Neurotransmitters in Brain and the Diseases

7/29/2019 Neurotransmitters in Brain and the Diseases

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NEUROTRANSMITTERS IN BRAINAND THE DISEASES


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The control and coordination

of all activity in brain

relies on SYNAPSES

Synapses depend on NT

Imbalances in naturally occurring brain chemicals cancause problems, as can drugs by passing the bloodbrain barriers

The endothelial cells forming the capillaries in brain aretightly joined --- form a barrier --- protect the brain


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There are nearly 50 NT

Functions of two are discussed

DOPAMINE &SEROTONIN

The effects of ECSTASY are used to illustrate how

drugs can affect synapses


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DOPAMINE & PARKINSONS DISEASE

Dopamine is NT secreted by neurons , located in themidbrain

In PD , the neurons that secrete dopamine in thebasal ganglia die


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SYMPTOMS OF PD

Stiffness of muscles

Tremor of the muscles

Slowness of movement

Poor balance

Walking problems

Other problems could be

difficulty in speech and breathing , depression


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TREATMENTS FOR PD

Slowing the loss of dopamine -- by use of selegiline ---inhibits Monoamine oxidase which breaks downdopamine

Dopamine cannot be given , as it cants cross into brain

from blood stream so L- Dopa

a precursor can begiven can be converted into dopamine , increasingthe concentration

Dopamine agonists

mimic the role of dopamine

Gene therapy research still going on to inject directproteins


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SEROTONIN & DEPRESSION

Serotonin imp for determining a persons mood

Neurons that secrete serotonin cover major areas ofbrain

Lack of serotonin causesDepression

It is multifactorial genetic

Environmental factors


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TREATMENT FOR DEPRESSION

SSRI Selective Serotonin Reuptake Inhibitor blocks

reuptake of serotonin

Prozac maintains high level of

Serotonin


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HOW DRUGS AFFECT SYNAPTICTRANSMISSION

Synapses can be disrupted by

A chemical that can bind to receptor sites on post

synaptic neurone

Chemicals prevent the release of NT , block oropen ion channels or inhibit a breakdown enzyme


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EFFECT OF ECSTASY

Chemical name is MDMA methylene dioxy methyl

amphetamine

Ecstasy affect thinking ,

mood and memory

Can also cause anxiety

, altered perceptions

( hallucinations )


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HOW ECSTASYAFFECTSSYNAPSES

Increases the concentration of serotonin

This is done by binding to molecules reuptake ofserotonin prevents removal from synaptic cleft

Side effects clouded thinking , disturbed behaviour ,sweating , dry mouth , increased HR

High BP , muscle breakdown , kidney failure etc

Long term effects --- insomnia , depression ,psychological problems


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Documents

Neurotransmitters in Brain and the Diseases