1. Ch. 5 Synaptic transmission
Electrical synapse
Chemical synapse 雙向 快速

2. Electrical synapse: to synchronize electrical activity among populations of neurons (hypothalamus)
crayfish
小龍蝦
ATP, c-AMP

3. Chemical synapse AP
voltage-dependent
Ca2+ channels

4. Quantal transmission at neuromuscular synapses
End plate potential (EPP)
spontaneous changes occur in muscle cell mambrane miniature end plate potentials (MEPPs): occur even in the absence of stimulation, block by curare (ACh receptor blocker)
EPP = summation of MEPPs
Low Ca2+
EPP fluctuations

5. 假說：these “quantal” fluctuations suggest that EPPs are made up of individual units, each equivalent to a MEPP
驗證：independent occurrence of unitary events (Poisson statistics): predict the distribution of EPP amplitudes
結論：presynaptic AP causes a postsynaptic EPP because it synchronizes the release of many transmitter quanta

6. Release of transmitters from synaptic vesicles: one synaptic vesicle is one MEPP
Fusion of synaptic vesicles with the presynaptic membrane
4-AP 會影響 AP 的 duration-> Ca2+

7. Dock: two membranes become tightly associated with each other
prime: active fusion of the membranes

8. The role of Ca2+ in transmitter secretion
有五種實驗證明 nerve terminal 有 voltage dependent Ca2+ channels 存在：(1) Na+ channels blocker (2) voltage clamp experiment 如圖所示 (3) Ca2+ imaging 如下圖 (4) 直接打入 Ca2+ (5) Ca2+ chelators
The purpose of AP is to activate Ca2+ channels
-latrotoxin triggers Ca2+ independent exocytosis
Ca2+ channel blocker 鎘
Block Na+ & K+ channels

9. Fura-2
在 presynaptic neuron 打入 Ca2+
Ca2+ chelators

10. Synaptotagmin:
Ca2+ sensor, bind to neurexins
NSF & SNAP:
common proteins in fusion, 與
SNARE 結合 (SNAP receptors 包括 synaptobrevin, syntaxin& SNAP-25)

11. Toxins that affect transmitter release
Clostridial toxins (梭狀芽孢桿菌毒素), botulism (肉類桿菌中毒), tetanus (破傷風)
botulinum toxin & tetanus toxin: cleave synaptobrevin, syntaxin & SNAP-25
female black widow spider: -latrotoxin triggers Ca2+-independent exocytosis, bind to neurexins

12. Ch. 6 Neurotransmitters
The utility cycle of all neurotransmitters: (1) synthesized & packaged (2) release & binding (3) removed or degraded
classified into tow broad categories: (1) small-molecule NMs (2) neuropeptide

13. What defines a neurotransmitter?
1926, Otto Loewi
Vagus nerve
Heart rate
Heart rate
“vagus substance” ACh

14. Criteria that define a substance as
a neurotransmitter: Box A 斜體字

15. The comparisons of neurotransmitters to hormones
Action at a distance
vasopressin, oxytocin, can be as a hormone and as a NM

16. Two major categories of neuro-transmitters
(1)small-molecule
neurotransmitters: ATP, AMP
(2) peptide
neurotransmitters

18. 請任舉兩個實驗證明 nevre terminal 具有 voltage-
dependent Ca2+ channels。
請說明 Otto Loewi 證明神經傳導物質存在的實驗。