Transcript lectSides08.ppt

Transmitter Release
January 19th, 2005
PNSIV F-14.1
PNSIV F-14.2
PNSIV F-14.4
PNSIV F-14.3
Spontaneous release(0.5mv): How many molecules?
Is the normal synaptic potential quantized?
Decreasing Ca2+ affects probability of release
PNSIV F-14.6
Katz and Miledi Hypothesis
1. Transmitter quanta are stored in vesicles each containing
about 5,000 molecules (ACh.)
2. Vesicles are released at nerve terminal by exocytosis.
3. Depolarization, increases release by increasing influx of
Ca2+ which in turn increases the probability of release by
combining with release sites, allowing vesicles to fuse.
PNSIV F-63.3
PNSIV F-14.8
PNSIV F-14.15
PNSIV F-14.14
PNSIV F-14.16
PNSIV F-14.17
PNSIV F-14.18