Transcript Glutamate

Triune Brain: D.P. McLean
Organized in three strata of evolutionary progression. (ontology and phylogeny)
Reptilian brain: ( similar in a ll mam mals)
Innate behavioral knowledge: Basic
instinctual action tendencies and habits
related to primate survival issues. basic
motor plans, primitive behavioral responses
related to fear, anger and sexuality.
Limbic or visceral brain:
(small in r eptiles and
large in mamm als)
Affective Knowledge: Subjective feelings
and emotional responses to world events
interacting with innate motivational value
systems. Programs related to social
emotions, maternal acceptance, social
bonding, separation distress
Mammalian brain (neocortex) :
Human neocor.tex is vaster than all other ma mmals.
Declarative knowledge: propositional information about world events derived
especially from sight, sound and touch Influenced by emotions through appraisal
processes. The neocortex can rationally attempt to understand and influence
emotions
3/27/2006
The Triune Brain and Emotionality
Basal Ganglia - Seen as reptilian core of Triune
Brain.
Elaborates obligatory behavioral routineselimination, seeking, shelter, hunting, inactivity,
some social displays such as courtship,
aggression, submission.
Neural structures include basal ganglia,
substantia nigra, VTA and some amygdaloid
nuclei.
The Triune Brain and Emotionality
Limbic System- Surrounds core reptilian brain and
includes limbic cortex, stria terminalis, fornix,
olfactory bulbs, amygdala, hippocampus, septal
area, preoptic area, hypothalamus, central grey
area of midbrain.
Intimately associated with viscera. Provides
modulation over emotional functions of reptilian
brain and helps to generate pro-social emotions
such as play, maternal nurturance, separation
distress calls, grooming behaviors.
The Triune Brain and Emotionality
Neomammalian Brain- the 6 layered neocortex
which harvests information from the senses and
from memory, and processes such information
into neural representations of the world.
Primary role in emotions seems to be the
elaboration of appraisals which trigger
emotional responses.
BRAIN NEUROHORMONAL SYSTEMS
AND EMOTION
Amino Acid TransmittersGlutamate-Primordial excitatory NHT.
Learning, memory, consciousness.
Glycine-Simplest amino acid NHT.
Facilitates cognitive activity.
GABA-Primordial inhibitory NHT. Exerts
local homeostatic control within neuronal
circuits.
BRAIN NEUROHORMONAL SYSTEMS
AND EMOTION
Acetylcholine- Attention, Arousal and
Memory. It is involved in control of
hippocampal and cortical functions, REM
sleep, Thalamic information processing.
It is also involved in facilitating action
tendencies.
Dysfunction of system in Alzheimer’s
Dementia.
BRAIN NEUROHORMONAL SYSTEMS
Catecholamines - AND EMOTION
Dopamine- Projections from Substantia Nigra and
VTA to basal ganglia, limbic system (including
hippocampus, amygdala, nucleus accumbens,
hypothalamus) and prefrontal cortex. Functions to
control Psychomotor arousal.
Norepinephrine- Widespread Projections from
Locus Ceruleus to limbic system, cortex and spinal cord.
Functions to control sensory arousal.
Epinephrine- secreted as hormone from adrenal
medulla and from a few isolated cells in lower brainstem
with projections rostrally to hypothalamus. Functions to
control metabolic Arousal.
Catecholamine Systems and General Function
Panksepp, 1998
BRAIN NEUROHORMONAL SYSTEMS
AND EMOTION
ACH vs Norepinephrine- ACH is the
gatekeeper for incoming sensory
information to thalamus and cortex.
NE functions to change the signal to
noise ratio. Increased NE increase
processing of specific information
that ACH function has already
allowed into the thalamus and cortex.
BRAIN NEUROHORMONAL SYSTEMS
AND EMOTION
IndoIeamines Serotonin- Widespread Projections from
Raphe Nuclei to limbic system, basal ganglia,
neocortex. Increases in 5-HT have been associated
with sleep and reductions in motivated behaviors
such as feeding, sex, drinking, aggression and play
and so has been thought of as the rest and relaxation
NHT. This is not wholly accurate as stimulation of
different 5-HT receptor subtypes can increase
emotionality.
Neurotransmitter Systems
Panksepp, 1998
Panksepp, 1998
Panksepp, 1998
BRAIN NEUROHORMONAL SYSTEMS
AND EMOTION
Neuropeptides- Psychobehavioral specificity which is very
dose dependent.
