Transcript Barry Jacobs presentation

THE ORGAN
of
EDUCATION
What % Of Our Brain Do We Typically Use?
(let’s have a show of hands)
10%
30%
50%
80%
!00%
How many of you
believe that you mind is
COMPLETELY
contained within or
COMPLETELY
controlled by the 3.5 lb.
of gray mush that lies
within your skull?
MIND
• Is the mind a manifestation of brain function? If not,
what is it?
• If it is, then it is the manifestation of physico-chemical
components. How is this different than a rock, a
computer? Do computers think? Do they have free
will, consciousness, and emotion?
• Could we build a machine with the same physicochemical components of our brain that would have a
mind? Why not?
THIS PROFESSOR’S GOT A BRAIN!!!
PAUSE
for
DISCUSSION
Learning (or behavioral plasticity) – the acquisition of a reversible
change in behavior resulting from experience (consciously or unconsciously)
Memory – the process by which we retain knowledge over time.
DEVELOPMENT
Development of Dendritic Growth in Human Visual Cortex
Surface of Brain
NEWBORN
3 MONTHS
2 YEARS
Genes may instruct overall structure, such as what layer of cortex (I – VI) a cell should migrate
to, but not the billions of synaptic connections (determined by use and experience)
EAT, SLEEP, INFREQUENTLY AWAKE FOR LONG PERIODS
CRITICAL PERIODS
• There are times during development when
conditions must be right or it may be difficult or
impossible to correct them later.
• A young child who is abused or neglected may
have great difficulty in successfully navigating
adult social life.
• If not corrected early on in life an infant with
cataracts or “lazy eye” may grow up to have
imperfect vision.
USE IT OR LOSE IT!
Two of the major processes
in the developing brain
1. Pruning of axons and dendrites
2. Cell death (APOPTOSIS programmed cell
death – can be caused by gene activation)
QUESTIONS?
Plasticity
An important catchall that covers all of
experience-induced changes in brain.
It is critical to appreciate the fact that all areas
of the brain can show plasticity, and that all
that you experience alters your brain!
Granule cell layer of the
Dentate Gyrus
OUTPUTS
INPUTS
THIS PROCESS TAKES WEEKS – THERAPEUTIC LAG?
Gage Lab
Bromodeoxyuridine is used to replace thymidine
This process declines dramatically in the aged
Effects of Insomnia
Insomnia (lack of sleep or frequent sleep
interruption) can produce or exacerbate
physical and psychological ailments (it exerts
negative effects upon the immune system).
I strongly believe that there is a bidirectional
relationship between CLINICAL DEPRESSION
and insomnia.
Hippocampal
Regions
Control
Sleep Deprivation (SD)
SD+Recovery
Posterior
1719.6±152.4
948.8±76.8⁎⁎ (−44.8%)
914.4±198.0⁎ (−46.8%)
SLEEP IS IMPORTANT FOR
LEARNING AND MEMORY
During sleep, the brain appears to reactivate or
“replay” the pattern of neuronal activity of the
initial exposure to the material to be learned.
A SMALL SAMPLE OF FACTORS
AFFECTING ADULT BRAIN NEUROGENESIS
INCREASE
DECREASE
Exercise
Exploration
Learning
Estrogen
Brain Damage
Adrenal hormones
Predator Odors
Stressors
Sleep Loss
Auditory cortex of accomplished
musicians is 130% larger than that
of control subjects
Representation of fingers 2-5 of the
left hand in somatosensory cortex
of violinists is larger than that of
their right hand
EPIGENETICS
Heritable changes in gene expression caused by mechanisms
other than changes in the underlying DNA sequence. They may
remain through cell divisions for the remainder of the cell's life
and may also last for generations.
As an example, abuse of an infant may change her gene
expression and this may be manifested in adulthood (e.g.
psychopathic personality). AND, this may be transmitted across
the next generation to her own children.
Think of the implications of this for education.
PAUSE
FOR
DISCUSSION
LEARNING
&
MEMEORY
DENDRITE
1.
AXON
1.
2.
NEUROTRANSMITTER
SYNAPSE
e.g. cyclic AMP, formed when a
G-protein is activated and
converts ATP to c-AMP, goes on
to activate specific proteins
(esp. kinases)
NUCLEUS
Memory is mental time travel. It allows
us to go back in time to relive the
moment. If memories are not strung
together in a meaningful and coherent
fashion, it’s like looking at someone else’s
family photos.
Long-Term Storage of Information
• Complex experience activates numerous areas
of neocortex
• These areas activate hippocampus
• In turn, hippocampus “binds” these cortical
areas
• These cortical areas now act autonomously
and in concert to generate long term memory
Auto Accident
?
A MAJOR PUZZLE!
MOTOR
(M)
*
AUD
(A)
SOMAT
(S)
A synapse that increases its effectiveness because of simultaneous activity in
the pre – and post-synaptic neurons is called a Hebbian synapse (*).
S can activate M but A alone can’t. But if A & S fire together, then the
connection between M & A is strengthened.
O = nitric oxide
NO
NO
1
MONOAMINE TERMINAL
2
3
Release of glutamate stimulates NMDA receptors, and the resulting influx of CA2+ activates nNOS.
NO synthesized by the enzyme spreads over in a sphere and reaches monoamine terminals. NO
inhibits the function of transporters (T), which increases monoamine concentrations.
Episodic
Semantic
Further Division of Declarative Memory
• Spatial -- location
• Factual or Semantic --words and their meaning,
people, faces, objects, concepts – all in discrete
categories. FACTS
• Episodic -- “snapshots” of life events. Typically
of important events.
BELL &
FOOD
BAR &
PRESS