neurones and synapses

Question 1

synaptic transmission

Answer 1

1. Action potential comes down axon to terminal
2. Vesicles full of Neurotransmitters move to the edge of the cell and release NT into the gap
3. The NT drifts across the gap and bonds to a receptor (lock and key mechanism)
4. When enough are filled then a new AP/nerve impulse starts on the next cell
5. Any used/excess NT are reabsorbed to the pre-synaptic membrane

Question 2

action potential

Answer 2

When the neurone is at rest the inside is
negatively charged
2. When the neuron is stimulated, ions enter and leave - once you get to -55mv the AP begins
3. The ions continue to switch places and it
becomes less negative inside (depolarised)
4. At +35/40 the AP fires and the signal propagates
5. It then goes through repolarisation where ions switch again and it becomes negative again inside
6. Finally it goes through hyperpolarization where it is extra negative inside for a moment (during the refractory period) before going back to the resting state

Question 3

acetylcholine

Answer 3

(C7H16NO2) is linked to memory and cognitive thought. Low levels of this is linked to Alzheimer’s. It is also important for motor control and emotions such as anger and sexuality

Question 4

Norepinephrine (noradrenaline)

Answer 4

Norepinephrine (noradrenaline) is responsible for fight or flight, treats ADHD. It is also involved in sleeping and dreaming.

Question 5

dopamine

Answer 5

(C8H11NO2) is associated with pleasure. It is also linked to addiction. It is linked to illnesses like Schizophrenia and many other things in the body e.g.controlling the menstrual cycle

Question 6

serotonin

Answer 6

Happiness and good mood, along with melatonin it regulates sleep/wake, hunger and pain. Low levels are linked with depression and anxiety.
Low serotonin has been linked to aggression, assault, arson, murder, and child beating.

Question 7

GABA

Answer 7

is associated with suppressing the activity of the neurons it contacts, reducing the probability that they will fire.

Question 8

Glutamate

Answer 8

is involved in most aspects of normal brain function including cognition, memory and learning. Helps to increase the probability of neurons firing. Works almost like the opposite of GABA.