1. Nervous system Ⅱ Wei yuanyuan

2. Neurotransmitter  Definition : a small molecules released by presynaptic neuron into synaptic cleft that cause a change in post synaptic potential

3. Neurotransmitter  Synthesized and released from neurons  Found at the presynaptic terminal  Same effect on target cell when applied in vitro  Blocked by same drugs that block synaptic transmission in vitro  Removed in a specific way  Break down  reuptake

4. Neurotransmitter  ACh ChE Choline and acetic acid reuptake NE Peptide NT. zymolysis

5. Classification of neurotransmitter  Neurotransmitter in CNS  Neurotransmitter in PNS

6. Neurotransmitter in PNS  Acetylcholine (ACh)  Noradrenaline (NA) or nor-epinephrine(NE)  Peptide

7. Acetylcholine (ACh)

8.  Cholinergic fiber  Sympathetic and parasympathetic pre-ganglionic fiber （ N 1 R ）  Parasympathetic postganglionic fiber  Sympathetic cholinergic fibers to the sweat glands,muscular blood vessels  Sympathetic vasodilator nerve fibers of the muscles (defensive response)  Motor nerve fibers （ N 2 R)

9. Acetylcholine (ACh)  The life cycle of ACh

10. Cholinergic Agonists  Direct agonists  Muscarine –MR(M1~M5)  Nicotine—NR(N1,N2)  Indirect agonists  ACh E Inhibitors: organophosphorus pesticide

11. Cholinergic Receptor  Muscarinic receptor (MR)  Muscarine –like action  G-protein-coupled receptor  Subtypes:M1~5  M1: postganglionic nerve and stomach  M2:heart  M3:vascular smooth muscle,  endocrine and exocine gland,  e.g. salivary glands and stomach.  M4 and 5:CNS

12. Muscarinic – like action Muscarinic effect  Inhibition of heart  contract the SM in bronchus, GIT, urinary bladder ， iris circular muscle  Increase the secretion of digestive gland salivary gland and sweat gland  Blood smooth muscle in skeletal muscle relax  Antagonists:  Atropine mydriatic

13. If atropine is applied, what will happen ?

14. 2. Nicotine receptor (NR) ligand-gated ion channel

15. Tubocurare is alkaloid obtained from the bark of the South American plant Chondrodendron tomentosum, a climbing vinealkaloidChondrodendron tomentosum Curare had been used as a source of arrow poison by South American natives to hunt animalsarrow poison skeletal muscle relaxant

16. Nicotinic – like action  Skeletal muscle contraction (low dosage ACh)  Blocking the signal transmission in autonomic nervous ganglion (high dosage ACh)

17. Neurotransmitter receptors Receptors, ligands (agonist and antagonist)

18. Norepinephrine Epinephrine

19. Norepinephrine (NE)  Adrenergic fibers  Most sympathetic post-ganglionic fibers

20. Adrenergic receptor  1. αR  Antagonist:Phentolamine:  Subtype:  α 1 R :smooth muscle  α 2 R: presynaptic membrane

21. α 1 receptor:smooth muscle contraction. Antagonist:prazosin 1.vasoconstriction in skin gastrointestinal system,renal artery and brain. 2.Other areas of smooth muscle contraction are : ureter and urethral sphicter arrector pili muscles uterus (when pregnant) brochioles (although minor due to the relaxing effect of β 2 receptor on bronchioles) blood vessels of ciliary body (stimulation causes mydriasis)mydriasis

22. Specific actions of the α 2 receptor : Antagonist: yohimbine agonist ： Clonidine Inhibition ofinsulin release. Induction of glucagon release from the pancreas. Contraction of sphincters of the gastrointestinal tract presynaptic inhibition of noradrenalin release in CNS

23. Propranolol:

24.  β 1 R: heart  β 2 R: blood smooth muscle in liver and skeletal muscle  β 3 R: adipose tissue  NE α 1 R: contraction of smooth muscle  β 1 R: contraction of cardiac muscle  β 2 R: relaxation of smooth muscle

25. The sympathetic nervous system is responsible for the fight-or-flight response, which includes widening the pupils of the eye, mobilizing energy, and diverting blood flow from non-essential organs to skeletal muscle.fight-or-flight responseskeletal muscle

26. Neurotansmitters in CNS

30. Nervous reflex

31.  Types  Conditioned reflex (Pavlov, Russia)  Unconditioned reflex （ primitive reflex ）

33. Tendon reflex

34. Cross flexor reflex

37. Recurrent connection: basic structure of negtive feedback, positive feedback after discharge

38. Summary  Neurotransmitter  Conditioned reflex  Describe the cholinergic fiber and receptor of the body