2c. Neurotransmission Flashcards
Neurotransmission
Electrochemical process through which electrical impulses are transferred from pre-synaptic to post-synaptic neurons with the help of neurotransmitters
What are the 3 things that can happen when a neurotransmitter is released?
- It fits into receptor of post-synaptic neuron and generates nerve impulse
- Left in synapse and broken down by an enzyme
- Reabsorbed by pre-synaptic neuron through re-uptake
Neurotransmitters
Natural chemical messengers that transmit information from one neuron to another
Examples of major neurotransmitters
Serotonin, dopamine, acetylcholine, norepinephrine
Excitatory neurotransmitters
They increase the likelihood of an action potential being fired by depolarizing the neuron
Example of excitatory neurotransmitters
Acetylcholine
Inhibitory neurotransmitters
Decreases likelihood of action potential being fired by hyperpolarizing the neuron
Example of inhibitory neurotransmitters
GABA
Agonists
Chemical that binds to receptor sites on post-synaptic neurons causing it to fire
Examples of agonists
All neurotransmitters are agonists for their own receptors so acetylcholine, serotonin etc.
Endogenous agonists
The brain’s natural chemicals. Inside the body
Example of endogenous agonists
Neurotransmitters
Exogenous agonists
Chemicals from the external environment, not produced by the body
Examples of exogenous agonists
- Drugs
- Alcohol binds with dopamine receptor sites
Antagonists
Drugs that block receptor site and do not allow neurotransmitter to do its job i.e. no action potential
Antagonist for acetylcholine
Scopolamine
Antanova: Aim
To see whether scopolamine affected hippocampal activity during creation of spatial memory
Antanova: Research method + design
- Lab experiment
- Repeated measures
- Double blind study
Antanova: Participants
- 20 healthy male adults were randomly assigned to two conditions
Antanova: Conditions
One group received a scopolamine injection while the other received a placebo
Antanova: Procedure
- After injection, they were told to wait for an hour- 1.5 hours
- They were given a task of plating a difficult VR game
- Game involved finding a pole and then find it again from starting point (spatial memory)
- Performed task inside an fMRI and brain activity was measured 6 times
- Returned 3-4 weeks later and redid experiment with the other injection they didn’t receive
Antanova: Results
- When compared to placebo, scopolamine showed no significant difference in time taken to complete the task or number of errors made
- Their fMRI did show a significant decrease in hippocampal activity
Antanova: Evaluation
- May have experienced stress from injection or enclosed space
- Activity may not have been the best to measure, only saw a difference because of fMRI
