Drugs Flashcards
What is the dopamine system?
Pathway in the brain which operates on the neurotransmitter dopamine, the release of which leads to feelings of rewards.
What is the nucleus accumbens?
An area of the Mid-brain associated with the brains reward system.
What is the Ventral Tegmental?
An area of the Mid-brain associated with the brains reward system and the origin of dopaminergic activity
What is Euphoria?
Intense pleasurable feeling often called a ‘high’.
What is Dysphoria?
Intense dissatisfaction, anxiety or depression.
Apart from obvious reasons, Biologically why is it bad to take drugs?
A drug like Heroin increase the ammount of Dopamine io n the brain to cause intense euphoria. However, the brain then produces less natural dopamine to balance the levels of dopamine in the brain. After a while the brain naturally gets used to producing less dopamine and so does so without the person taking drugs. This means that when the person doesn’t take drugs they feel less happy due to the lack of dopamine. They are reliant on drugs to get that feeling of euphoria and thus take more and more to get the same feeling as the brain naturally produces less and less.
How does Alcohol someone consuming it?
Alcohol has a depressant effect on the nervous system; it acts to inhibit neural transmission by increasing the action of GABA (an inhibitory neurotransmitter).
How does Opioids e.g heroin or morphine effect someone taking it?
It reduces GABA activity, which leads to over activity of dopaminegic neurotransmission in the reward pathways of the brain.
How does Amphetamines e.g. Meth effect someone taking it?
It increases dopamine and noradrenaline in the synapse by changing the re-uptake process so that it works in reverse. They force the release of these neurotransmitters, can block re-uptake, and in high doses can inhibit their breakdown by enzymes.
How does Cocaine effect a user?
Increase activity in the dopamine pathway by blocking the re-uptake of dopamine.
What study supports what can happen when the reward pathways are stimulated?
Olds and MiIlner
What is a weakness of the biological explanation of how drugs work?
Transmission is very complex and there is more than one reward pathway in the reward system and more than one brain region involved. Thus this explanation seems very simplistic.
What is another weakness of the biological explanation of how drugs work?
It is hard to study the mode of action of recreational drugs at the synapse. Brain scanning has helped but brain scans cant see to the level of transmission. For example, info about Cannabis has focused on GABAergic and glutamatergic transmission because they are two transmitters that can be studied using electrophysiological techniques.
How does Nicotine effect users?
It targets aspects of the dopamine pathway increasing the amount and transmission of dopamine by blocking the enzyme that breaks it down. It also mimics acetylcholine and binds to nicotinic receptors.
How does Cannabis effect users?
Cannabis bind to cannabinoid receptors and block them which prevents the neurotransmitter released from the pre-synaptic neuron sending the message into the post-synaptic neuron.The hippocampus has a lot of these receptors and so it prevents activity in this part of the brain which effects memory and also stops specific neurons from preventing dopamine production in the rewards system.
