Neurotransmission

Question 1

Neurons

Answer 1

The NS is a system of neurons. A neuron consists of 3 parts; the body, dendrites & the axon. Where the axon of 1 neuron approaches another neuron, a synapse is formed. The neurons send electrochemical messages to the brain so that ppl can respond to stimuli, either from the environment or internal changes in the body. The process by which these messages are sent is called neurotransmission.

Question 2

Neurotransmission process

Answer 2

The electrical impulse that travels along the body of the neuron is called an action potential. When an action potential travels down a body, or axon, of a neuron, it releases neurotransmitters that are stored in the neuron’s terminal buttons. The neurotransmitters are then released into the synapse

Question 3

Neurotransmitter definition (say after process)

Answer 3

the body’s natural chemical messengers that transmit info from 1 neuron to another. After crossing the synapse, the neurotransmitters fit into receptor sites on the post-synaptic membrane. Once message is passed on, the neurotransmitters are either broken down by an enzyme or reabsorbed by the terminal buttons in a process called reuptake.

Question 4

Action potential

Answer 4

the electrical impulse that travels along the body of the neuron

Question 5

Neurotransmitters on behaviour

Answer 5

• have shown to have a wide rage of effects o behaviour

Question 6

What happens when the neurotransmitter binds to the receptor on the post-synaptic neuron

Answer 6

• this changes the next neurons electric potential & contributes to building up an impulse

Question 7

Acetylcholine

Answer 7

Plays a role in the consolidation of memory in the hippocampus

Question 8

What classifies a chemical as either antagonist or agonist?

Answer 8

chemicals are either antagonist or agonist, depending on what they do to the pre-synaptic or post-synaptic receptor site

Question 9

Is acetylcholine agonist or antagonist?

Answer 9

Agonist

Question 10

What are antagonists?

Answer 10

drugs that block the receptor site & do not allow the neurotransmitter to do its job, so not action potential is sent down the neuron
e.g scopolamine for acetylcholine

Question 11

Rogers & Kesner aim

Answer 11

to determine the role of acetylcholine in the formation of spatial memory

Question 12

Study for agonists & antagonists

Answer 12

Rogers & Kesner

Question 13

Rogers & Kesner IV

Answer 13

whether rats were given scopolamine or placebo

Question 14

Rogers & Kesner DV

Answer 14

time and errors made to learn maze

Question 15

Rogers & Kesner procedure

Answer 15

30 rats had to acclimate to a Hebb Williams maze by place food in 1 of the corners

once rats were familiar w the maze- no longer afraid of the environment, the experiment could begin

Rats were randomly allocated into 2 condition.
G1: injected with scopolamine which is an antagonist for acetylcholine receptors, blocks acetylcholine from binding to its receptors.
G2: injected with saline solution (placebo)
the injections were made directly into the hippocampus

Encoding of memory was assessed by the average number of errors made on the first 5 trials of day 1, compared to the last 5 trials of day 1.

To assess retrieval, the average number of errors on the first 5 trials of day 2 was compared to the last 5 trials of day 1.

Question 16

Roger & Kesner results

Answer 16

• the scopolamine group took longer & made more mistakes in the learning of the maze - there was a higher number of mistakes made on the last 5 trials of day 1
  however, it did not appear to have an effect on the retrieval on memories that had already been created.

Question 17

Roger & Kesner conclusion

Answer 17

it appears that acetylcholine may play an important role in the consolidation of spatial memories

Question 18

Rogers & Kesner evaluation

Answer 18

• controlled experiment w the use of a placebo condition to avoid the effect of confounding variables
• able to establish a cause & effect relationship; however, it is a reductionist approach to understanding memory . There are several types of memory & the process of memory consolidation is very complex
• research could one day lead to the development of treatments for people suffering from dementia or alzheimer’s disease
• biologists believe that animals can serve as models for human physiology & behaviour, however, questionable the generalisation of these findings

Question 19

What are agonists?

Answer 19

Chemical substances that mimic or enhance the effects of a neurotransmitter on the receptor sites of the next cell, increasing or decreasing the activity of that cell

Question 20

Scopolamine

Answer 20

Antagonist that blocks receptor sites of acetylcholine on the post-synaptic neuron.

Question 21

Excitatory neurotransmitter

Answer 21

increase the likelihood of a neuron firing by depolarising the neuron
excitatory neurotransmitters include acetylcholine