression (e.g.
increase adrenalin, heart rate, etc).
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Early Theories of Emotional Experience
James-Lange Theory
Sense/Perceive -gt Expression -gt Experience
Not consistent with intuitive notion about
emotions but what about experimental evidence to
support that somatic responses influence
emotional experience
But is there evidence for this???? i.e. does
arousal impact emotional experience?
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Subconscious Emotions Expression without
Experience.

• Perception of angry face can be masked by neutral
  face.
• Conditioned emotional expression are still
  manifest when perception is absent.

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Sympathetic Arousal influences Emotions
The Capilano Bridge Experiment
Also, injections of adrenalin evoke feelings in
the absence of obvious environmental stimuli.
Stress responses (presumably due to autonomic
afferents/feedback) can impact the emotional
experience.
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Spinal Lesions and Emotions
Higher the lesion, the greater the reduction in
emotional experience (i.e. blunted affect) which
correlates to reduced peripheral autonomic (
somatic) input.
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Vascular (temperature) function Emotions

• Blood flow contributes to brain temperature and
  is activated by ANS (e.g. during stress).
• Raising brain temperature biases emotional
  experience to anger.
• Cooling brain temperature biases emotional
  experience to happiness.

hot- versus cool-headed actually impacts
emotional experience!
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Early Theories of Emotional Experience and
Expression.
Cannon-Bard theory- argues that the feelings of
fear are evoked by a stimulus and produces a
physiological expression. James-Lange theory
argues that physiological arousal are triggered
by a stimulus and feelings are the cognitive
labels that we impose upon the arousal.
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Recent Theories of Emotional Experience
Modern theories of emotionality propose
convergence of cognitive and somatic responses
(expression) for perception of emotional
experience. Involves parallel system for
experience and expression (with interaction
between systems).
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Limbic Circuit Connectivity.
Hippocampus/ Amygdala
The Papez circuit first provided a framework for
emotional expression/experience consisting
of interconnected limbic structures with
extensive neocortical input and outputs from the
hypothalamus.
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Human Emotions Amygdala
Angry or fearful faces activate amygdala
Happy faces activate amygdala in some studies but
not others may involve contextual factors
???
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Amygdala Emotions

• Amgydala displays highest activation when mixed
  emotions are present.
• Indicating amygdala is sensitive to both positive
  and negative emotional expression.

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Paradigm for behavioral neurobiology of fear.
Key is to examine the emotional expression in
response to conditioned stimuli.
Phase 2 Expression of learning
Phase 1 Learning (next day)
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Conditioned Fear.
Discreet Conditioned Cued Fear Phase 1 pair
discreet cues (light tone) with
footshock. Phase 2 present discreet cues in
absence of footshock and measure emotional
expression (freezing). Acquisition and
Expression of this learned response is dependent
upon the amygdala.
Freezing
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The Amygdala

• Amygdala is an integral part of the limbic
  circuitry.
• Extensive multimodal inputs from association
  cortex and hippocampus
• Extensive outputs to prefrontal cortex, nucleus
  accumbens, and hippocampus.

Distinct nuclei of the amygdala perform distinct
processes in conditioned fear.
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Amygdala Circuitry fear Conditioning.
CS conditioned stimulus US unconditioned
stimulus LA lateral area, B basal nucleus,
CE central nucleus CG central grey (brain
stem) RF reticular formation PVN
periventricular nuc of hypothalamus DMS
diffuse modulatory systems (e.g. dopamine,
serotonin, norepinephrine). Note LA B BLA
basolateral nucleus.
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Amygdala and (Conditioned) Fear Expression
Endocrine
(freezing)
Conscious Behavioral Reactions
Basolateral Amygdala is where the association of
US CS is encoded (i.e. site of neuroplasticity
where CS becomes meaningful) and projects to
cerebral cortex, nuc. accumbens, hippocampus (
central nucleus). Central nuc projects to brain
stem and hypothalamus produces automatic
responses.
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Molecular Aspects of BLA Neuroplasticity in
Conditioned Fear

• Critical roles of glutamate receptors
• Works the same as neuroplasticity underlying LTP
  in hippocampus
• NMDA is critical for acquisition of
  learning/inducing plasticity which results in
• Changes in the number AMPA which mediates
  long-term change in synaptic strength.

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Central Nucleus Outputs Functional Consequences.
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Protocol for inducing Contextual Conditioned Fear.
Contexual Conditioned Fear Phase 1 context
(distinct palce) with footshock. Phase 2 present
contextual cues in absence of footshock and
measure emotional expression (freezing). Acquisit
ion and Expression of this learned response is
dependent upon the amygdala and hippocampus.
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Hippocampus Encodes Context Information.
The hippocampus adds contextual regulation,
allowing you to distinguish the difference in
threat level posed by a snake in the woods vs. in
a zoo.
Hippocampus is important for encoding spatial
information (i.e how discreet environmental cues
determine a context).
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Connectivity of Prefrontal Cortex

• PFC has extensive connections with both the
  limbic structures and basal ganglia.
• Decisions are intimately connected to motivation
  and emotions.

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PFC and Cognitive control.
The medial prefrontal cortex regulates the degree
to which the amygdala expresses fear responses.
PFC which is involved in executive function
(e.g. decision making) provides cognitive control
over fear responding. -PFC also critical for the
relearning that occurs during extinction
training.
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Prefrontal Cortex and Emotionality
Phineas Gage received damage to the PFC resulting
in extensive changes in executive function
(irrationality) and emotionality (rage).
PFC is involved in both of the processes
(learning/memory emotion) attributed to limbic
system function so should it be considered part
of the system????
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Putting it togetherthe integrative systems
involves cortical, striatal limbic structures

• Cortical, striatal, and limbic circuitry, with
  localization of functions (a) Connection in
  human brain (b) Limbic cortical-ventral
  striatopallidal circuitry. (i) Processing of
  conditioned stimuli and delays by basolateral
  amygdala and of contextual information by
  hippocampus. (ii) Goal-directed actions involve
  interaction of PFC with nucleus accumbens but
  also dorsomedial striatum. (iii) 'Habits' depend
  on interactions between PFC and dorsolateral
  striatum. (iv) 'Executive control' depends on
  prefrontal cortex. (v) Emotional experience
  involves cingulate cortex and temporal lobe
  including amygdala, in functional imaging
  studies. (vi) Connections between dopaminergic
  neurons and striatum mediate limbic-motor
  interface.

Often we break different parts of the brain into
separate functional components (and this has
greatly facilitated our ability to study brain
function) but really the brain is a single system
that perceives circumstances (information),
stores retrieves information, makes decisions,
and initiates bodily responses.
Green/blue arrows, glutamatergic projections
orange arrows, dopaminergic projections pink
arrows, GABAergic projections Acb, n. accumbens
VS, ventral striatum DS, dorsal striatum AMG,
amygdala BLA, basolateral amg CeN, central
nucleus amg VTA, ventral tegmental area SNc,
substantia nigra pars compacta. GP, globus
pallidus (D, dorsal V, ventral) Hipp,
hippocampus mPFC, medial prefrontal ctx AC,
anterior cingulate ctx OFC, orbitofrontal ctx
Thal, thalamus.