Peripheral Nervous System Flashcards
Axospinous synapse has what type of synapse
Excitatory
Axodendritic, axosomatic and axoaxonic + or -
All are excitatory or inhibitory
Axoaxonic mechanism
Acts to increase or decrease NT release by post-synaptic terminal, which amplifies or suppresses the level or stimulation already occurring inside the post-synaptic term
Post-Synaptic density
Contains receptors and proteins that maintain or change synaptic structure
-can be seen on electron microscopy
Vesicles that are not docked at active zone are tethered by
Actin
How do pre docked vesicles release their NT
Calcium influx
How does calcium influx cause more vesicles to dock
Causes actin to de-polymerize, disassociate from vesicles, more vesicles dock, fuse, and release
Vesicles are recycled
At the synaptic cleft, what connects pre and post synaptic membranes
Cell adhesion molecules (transmembrane proteins)
These are critical to synapse formation and activity induced structural plasticity
differences in morphology of dendrites
Purkinje Stellate Spinal motor Pyramidal Unipolar
Sensory/Unipolar function and location
- Touch pain receptors in skin/viscera
- Taste receptors
- Typically located in ganglion
Motor neuron locations
- Anterior horn of spinal cord
- Brainstem (cranial nerve motor nuclei)
Local interneuron locations
Very short, unmyelinated axons in PNS and CNS
Neuroendocrine neuron location
Mostly in hypothalamus
Release peptide hormones into blood
Anterograde axonal transport
Kinesin to the terminals (+) end
Retrograde Axonal Transport
Dynein is retrograde toward soma (-) end
Slow anterograde transport
Transport of mitochondria and cytoskeletal proteins
Fast anterograde axonal transport
Enzymes that synthesize NT
Empty Vesicles
Vesicles with enzymes
Vesicles of neuropeptides
Neurodegenerative Diseases
Problems with axonal transport that have been implicated in age-related or pediatric neurodegenerative disease
Normal contents are not effectively transported
Viruses that spread via axonal transport
Varicella Zoster (chicken pox/shingles)
Rabies
Herpes simplex
Viral delivery of gene therapy
Genetically re-engineered viruses with normal human genes can be administered in periphery and retrogradedly transported to target neuron population
Proteins that cross link myelin to axon
MBP = myelin basic protein
PMP22 = peripheral myelin protein
Demyelinating disorders in PNS usually caused by
Degradation of MBP or PMP22
