Pharmacodynamic Tolerance

Question 1

Tolerance

Answer 1

• When you take substance repeatedly, body gets overabundance of neurotransmitter into system.
• Ex. cocaine results in too much dopamine in cleft
• Brain doesn’t like being overwhelmed and develops neuroadaptation called downregulation.
• Downregulation - a reduction in the number of dopaminergic post-synaptic receptors.
• With fewer post-synaptic receptors the brain feels like its receiving the same level of dopamine as before cocaine use. People don’t want same level. They want same effect from first time.

Question 2

Monoamine reuptake transporter

Answer 2

transporter is found on axon terminal

• responsible for taking durgs/neurotransmitters out of the cleft and return it to the vesicles to be used later
• prevent too much NT staying in cleft for too long