Sensory

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Sensory Motor SystemsMultiple structures at
different levels of the Central Nervous System
? Visceral Emotion System(s)?
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Areas of Differential Activity in Subjects w/
Major Depression
from Wayne Drevets
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Deep Brain Stimulation for Depression
Mayberg, et al. Neuron. 2005 45651-660.
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Emotionand Visceral Activation
William James (in What is Emotion?) We feel
sorry because we cry, angry because we strike,
afraid because we tremble and not that we cry,
strike, or tremble because we are sorry, angry,
or fearful as the case may be.
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Levels of the CNS for Visceral/Emotional Control
Basal Ganglia
Thalamus
Med Prefrontal Ctx
Amygdala
Hypothalamus
Midbrain (PAG)
Hippocampus
Brainstem (Medulla)
Spinal Cord
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Control of Visceral Functions at different levels
of Brain Sp. Cord

• Spinal Cord - Autonomic (sympathetic) output
  input
• Medulla - Para-sympathetic output input Reflex
  control of specific visceral functions
• Midbrain (Periaqueductal Gray) - Coordination of
  multiple functions in response to stress (esp.
  pain)
• Hypothalamus - Coordination for homeostasis
• Amygdala - Modulation in relation to fear
  threat (memory also other limbic structures)
• Ventro-medial Prefrontal Cortex - Modulation in
  relation to cortical/cognitive functions
  (together w/ related parts of Thalamus Basal
  Ganglia)

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Spinal Nerve Peripheral Nerve
Somatic and Visceral Components
Sensation from Skin, etc. Motor to Skeletal Muscle
Control of Visceral Organs, etc. (also feedback
from viscera)
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Sympathetic Reflexes Afferent Efferent Limbs
Afferent fibers w/ Sympathetic nerves carry pain
fibers from viscera - We refer this to skin
dermatome of same spinal segment
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Sympathetic
Parasympatheic
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VagusEfferent Afferent
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Reflex control of Visceral Functions at level of
Medulla

• Baroreceptor Reflex - Blood Pressure
• Respiration - Maintain inspiration/expiration
  modify in response to changing situations.
• Gut motility and enzyme secretion.
• Micturation
• Also somatic brainstem reflexes such as Startle
  Reflex

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Baroreceptor Reflex
Vagus
carotid sinus baroreceptors
rostral ventrolateral medulla
aortic arch baroreceptors
nucleus of the solitary tract
nucleus ambiguus
Medulla
caudal ventrolateral medulla
Vagus, Para-Sympathetic
ACh
tonic
ACh
intermedio-lateral column
Sympathetic
NAdr
ACh
Spinal Cord
Peripheral Arterioles
ACh
NAdr
With thanks to Cindy Montana
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Startle Reaction
Modified by descending influences, e.g. from
Amygdala or PAG in relation to fear stress.
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Periaqueductal Gray
Coordinate Visceral Behavioral Responses
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Midbrain, Inferior and Superior Colliculus
Cerebral Aqueduct
Sup. Colliculus
Inf. Colliculus
PAG
PAG
Dorsal Raphe
Cerebral Peduncle
Sub Nigra
Sub Nigra
Cerebral Peduncle
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Columns of PAG Coordinate Response to Stress
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Hypothalamus
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Hypothalamus Coordination of Autonomic
Endocrine Systems
To Brainstem Autonomic Nuclei
PVN
LHA
SON
To Ant. Post Pituitary
Op Tract
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Functions of the Hypothalamus Coordinate
Visceral Control for Homeostasis

• Thermoregulation
• Circadian Rhythm, Light/Dark Cycle
• Fluid Balance, Blood Volume Pressure
• Ionic Balance, Osmolality
• Food Intake and Energy Metabolism, Body Weight
  
• Sleep Initiation and Stability
• Stress Response
• Reproduction, etc.

Likely involved in depression
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CRH ELICITS RESPONSE TO STRESS But also involved
in Depression
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Amygdala
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Amygdala Connections
Amygdala Connections
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Role of Amygdala in Fear ConditioningDescending
projections modulate brainstem reflexes
Amygdaloid lesions abolish fear-related
potentiation of startle reaction
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Amygdaloid lesions in humans block fear and
recognition of fear
SM
SM
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Amygdala Preferred Personal Space
Near vs Far
Normal subjects
SM had no measurable minimum interpersonal space
Kennedy et al. 2009 Nature Neurosci. 121226-7.
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Orbital and Medial Prefrontal Cortex (OMPFC)
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AChE and Nissl staining of areas in the caudal
Orbital Cortex in Monkeys
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Medial Orbital Prefrontal Networks
Monkey
Human
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FoodReward
Visceral ControlEmotion
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Rolls, Critchley, Browning, Hernadi, and Lenard,
Responses to the sensory properties of fat of
neurons in the primate orbitofrontal cortex.The
Journal of Neuroscience, 1999, 191532-1540
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FoodReward
Visceral ControlEmotion
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Activation of Human Medial Prefrontal Cortex
during Autonomic Responses to Hypoglycemia Teves,
Videen, Cryer, Powers (2004) PNAS, in press
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Critchley, Elliott, Mathias, Dolan, 2000
Activity covarying w/ SCR in a gambling task
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Effect of VM Frontal Ctx Lesions
Skin Conductance Response to gambling task
Bechara, Damasio, Damasio, Cerebral Cortex 2000
10295-307
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Orbital Medial PFC Networks Connections with
other cortical areas (in Temporal, Insular, and
Cingulate Cortex)
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Raichle and colleagues
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Thalamus Basal Ganglia
Striatum
Striatum
Globus Pallidus
Thalamus
Thalamus
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Cortex
Striatum (Caudate, Putamen, Accumbens)
Thalamus
Globus Pallidus
Subcortical Inputs
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Orbital Medial PFC Network connections with MD
Thalamus Striatum
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Cortico-striatal Zones in Striatum
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Schultz W, Apicella P, Scarnati E, Ljungberg
T.Neuronal Activity in Monkey Ventral Striatum
Related to the Expectation of RewardJ. Neurosci
1992, 124595-4610.
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Medial Prefrontal Cortex
MD Thalamus
Amygdala
Ventral Pallidum
Ventromedial Striatum (Nucleus Accumbens etc
Hypothalamus PAG
Lower Autonomic Nuclei
Endocrine System
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Areas of Differential Activity in Subjects w/
Major Depression
from Wayne Drevets
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Mayberg, Liotti, Brannan, McGinnis, Mahurin,
Jerabek, Silva, Tekell, Martin, Lancaster, Fox.
Am J. Psychiatry 156675-682.
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Subgenual Part of Area 24
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Pezawas et al (2005) 5-HTTLPR polymorphismNatur
e Neurosci.8828-834.
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Glia Density in Subgenual Area 24


Öngür, Drevets, Price PNAS, 1998, 9513290-13295.
Similar results were obtained in the orbital and
the anterior cingulate cortex by Rajkowska et al,
1999, and Cotter et al, 2001.
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Glial Changes in Amygdalain Mood Disorders


p lt 0.05
Bowley, Drevets, Ongur, Price (2002) Biol. Psych
52 404-412.
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Oligodendrocyte Astrocyte Density in Amygdala
vs Mood Disorders

p lt 0.05
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Glia/Neuron Ration in Amygdala
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Amygdala Volume in Bipolar Disorder
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