This presentation summarizes key information about four major neurotransmitters: dopamine, GABA, glutamate, and glycine. It describes how each neurotransmitter is synthesized, the receptors it acts on, its functions in the brain and body, and potential implications when levels are too high or low. Dopamine is involved in reward and motor control and impacts conditions like Parkinson's and schizophrenia. GABA is the main inhibitory neurotransmitter and prevents overexcitement. Glutamate is the primary excitatory neurotransmitter influencing cognition and memory. Glycine also acts as an inhibitory neurotransmitter and is used in various biosynthesis pathways. References are provided at the end to cite sources of information.

1. SUBMITTED BY
MOHD MUZAHID
M.PHARM(Pharmacology) 1st year
SUBMITTED TO
MOHD KHUSHTAR
Asst. Professor
Integral University, Lucknow
Dopamine, GABA, Glutamate And Glycine
A Presentation on
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2. What is Neurotransmitter ?
 Neurotransmitter is a chemical substance that acts as the mediator for the
transmission of nerve impulses from one neuron to another neuron through
synapse.
 It a messenger of neurologic information from one cell to another.
 Neurotransmitters are packaged into synaptic vesicles presynaptic side of a
synapse.
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3. TYPES OF NEUROTRANSMITTERS
EXCITATORY
Glutamate
Aspartate
Nitric oxide
INHIBITORY
Glycine
GABA
Serotonin
Dopamine
BOTH
Acetylcholine
Nor epinephrine
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4. Dopamine
 Is synthesized in three steps from the amino acid tyrosine.
 Associated with reward mechanisms in brain.
 Generally involved in regulatory motor activity, in mood, motivation and attention.
 Schizophrenics have too much dopamine.
 Patients with Parkinson's Disease have too little dopamine. Dopamine
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5. Receptor
 Dopamine acts through D1 , D2 as well as adrenergic alpha and B1 receptors ( But
not B2)
 D1 and D2 receptors are the most abundant and widespread in areas receiving a
dopaminergic innervation ( namely the striatum ,limbic system, thalamus and
hypothalamus) as are D2 receptors, which also occur in the pituitry gland
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6. Mechanism of Action
At low dose (0.5 to 3 mic /kg /min ):-
 Selectively activates dopamine specific receptors in the renal and splanchnic circulation.
 Increase blood flow in these region.
 Low dose dopamine also directly affects renal tubular epithelial cells.
At high dose (> 10 mic /kg / min ):-
 Dopamine produces a progressive activation of alpha receptors in the systemic and pulmonary
circulation resulting in progressive pulmonary and systemic vasoconstriction
 This vassopressor effect by virtue of increasing ventricular afterload
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7. Clinical Uses
 Dopamine is often used in situation where both cardiac stimulation and peripheral vasoconstriction
desired such as Cardiogenic shock
 Also used to correct the hypotension in the septic shock .But nor epinephrine become the preferred
vassopressor in this condition
 Low dose is often used in an attempt to prevent or reverse acute renal failure
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8. γ-AMINO BUTYRIC ACID (GABA)
 Synthesized directly from glutamate.
 GABA is the most important inhibitory neurotransmitter
 Present in high concentrations in the CNS, preventing the brain from becoming overexcited.
 If GABA is lacking in certain parts of the brain, epilepsy results.
GABA
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9. Receptor
 GABA exerts its effects by two types of receptors
1-GABAA
2-GABA B
 They differ in their pharmacological & biochemical properties
 GABAA is ionotropic & GABA B is metabotropic
 GABA receptors are channel receptors
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10. Function of GABA
 Relieving anxiety.
 Improving mood.
 Regulating the release of sex hormones.
 Stabilizing blood pressure.
 Relieving pain.
 lower elevated blood sugar levels in diabetics.
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11. Glutamate
 It is an amino acid
 It the most commonly found excitatory neurotransmitter in the brain.
 It is involved in most aspects of normal brain function including cognition, memory and learning.
 Glutamate is formed from α – ketoglutarate, anintermediate of Kreb’s cycle.
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13. Glutamate receptors
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14. Glycine
 It is simplest aminoacid.
 Nonessential and glucogenic.
Formation of glycine:
 From serine
 From threonine
 By glycine synthase reaction
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15. Metabolic functions of glycine:
Glycine is used for biosynthesis of
1. Heme
2. Purine ring
3. Creatine
4. Glutathione
5. As a conjugating agent
6. Glycine as neurotransmitter
7.Glycine as a constituent of protein
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16. References;
 Knut Schmidt Nielsen, Animal Physiology – Adaptation and environment, 4th edition, Cambridge
University Press, U.K
 Richard.W.Hill (1976) Animal Physiology, 2nd edition, Harper Collin’s Publishers, New York.
 http://www.sciencedaily.com/releases/2011/12/111205 165907.htm
 http://www.columbia.edu/cu/psychology/courses/1010/mangels/neuro/transmission/transmission.html
 http://www.chemistryexplained.com/NeNu/Neurotransmitters html#b
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17. THANK YOU
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