Neurotransmitters Flashcards
1
Q
Define neurotransmitter
A
- chemical messengers which transmit information from one neuron to another.
- can be affected by agonists (chemicals that enhance the action of neurotransmitters) and antagonists (chemicals that counteract neurotransmitters).
2
Q
Describe neurotransmission
A
- an electrical signal comes down from the axon and generates action potential
- synaptic vesicles contain neurotransmitters to move towards pre-synaptic membrane
- neurotransmitters diffuse across the gap and attaches(binds) to the post-synaptic membrane(complementary shapes)
- after crossing the synapse, neurotransmitters fit into receptor sites on the post-synaptic membrane, like a key in a lock
- reuptake–reabsorption of neurotransmitter
3
Q
Define inhibitory neurotransmitters
A
- stop the impulse, preventing it from crossing the synapse.
- produce calming effects on the brain.
4
Q
Define excitatory neurotransmitters
A
- allow the impulse to cross the synapse.
- produce stimulating effects on the brain.
5
Q
Study 1
A
Martinez and Kesner (1991) - acetylcholine & memory formation
6
Q
Aim 1
A
to measure the role of acetylcholine in the formation of spatial memory.
7
Q
Procedure 1
A
- 30 rats were placed in the maze individually and completed the maze (maze had a reward of food at the end).
- rats were given their respective treatments 10mins before running the maze.
1. injected with scopolamine (antagonist - blocks the ACH receptor sites and inhibits response)
2. not injected or altered in any form (control). - time taken for individuals rats to complete the maze were recorded.
8
Q
Results 1
A
- rats in condition 1 took longer to complete the maze.
- Acetylcholine may plays an important role in the consolidation of spatial memory as the rats in control group (with more ACH) took shorter time to complete the maze.
9
Q
Evaluation 1
A
- lab enviroment: high scientific rigour, results are highly accurate.
- strong applications - the development of treatment form dementia or alzheimer’s disease.
- animals selected are similar to humans (can serve as models for human physiology and behaviour).
- a reductionist approach to understand memory - didn’t explain the complexity of types and process of memory consolidation
10
Q
Study 2
A
Antonova et al (2011) - acetylcholine on encoding spatial memory
11
Q
Procedure 2
A
- participants were 20 male adults with a mean age of 28.
- they were randomly allocated to the two conditions respectively (70-90mins before the experiment, they were either):
1. injected with scopolamine
2. injected with placebo. - the participants were then put into an fMRI where they were scanned while playing “Arena task” - a virtual reality game in which the participants need to navigate around an “arena” with the goal of reaching a pole.
- it will then go blank for 30s.
- when the arena reappeared, the participants would have to use their spatial memory to determine how to get to the location o the pole.
12
Q
Results 2
A
- participants injected with scopolamine (antagonist) demonstrated a significant reduction in the activation of the hippocampus compared to when they received a placebo.
- thus ACH could play a key role in the encoding of spatial memories in humans.
13
Q
Evaluation 2
A
- double-blind procedure: control for research & participant bias.
- the sample size was small: need replication to decide whether the results are reliable.
- no ethical concerns as no physical and psychological harms were done to the participants.
14
Q
Behaviour
A
acetylcholine on encoding spatial memory.
15
Q
Aim 2
A
to measure the role of acetylcholine in the formation of spatial memory