Question | Answer |
What are the anatomical structures of the reward pathway? | ventral tegmental area (midbrain), nucleus accumbens (ventral forebrain), prefrontal cerebral corex, medial forebrain bundle, amygdala, hypothalamus |
Where is the ventral tegmental area? | midbrain |
Where is the nucleus accumbens? | ventral forbrain |
What is the purpose of the reward/pleasure pathway? | the brain reward system reinforces activities essential to species survival. |
What does the release of dopamine do? | leadds to subjective feelings of well being |
What do drugs of abuse affect? | affects the brain reward pathway |
How do drugs of abuse alter the reward/pleasure pathway? | when drugs of abuse are repeatedly used, they may commandeer the reward system driving compulsory drug use to exclusion of other adaptive activities. they will increase dopamine neurotransmitter levels or block the re-uptake of stimulation of release |
When are abusers likely to relapse? | during times of high stress |
How is the hypothalamus linked to the pleausre pathway during times of stress? | the hypothalamus responds to stress by altering hormone release which affecgts the reward pathway. |
explain the relationship of dopamine and the pleasure pathway | dopamine receptors are metabotropic so it binds to a g-protein as a scondary messenger. After dopamine is released, it binds to post-synaptic receptors and is then swept back into the pre-synaptic terminal by re-uptake pumps |
Where does cocaine bind? | nucleus accumbens, VTA and caudate nucleus |
How does cocaine affect the reward pathway? | increases synaptic dopamine in the reward pathway by binding to dopamine transporters to prevent-reuptake |
What happens with successive release of cocaine? | down-regulation of recetpors by successive exposures to the drug and then require higher concentrations to achieve the desired effects |
cocaine stimulates structures of teh brain that are designed to promote what? | survival of the species. cocaine stimulates the brain reward system more effectively than the behaviors in the reward system that is designed to reinforce |
What does cocaine reduce in the brain? | metabolic activity and the brain uses less glucose |
What are the two mechanisms that amphetamines affect the reward pathway? | decrease teh re-uptake of dopamine and directly increase teh neuronal release of dopamine |
Where does heroine bind? | nucleus accumbens, vta, caudate nucleus, thalamus, brainstem and spinal cord |
How does heroine influence the reward pathway? | indirectly by inhibiting GABA neurons that would normally inhibit dopamine neurons. There is nothing to inhibit dopamine production so there is an increase in dopamine |
What is Ih current? | depolarizes cells in the brainstem, spinal cord and thalamus that will reduce action potential firing and reduces the perception of pain |
Where does THC bind? | caudate nucleus, cingulated gyrus, neocortex, hippocampus, cerebellum |
How does THC affect the reward pathway? | inhibits GABA and thereby there is no dopamine release inhibition |
What is ecstasy a derivative of? | amphetamine |
where does ecstasy bind? | neocortex, hypothalamus, basal ganglia, amygdala and hippocampus |
What pathway does ecstasy affect? | serotonin |
How does serotonin affect teh neocortex? | cognition |
How does serotonin affect the limbic system? | memory and mood |
What is the origin of the serotonin pathway? | raphe nucleus |
how is serotonin removed from the synapse? | serotonin re-uptake pumps |
How does ecstasy affect the serotonin pathway? | blocks serotonin re-uptake pumps as well as making those pumps bring serotonin back |
does ecstasy affect the dopamine pathway? | yes, the same way as the serotonin pathway |
what happens after taking ecstasy | depression-like feeling and irritability |
What are the long term effects of ecstasy | serotonis is reduced and thereby reducing metabolite. Serotonin transporeters are reduced and the terminals degenerate |