B-Endorphin - Opioids function to reduce negative emotional
arousal and reduce the effect of painful stimuli, inherently
pleasurable
CRF-effect opposite to B-endorphin in that it is a crucial NHT in
the initiation of the general stress response, including behavioral
aspects
Vassopressin/Oxytocin-Oxytocin promotes the more female
behavior pattern of calm nurturance and inhibition of separation
distress, while vasopressin promotes the typically male sexual
persistence and aggressive assertiveness
CCK-Satiety and Panic
Neuropeptides and Emotional Responses
Panksepp, 1998
OTHER TRANSMITTER SUBSTANCES????
-Gaseous Transmitters
Nitric Oxide (NO)
Carbon Monoxide (MO)
-Neuro Growth Factors
Neurexins
Netrins
Neurotrophins
Basic
Emotional Systems
(Panksepp, 1998)
Behavior and Basic
Emotional Systems
(Panksepp, 1998)
Neural Basis of Seeking
(Panksepp, 1998)
Behavior and Basic
Emotional Systems
(Panksepp, 1998)
(Panksepp, 1998)
(Panksepp, 1998)
(Panksepp, 1998)
Behavior and Basic
Emotional Systems
(Panksepp, 1998)
(Panksepp, 1998)
NHTs and Fear
Norepinephrine
Serotonin
Glutamate
DBI (BZD Inverse Agonist)
CRF
Alpha MSH
ACTH
(Panksepp, 1998)
(Panksepp, 1998)
Neuropeptides and LUST
(Panksepp, 1998)
(Panksepp, 1998)
(Panksepp, 1998)
The Evolution of
Neural Systems
for Social Affect
(Panksepp, 1998)
Neuropeptides and Emotional Responses
Panksepp, 1998
Behavior and Basic
Emotional Systems
panic
• This is what happens with separation from
others like one self.
• *insight into depression and panic attacks
• Social bonds evolve as parents provided
young children with food, shelter, water and
warmth.
Bonding and distress
• Rene Spitz (1940’s)-evaluated babies in
orphanages.
– Human babies failed to thrive, and some even died,
when they failed to receive physical affection, even
though they received adequate physical care.
• All mammals inherit psychobehavioral systems
to mediate social bonding as well as various
other social emotions ranging from intense
attraction to separation induced despair.
Bonding and loss
• Social bonding probably goes hand in hand
with grief, loneliness and other feelings of
social loss.
• Since infants remain quite helpless for
amounts of time after birth, it seems
reasonable that they would evolve strong
systems for signaling separation distress and
soliciting and sustaining parental care.
Neurochemistry of panic
• Neuroanatomical areas involved in DV are
locations with CRF and B-endorphin systems.
– CRF increases distress vocalizations.
– Glutamate angonists (for NMDA and Kainate
receptor subtypes) initiate DVs--this response can be
evoked even is animal is with social companions.
– Neuropeptides that relieve DV’s include Bendorphins, prolactin and oxytocin.
• Panic and fear system are distinct in that benzodiazepines
reduce fear but not distress calls, while opiates are good at
reducing DV’s but not fear behaviors.
Panksepp, 1998
Chronic arousal of panic system
• Chronic arousal has long erm psychosocial
consequences.
• Persistent stress of social isolation
(accompanying over responsiveness of HPA
axis) may eventually contribute to the
despair and depression that follow social
loss and/or long term separation.
Harlow’s Monkeys
• Isolated Rhesus monkey babies will seek any
comfort they can, clinging to surrogate mothers
without food but covered in terry cloth as opposed to
wire mothers with ample food.
• Female monkeys (reared this way) were very poor
mothers, especially with first born. Their behaviors
were timid, emotionally over excitable.
• No type of conventional therapy (not drugs)
provided any long-lasting restoration of normal
social function.
• The most effective approach was exposure to much
younger mondeys as they provoked safe and playful
social interactions which drew the isolates out of
Panksepp, 1998
Panksepp, 1998
Epigenesis – a phenomenon is a mixture
of nature and nurture
Learning – process by which experience
changes the brain
Memories – actual changes in the brain
Neurodevelopment – activity dependent
realization of neuronal potential
Sensitive/Critical Periods - neurodevelopment is often
temporally constrained, as many neural connections pass through
(a) periods whereby their capacity of adjustment is substantially
greater than it will be in the adult brain .