Recap of Neurobiology

Question 1

How quickly do non-myelinated axons carry information? What about myelinated ones?

Answer 1

Non-myelinated: 2 meters/second

Myelinated: 100 meters/second

Question 2

What is the implication of the differing speed of information in myelinated vs. non-myelinated axons?

Answer 2

Myelinated axons are for reflexes since information is needed to travel much faster

Question 3

Which type of receptor is faster: ionotropic or metabotropic? Why?

Answer 3

Ionotropic, because no second messengers are needed to execute an action

Question 4

How does studying reinforcement schedules help us understand addictive behaviours?

Answer 4

Because with schedules such as progressive reinforcement, we can see how hard someone is willing to work for the reward (more work = more reward = more addictive)

Question 5

Why are metabotropic receptors necessary?

Answer 5

Because they effectuate long-term change in the brain

Question 6

What are the three steps of every metabotropic receptor?

Answer 6

1. Second messengers are activated
2. Kinases are activated by the second messengers
3. Transcription factors are altered because of the kinases

Question 7

What is the key role of kinases? What does this achieve?

Answer 7

Kinases all phosphorylate, which then activates the material and enables it to bind to other things now

Question 8

What are the rewarding effects of abused drugs mediated by?

Answer 8

The natural reward circuitry in the brain (the dopamine pathway)

Question 9

Which dopamine pathway is associated with the rewarding effects of drugs?

Answer 9

The mesocorticolimbic pathway

Question 10

Describe the mesocorticolimbic pathway.

Answer 10

Dopaminergic neurons originate in the VTA and project to the prefrontal cortex

Question 11

How do drugs act on the dopamine system?

Answer 11

1. They can increase the firing rate of dopamine neurons (ex. morphine)
2. They can prevent the reuptake of DA (ex. cocaine)
3. They can reverse the DA transporter (ex. amphetamine)