Neurotransmitters Flashcards
What are neurotransmitters?
Neurotransmitters are chemicals released by neurons that travel through the synapse
What is a neuron?
A specialised cell designed to transmit information to other nerve cells, muscle, or gland cells. They are joined at the axon and dendrite, where synapses are used to pass signals from one neuron to another.
What are synapses?
The points of contact between neurons where information is passed from one neuron to the next.
What is ‘action potential’?
The electrical impulse travelling through the neuron is called the action potential
What are ‘neural networks’?
Series of connected neurons. Information travels along these networks that enable us to do things.
What is a ‘terminal button’?
The part of the neuron, located on the Axon that releases chemicals.
What are agonists?
Any chemical that stimulates a receptor site and causes an action potential is an agonist. All neurotransmitters are agonists for receptor sites.
What are antagonists?
Drugs that block the receptor site and do not allow the neurotransmitter to do its job, so no action potential is sent down the neuron. SSRIs like fluoxetine, for example, block receptors sites on the presynaptic neuron and prevent the re-uptake of serotonin as a treatment for depression.
What are receptors?
Found on the post-synaptic membrane of a neuron, receive neurotransmitters
What is dopamine?
Neurotransmitter
What is dopamine responsible for?
Acting on areas of the brain that are responsible for voluntary movement.
What drugs can dopamine be affected by?
Amphetamines and cocaine
What is the function of dopamine?
The ‘reward’ system - involved in emotional responses, and the hippocampus, which is involved in memory processing
What did Fisher’s study find in relation to dopamine?
Areas of the brain associated with dopamine production and reception were activated when the P’s looked at images of people they loved.
What is acetylcholine (ACh)?
The first neurotransmitter to be discovered (1914).
Where is acetylcholine produced?
ACh is produced in several locations within the brain and it has been observed that some of these regions are damaged in the early stages of Alzheimer’s disease.
What is ACh responsible for in the central nervous system (CNS)?
In the CNS, ACh is believed to be involved in learning, memory, and mood.
How can neurotransmitters be applied to real life?
The drugs tacrine and donepezil, currently marketed as Alzheimer’s drugs, work to increase the effectiveness of ACh in the brain.
Alzheimer’s Disease
Alzheimer’s disease is the most common cause of dementia among older people. Dementia is the loss of cognitive functioning: thinking, remembering, and reasoning, to such an extent that it interferes with a person’s daily life and activities.
Alzheimer’s Disease - ACh
Acetylcholine is particularly prevalent in the hippocampus. The hippocampus of ‘normal’ people contains high concentrations of acetylcholine, but low concentrations are found in people with Alzheimer’s disease.
What was the aim of the study by Rogers and Kesner?
To determine the role of acetylcholine in the formation of spatial memory.
What was the first part of the procedure of the study by Rogers and Kesner?
They had 30 rats explore a maze by placing food in one of the corners. Once the rats were familiar with the maze, and no longer were afraid of the environment the rats were randomly allocated to one of two conditions.
What were the two conditions that the rats were placed into in the study by Rogers and Kesner?
The rats were either injected with scopolamine or with a saline solution (control) ten minutes before running the maze.
What is scopolamine responsible for?
Scopolamine blocks the acetylcholine receptor sites and thus inhibits any response.
What was the point of using a placebo in the study of Rogers and Kesner?
To make sure that getting an injection alone was not responsible for a change in memory. An injection could result in an increase in adrenaline which would be a confounding variable.
Where were the injections made in the study of Rogers and Kesner?
Directly into the hippocampus.
