1. Madan Baral
B. Pharmacy 3rd
Semester
Roll-8

2. • Identify neurotransmitters
• Understand the physiology of neurotransmission
• Classify neurotransmitters
• Biosynthesis
• Major neurotransmitter systems : simple anatomy
and functions

4. • Neurotransmitters are endogenous
chemicals which transmit signals from a
neuron to a target cell across a synapse.

5. • Ramón y Cajal (1852–1934) discovered a 20 to 40 nm
gap between neurons, known today as the synaptic cleft.
• In 1921, German pharmacologist Otto Loewi (1873–
1961) confirmed that neurons can communicate by
releasing chemicals.
• Otto Loewi is accredited with discovering acetylcholine
(Ach)-the first known neurotransmitter
• However, some neurons communicate via electrical
synapses

6. How do we
identify if a
compound is a
neurotransmitter?

7. Chemical can be classified as a neurotransmitter if it meets the
following conditions:
1.There are precursors or synthesis enzymes located in the
presynaptic side of the synapse
2.It is available in sufficient quantity in the presynaptic neuron to
affect the postsynaptic neuron.
3.There are postsynaptic receptors and the chemical is able to bind to
them.
4.A biochemical mechanism for inactivation is present.

11. 1. Small Molecule transmitters
 Mono Amines
• Acetylcholine
• Serotonin
• Histamine
Catecholamines
• Dopamine
• Norepinephrine
• Epinephrine
 Amino acids
• Glutamate
• Gamma-amino butyric acid (GABA)
• Glycine
2. Large Molecule Transmitters
Neuropeptides
•Substance P and Other Tachykinins
•Opoid Peptides
3. Other Chemical Transmitters
• Cannabinoids
• Gases (NO)

12. Neurotransmitter Source Site of Synthesis
Acetylcholine Choline CNS, parasympathetic nerves
Serotonin
Tryptophan
CNS, chromaffin cells of the gut, enteric cells
GABA Glutamate CNS
Histamine Histidine hypothalamus
Epinephrine
Tyrosine adrenal medulla, some CNS cells
Norepinephrine
Tyrosine CNS, sympathetic nerves
Dopamine Tyrosine CNS
Nitric oxide Arginine CNS, gastrointestinal tract

14. C.CATECHOLAIMNES

15. • Cholinergic
• Dopaminergic
• Noradrenergic
• Serotonergic

17. Functions
• In PNS
– Induces skeletal muscle
contraction
• In CNS
– Arousal and reward
– Enhancement of
sensory perceptions
when we wake and in
sustaining attention

18. Functions
• Behavior and cognition
• Voluntary movement
• Motivation, punishment
and reward
• Mood, attention, working
memory, and learning

19. Functions
• Affects amygdala, where
attention and responses
are controlled
• Increasing heart rate,
triggering the release of
glucose from energy stores
• Increasing blood flow to
skeletal muscle
• Increases the brain's
oxygen supply

20. Functions
• Mood
• Cognition
• Sleep
• Memory Processing

21. • Schizophrenia
• Parkinson’s Disease
• Alzheimer’s Disease
• Dementia
• Bipolar Disorder
• Depression
• Sleep Disorder

22. • Neurotransmitters are the wonder
chemicals of human body.

23. • URL1-http://en.wikipedia.org/Neurotransmitters
• Barren et al. (2005), Ganong’s Review of Medical Physiology (23rd
Ed.), Elsevier, pp 223-297