Neurotransmitters and its mechanism of action

1. Neurotransmitters and its mechanism of action Presented by R.Parthasarathy

2. INTRODUCTION : What is neurotransmitter Criteria General characteristics features Classification biochemical physiological Mechanism of action of individual chemical

3. ANATOMY OF NERVE: Postsynaptic: Muscle  Contraction Neuron  Action potential Glands  Secretion

4. DEFINITION: Neurotransmitters are the chemical substances which are responsible for transmission of an impulse through a synapse. Schematic diagram of synapse

5. CRETIA: 50 substance are there Synthesized by pre-synaptic neurons with the help of synthesizing enzyme and stored in vesicles at axon terminal. Stimulation of nerve cause release of transmitters. Travels between pre to post- synpatic membrane. Associated with an enzyme system(inactivation). Mimic the effects of nerve stimulation outside. Drugs which modifies nerve stimulation also modifies transmitter action the similar way.

6. Neuromediators or neurohormones : Neuromodulators : Eg : VIP,somatostatin,ckk,substance P etc Neuromodulators :

7. ACTION OF NEUROTRANSMITTERS general characteristics Neurotransmitter travels pre  post synaptic Receptors associated with Ion channels and enzyme (second messenger) Acts in milliseconds Activate both pre and post synaptic receptors. More transmitter interact both pre and post synaptically (Sp Rec & sp effects)

8. CLASSIFICATION: BIOCHEMICALLY

9. PYSIOLOGICALLY EXCITATORY Eg:Acetylcholine Aspartate Dopamine Histamine Norepinephrine Epinephrine Glutamate Serotonin INHIBITORY GABA Glycine

10. Excitatory neurotransmitters:

11. Inhibitory neurotransmitters:

12. Acetycholine : SYNTHESIS: Vasodilation , cardiac inhibition, GI peristalsis; control of thought, mood, sleep, muscles, bladder, sweat glands

13. Catecholamines : Dopamine: Control of movements(parkinsonism) Induction of vomiting Inhibition of prolactin secretion Stimulation of GnRH Schizophrenia SYNTESIS

14. Serotonin: SYNTHESIS: FUNCTIONS : Regulation Carbohydrate intake & Hypthalamic releasing hormone Pain inhibition Hallucinations and 5HT Depression of mood

15. Histamine: SYNTHESIS:

16. Amino acid: SYNTHESIS:

17. OVERVIEW .

18. Neuropeptide transmitters:

19. General mechanism of action

20. Acetylcholine esterase

21. Thank you