new hope for hurt neurons is there recovery after damage to the spinal cord or brain? can stem cells...

New Hope for Hurt Neurons

• Is there recovery after damage to the spinal cord or brain?

• Can stem cells be used to reconstruct broken pathways?

• A few years ago, the stuff of myths.

• Perhaps a reality

Christopher Reeve as Superman

Christopher Reeve Paralysis Foundation

www.paralysis.org

Reeve’s Goal

To Stand and Raise a Glass on 50th Birthday.

9/25/2002

Traditional Divisions

KW 2-13

Functional Divisions

KW 2-13

CNS and PNS

KW 1-2

Brain in Skull

KW 2-1

CNS and PNS (sketch)

SkullBrain

Spinal cord

Nerves (PNS)

Vertebrae

Neurons and Glial Cells

KW 2-12

Neuron

KW 3-3

Types of Neurons

KW 3-7

Neuron (detail)

KW 3-5

Neuron (info flow)

KW 3-6

Types of Glial Cells

KW 3-1

Glial Cell Functions

• Supportive glial = glue

• Nutrition

• Waste disposal “vacuum cleaners”

• Insulate neurons

Neurons vs Glial Cells

• Neurons• Transmit message.• Mature cells don’t

replicate.• Dead cells are not

replaced.

• Glial cells• Supportive role.• Mature cells do

replicate.• Dead cells are

replaced.

CNS and PNS Myelin

Astrocyte

KW 3-9

Myelin Wrap

CNS

PNS

Myelin Sheath in PNS

Axon

Myelin Sheath

Schwann Cells in PNS

Schwann cell beakdown

KW 3-11

Schwann Cell Recovery

KW 3-11

Combo Schwann

KW 3-11

Can axons regrow in CNS?

• Yes, but their path is blocked by CNS Glial Cells.

• CNS Glial cells (Oligodendrocytes) form scar tissue.

• Pathway is blocked by scar tissue.

scar

CNS Solutions

• Block scar tissue from forming.

• Schwann cell bridges (Lars Olson).

• Spinal motor pathways cut in rats.

• Loss control of hind limbs.

Other CNS Solutions

• Nerve growth factors.

• Stem cell implants.

• Quick response to spinal cord injury.

• “Golden Hour” = first hour after injury.

• Prevent further damage.

Rapid Response to Injury

• Steroids to reduce swelling.

• Provide support.

• Cord usually not severed.

• Relieve pressure.

• Stabilize vertebrae.

Recovery from injury

• Drugs to help remaining neurons function better.

• Retrain body to use back-up systems.

• Functional Electrical Stimulation (FES): a computer assisted movement system

Functional Electrical Stimulation

Hand Grasp in Operation

Spinal Cord Outcomes

• 12,000 new cases a year

• Most young men.• 90% survive accident.• Lifetime disability• Greater hope for

recovery.