Problems with synapases

Question 1

What is dopamine?

Answer 1

Neurotransmitter that causes parkinsons disease

Question 2

Describe parkinsons disease?

Answer 2

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

Question 3

What are the symptoms of parkinsons disease?

Answer 3

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

Question 4

What are the treatments of parkinsons disease?

MAO inhibitors -

Answer 4

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

Question 5

What are the treatments of parkinsons disease?

L-Dopa

Answer 5

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

Question 6

What are the treatments of parkinsons disease?

Agonists

Answer 6

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

Question 7

What are the treatments of parkinsons disease?

Gene therapy

Answer 7

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

Question 8

What are the treatments of parkinsons disease?

Deep brain stimulation

Answer 8

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

Question 9

Describe excess dopamine

Answer 9

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

Question 10

What is serotonin?

Answer 10

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

Question 11

Describe depression

Answer 11

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

Question 12

What are the causes of depression?

Answer 12

Not completely understood but its probably a multifactorial condition

Question 13

Why do people become depressed?

Answer 13

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

Question 14

What drugs are used to treat depression

Answer 14

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

Question 15

How do drugs affect synaptic transmission?

Answer 15

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

Question 16

What is MDMA?

Answer 16

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

Question 17

How does MDMA affect synapses?

Answer 17

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

Question 18

What are the side effects of MDMA?

Answer 18

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