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Flashcards in Problems with synapases Deck (18):

What is dopamine?

Neurotransmitter that causes parkinsons disease


Describe parkinsons disease?

Dopamine sectreting neurones in the basal ganglia dia which normally release dopamine in the motor cortex
less dopamine to open sodium channels to depolarise it so fewer action potentials


What are the symptoms of parkinsons disease?

Stiffness of muscles, tremor of muslces, slowness of movement, poor balance, walking problems


What are the treatments of parkinsons disease?
MAO inhibitors -

inhibits monoamine oxidase which breaks down dopamine in the brain increasing the availiability of dopamine


What are the treatments of parkinsons disease?

Dopamine cannot be fiven as it cannot cross into the brain from the bloodstream
L-Dopa is a precursor of dopamine
L-Dopa is converted into dopamine


What are the treatments of parkinsons disease?

Drugs that activate the dopamine receptor directly which mimic the role of dopamine in the brain binding to dopamine receptors at synapses triggering action potentials


What are the treatments of parkinsons disease?
Gene therapy

Genes for proteins that increase dopamine production and promote the growth and survival of nerve cells are inserted into the brain


What are the treatments of parkinsons disease?
Deep brain stimulation

Surgery used to treat symptoms of the disease so can reduce medication


Describe excess dopamine

Major cause of schizophrenia
Treated with drugs that block binding of dopamine to its postsynaptic receptor sites which similar to dopamine in structure but unable to stimulate receptors


What is serotonin?

Neurotransmitter - if theres a lack of it it causes depression
Neurones that release it are in the brain stem, their axons extend into the cortex, the cerebellum and spinal cord


Describe depression

Feelings of sadness, anxiety, hopelessness, loss of interest in activities and reduced energy levels


What are the causes of depression?

Not completely understood but its probably a multifactorial condition


Why do people become depressed?

Fewer nerve impulses than normal are transmitted around the brain which may be related to low levels of neurotransmitters
Pathways involving serotonin have a number of abnormalities - molecules needed for serotonin synthesis are in low conc but theres more serotonin binding sites


What drugs are used to treat depression

MAOI's were used but not used anymore due to side effects
Selective Serotonin Reuptake Inhibitor - inhibits reuptake of serotonin for synaptic clefts
Prozac - maintains a higher level of serotonin and so increases rate of nerve impulses in serotonin pathways


How do drugs affect synaptic transmission?

Neurotransmitter synthesised and stored
Neurotransmitter released
Neurotransmitter-receptor binding
Neurotransmitter reuptake
Neurotransmitter breakdown


What is MDMA?

Drug (ecstasy) that affects thinking, mood and memory as well as anxiety and altered perception


How does MDMA affect synapses?

MDMA increases concentration of serotonin in the synaptic cleft by binding to molecules in presynaptic membrane that transports serotonin back into the cytoplasm
This prevents the removal from synaptic cleft which could increase the amount of serotonin outside the cell


What are the side effects of MDMA?

Clouded thinking, agitation and disturbed behaviour]Sweating dry mouth, increased heart rate, fatigue and muscle spasms, hyperthermia as MDMA can affect the control of body temp