repair and regeneration of the nervous system
DESCRIPTION
Repair and Regeneration of the Nervous System. What’s Capable of Being Repaired or Regenerated?. Whole Neurons Axons Synaptic clefts Neuromuscular junction Receptors. Whole Neurons. Death is programmed ( apotosis ) or immediated ( necrosis ). If you had too much MSG…. - PowerPoint PPT PresentationTRANSCRIPT
Repair and Regeneration of the Nervous System
What’s Capable of Being Repaired or Regenerated?
• Whole Neurons• Axons• Synaptic clefts
• Neuromuscular junction
• Receptors
Whole NeuronsDeath is programmed (apotosis) or immediated (necrosis)
If you had too much MSG…..
Axons (Peripheral Nerves)
Axons Derive From Growth Cones
How Do Axons Know Where To Go?
• Blueprint Hypothesis– Axons migrate towards a tissue in a pre-
determined manner
• Chemical Affinity Hypotheis– Axons migrate towards a tissue based on
feedback from “chemoattractants” and “chemorepellants”
– Ephrin (retractant), Semaphorins (both)
Signaling Disruption of Axon Growth
Synaptic Clefts (Neuromuscular Junction)
Principles of Neural Science (Kandel); Chapter 55
Formation of a Neuromuscular Junction
• Growth cone approaches a new formed myotube
• Forms an unspecialized contact• Multiple axons converge on a single site• All but one are eliminated
– Survival of the fittest
Principles of Neural Science (Kandel); Chapter 55
What Happens With a Loss of Nerve and Tissue?
Principles of Neural Science (Kandel); Chapter 55
Differentiation of Synaptic vs. Non-synaptic Regions
Principles of Neural Science (Kandel); Chapter 55
Receptor Aggregation
Neuregulin: enables the formation of AcH receptors at the neuromuscular junction
Cytoplasmic Proteins
• link receptors together
Macromolecular Complexes
Principles of Neural Science (Kandel); Chapter 55
• link pre- and post-synaptic membranes together
Neurotrophic Factors
• Guide neuron survival and outgrowth on neurons
• BDNF, NT-3, NT-4 and 5• Hot factor to study beyond
neuron repair and regeneration (drug addiction)
Case Study: Stroke, Chemical Warfare, and Neuregulin
Spinal Cord Regeneration with Channel Rhodopsin
• Achieved through optogenetics
http://www.scientificamerican.com/video.cfm?id=method-of-the-year-2010-12-22