CH 5 Synaptic transmission Electrical synpase bidirection rapid
CH 5. Synaptic transmission Electrical synpase (bidirection, rapid)
Electrical synpase; brainstem (breathing), hypothalamus-hormone release ATP, second messenger Cell signaling coupled metabolism in glial cells
Synaptic cleft Synaptic vesicles Neurotransmitter Ca 2+/ mast cell Exocytosis
Acetylcholine Co-transmitters Low frequency activity High frequency activity
Neurotransmitter 1. pre-synaptic vesicle – glutamate, glycine, asparate 2. Ca 2+ dependent, depolarization dependent release 3. Specific receptor in postsynaptic neuron
Small clear core vesicle-small molecule neurotransmitter 0. 5 -5 mm/day Neuropeptide- fast axonal transport (400 mm/day)
EPP; end plate potential Curare; inhibitor of Ach receptor MEPP; miniature end plate potential
One vesicle contained 100 m. M, 10000 molecule- MEPP
Local recycling 10 -20 sec 1 cycle/min 1 msec
Tetrodotoxin-Na channel inhibitor
Na+ channel blocker cannot completely block the Action potential The role of Ca 2+ in transmitter secretion
Lambert-Easton myasthenic syndrome (LEMS) Weakness and fatigability Presynaptic Ca 2+ channel loss Autoimmune disease- Ca 2+ channel Ab Congenital Myasthenic syndrome By Ach receptor or Acetylcholine diesterase
BAPTA; ca 2= chelator
Differential release of neurotransmitter
Primary target of Ca Synaptotagmin
Botulinum toxin, tetanus toxin protease (SNARE protein cleavage) A-latrotoxin; induce Ca 2+ independent exocytosis (spider venom) ca 2+ independent vesicle re Neurexin targeting (binding with synaptotagmin)
Patch clamp
End plate current End plate potential
• GABA; Cl- channel • EPSP; excitatory postsynaptic potential • IESP: inhibitory postsynaptic potential
KO model M 1 -forebrain, seizure-resistant, epilepsy model, IP-related M 2 -CNS, heart and Smooth muscle, spinal cord 심장박동, learning and Memory (auto. R), 통증 , Gi M 3 -식욕 M 4 -auto. R, GABA regulation M 5 -blood vessel contrcation N 1 N 2
Alpha: 1 -10 Beta: 2 -4
- Slides: 50
