Transcript Environmental Effects on the Brain

Module 12: Brain Plasticity
The brain’s ability to modify itself after damage
2 Types of Plasticity
1. Structural Plasticity – Actual changing of
the neuron or actually growing new
neurons.
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•
Neurogenesis only occurs in the hippocampus
Stem Cells could be used to develop into a
neural cell that needs to be replaced.
2. Functional Plasticity – When an area of
the brain takes up a new function to
replace a damaged area of the brain.
Examples of Plasticity
• If a body part is amputated, the surrounding neurons in
the somatosensory cortex rewire themselves to other
areas in the body.
• Example: The hand is between the face and are regions
on the sensory cortex thus when stroking the face of
someone whose hand was amputated, the person felt the
sensation not only on their face but also on their
nonexistent “phantom” fingers.
• A 5-year old boy who had severe seizures in his left
hemisphere required the removal of the entire
hemisphere. What was the result? While he is paralyzed
on his right side he grew up to have above average
intelligence, completed college and grad school and is
now a business executive.
More Examples of Plasticity
• A laser beam damages a spot in a cat’s eye, the
brain area that received input from that spot will
soon begin responding to stimulation from nearby
areas in the cat’s eye.
• Newborn ferrets had the optic nerve of their brains
rewired to take visual information into their
auditory cortex. Result? It could see light in its
auditory cortex.
• If a blind person uses one finger to read Braille,
the area of the brain dedicated to that finger
expands.
• The sense of touch invades the part of the brain
normally used for sight in blind people.
More on Phantom Limbs
• Mirror Therapy to help with Phantom limb pain. See
video HERE for explanation (4 min).
•Create a Fake Phantom Limb Demo
Brain Plasticity
Can the brain rewire itself if you
lose your vision?
7:03 minute clip
Click below to view video
What happens when you’re born
without a portion of your brain?
See video from class on hydrocephalic
Can a person’s environment
affect their brain development?
YES!
Click on
video box to see
how
London Cab
Drivers
rewire their
brain
An enriched environment = more
neural connections in the brain.
•Exercise will cause more blood
vessels to grow
•Learning Activity will cause more
dendrites and axon terminals and
thus more neural connections.