1.4.1 Neurodevelopment II Flashcards
How do trophic factors and neurodegeneration play a role in Huntington’s?
Bilateral Horner’s Syndrome is a feature of CIPA. What is it?
Dry skin, constricted pupils, and drooping of the eyelid
Infection due to overzealous scratching or rubbing, especially during sleep.
What is the receptor for NT-3?
TrkC
What are trophic factors?
- Proteins involved in the regulation of survival of neurons during development
- Endogenous, soluble proteins regulating the survival, growth, morphological plasticity, or synthesis of proteins for differentiated functions of neurons
What neuronal populations are supported by NGF?
- Sympathetic
- Nociceptive Sensory
- Cholinergic basal forebrain
Addition of exogenous trophins can lead to what in neuronal development?
-results in additional retention of neurons despite same amount of target tissue
Describe the developmental actions of neurotrophins.
- Prior to innervation, there is a surplus of neurons having the potential to contact a target
- Properties of the target determine the final number of neurons innervating the target
- The rest of the neurons undergo naturally occuring cell death (NOCD)
How do trophic factors and neurodegeneration play a role in peripheral neuropathy?
Antibodies against NGF have been used to treat?
Chronic pain associated with osteoarthritis
Depriving neuronal cells of their trophic factors will result in what?
-Deprivation of trophic factors will result in structural changes similar to axonal injury
-Axotomy – deprivation of trophic factors (cut axon) → axon undergoes Wallerian degeneration → swelling of cell body → chromatolysis (dispersal of Nissl substance)
What is the receptor for NGF?
TrkA
What is the underlying cause of CIPA?
- Caused by loss of function genetic mutation preventing the formation and development of sympathetic nerve cells responsible for transmitting signals of pain, heat, and cold to the brain
- Mutation is specifically in the gene encoding the TrkA (NTRK1 gene) receptor
What neuronal populations are supported by BDNF NT-4/5?
- Motoneurons (alpha)
- Vestibular & Peripheral Sensory
- Cranial Ganglion
- Cortical neurons
Addition of antibodies to trophic factors can lead to what in developing neuronal populations?
results in increased NOCD despite same amount of target tissue
Clinical delivery of trophic factors depends on?
Delivery to where they exert their force, not where they are produced
How do trophic factors and neurodegeneration play a role in Alzheimer’s?
What are the features of CIPA?
-Genetic disorder preventing pain sensation, heat, cold, or any nerve-related sensations and includes inability to sweat
What is the receptor for BDNF/NT-4/5?
TrkB
The family of neurotrophins (NGF, BDNF, etc.) have one receptor they can bind in common. What is this receptor?
p75
How do trophic factors and neurodegeneration play a role in Parkinson’s?
What are some of the different types of trophic interactions?
target to neuron
neuron to neuron (CNS)
glia to neuron
anterograde (transmission) or retrograde (apoptosis)
paracrine or autocrine
Neurotrophic actions are mediated by?
Transport of receptor-ligand complexes to the soma
This process will be altered anytime that retrograde transport is affected
How do trophic factors and neurodegeneration play a role in ALS?
What is the neurotrophic hypothesis?
production of limited amounts of neurotrophin by target areas retrogradely supports a select number of neurons, thus matching the size of neuron populations to the size of the target innervation fields
What neuronal populations are supported by NT-3?
- Proprioceptive sensory
- Motorneurons (gamma)
- Cranial Ganglion
- Corticospinal Neurons
What is CIPA?
Congenital Insensitivity to Pain and Anhidrosis
