Chapter 6: Drugs and Hormones

Question 1

Where is the blood-brain barrier?

Answer 1

capillaries in the brain consisting of astrocytes and endothelial cells (tight junctions)

Question 2

What parts of the brain do not have a blood brain barrier?

Answer 2

• area postrema: allows toxic substances in the blood to trigger a vomiting response
• pineal gland: enables hormones to reach it and modulate the day-night cycles controlled by this structure
• pituitary gland: secretes hormones into the bloodstream so there is an opening so these hormones can get through the body

Question 3

What is the blood brain barrier?

Answer 3

specialized system of brain microvascular endothelial cells (BMVEC) that shields the brain from toxic substances in the blood, supplies brain tissues with nutrients, and filters harmful compounds from the brain back to the bloodstream.

Question 4

Agonists vs Antagonists

Answer 4

Agonist: Substance that enhances the function of a synapse

Antagonist: Substance that blocks or decreases the function of a synapse

Affects ANY of the stages of the neural impulse

Question 5

Agonists and antagonists of the acetylcholine synapse

Answer 5

Agonists
- Choline-rich diet increases ACh
- Black widow spider venom promotes release of ACh
- Nicotine stimulates receptors (similar shape to ACh so it fits)
- Physostigmine and organophosphates block inactivation, anti-alzheimer’s drugs

Antagonists
- Botulism poisoning toxin blocks release
- Curare (poison darts) blocks receptors

Question 6

What differentiates your body between having a sensitization response vs habituation response?

Answer 6

Primed based on life experience and genotype

Question 7

Sensitization

Answer 7

• The occasional drug taker may have an increased responsiveness to successive equal doses
• Much more likely to develop with periodic use

Question 8

Tolerance

Answer 8

Tolerance: a learned behavior results when a response to a stimulus weakens with repeated presentations

Results in: increased enzymes, fewer receptors, and learned tolerance

Question 9

What underlies the behavioral effects of drugs that affect the GABA synapse?

Answer 9

widespread reduction of neuronal firing

Question 10

What binds with the GABA receptor?

Answer 10

alcohol and benzodiazepines

Question 11

What binds with the Opioid receptor?

Answer 11

Any endogenous (naturally occurred) or exogenous (taken) compound that binds to opioid receptors to produce morphine-like effects (sleeping and pain-relief)

Naloxone binds with the receptor to block opioids from binding on the synapse

Question 12

Dopaminergic antagonists

Answer 12

medically prescribed for schizophrenia and drug-induced psychosis (thorazine, abilify, clozaril)

Question 13

Opiodergic antagonists

Answer 13

ex: naltrexone and naloxone.

Question 14

What is the brain pathway associated with addiction?

Answer 14

begins in the ventral tegmental area (VTA) and continues on to the mesolimbic dopamine pathway

Question 15

What causes addiction and dependence?

Answer 15

• Wanting-liking theory (mesolimbic dopamine vs opioid neurons)
• Pleasure and dependence: habitual drug users initially experience pleasure but then endure psychological and physiological withdrawal symptoms as the drug wears off
• Dopamine overloads your brain

Question 16

What are risk factors in addiction?

Answer 16

• Environmental factors and ACEs are associated with an increase risk of drug initiation and addiction
  These factors changes the structure of the brain
• Females are twice as sensitive to drugs as males
• Women are more likely than men to abuse nicotine, alcohol, cocaine, amphetamine, opioids, cannabinoids, caffeine, and PCP

Question 17

Adenosinergic antagonist

Answer 17

ex: caffeine

• Binds to adenosine receptors without activating them
• Adenosine increases throughout the day
• Inhibits an enzyme that ordinarily breaks down the second messenger, cyclic adenosine monophosphate (cAMP)

Question 18

Cholinergic agonist

Answer 18

ex: nicotine and cognex

Question 19

GABAergic agonists

Answer 19

ex: alcohol + valium, xanax, klonopin

Question 20

Glutamatergic antagonists

Answer 20

Ex: PCP and Ketamine + Namenda

Question 21

Dopaminergic agonists

Answer 21

ex: cocaine, amphetamine, methamphetamine + Adderral, Ritalin, L-dopa

Question 22

Serotonergic agonists

Answer 22

ex: Peyote, LSD, DMT, MDMA + Zoloft, Prozac

Question 23

Opiodergic agonists

Answer 23

ex: Opium, Morphine, Heroin + morphine, codeine, oxycodone (Percocet), fentanyl, methadone

Question 24

Cannabinergic agonists

Answer 24

Ex: THC + Sativex

Question 25

Classes of hormones

Answer 25

Steroids, Peptide, Homeostatic, Gonadal, Glucocorticoids

Question 26

Two types of stress responses and hormones involved

Answer 26

Fast acting: primes the body immediately for fight or flight (epinephrine)

Slow-acting: both mobilizes the body’s resources to confront a stressor and repairs stress-related damage (cortisol)

Question 27

Ending a stress response

Answer 27

Hippocampus is well suited to detecting cortisol in the blood and instructing the hypothalamus to reduce blood cortisol levels

Prolonged stress reduces the hippocampal ability to reduce cortisol levels

Question 28

Steroid Hormone

Answer 28

Fat-soluble chemical messenger synthesized from cholesterol. Can result in gene transcription, DNA activation

Question 29

Anabolic-androgenic steroids

Answer 29

Synthetic hormones related to the male sex hormone testerone that have both muscle-building (anabolic) and masculinizing (androgenic) effects

Question 30

Peptide Hormone

Answer 30

• affects the target cell’s physiology

Ex: insulin, growth hormone

Question 31

Homeostatic hormones

Answer 31

Maintain internal metabolic balance and regulation of physiological systems - mineralocorticoids such as aldosterone (blood volume)

ex: leptin and gherlin (done eating vs hunger)

Question 32

Gonadal Hormone

Answer 32

Control reproductive functions, sexual development, behavior

ex: Estrogen, testosterone, progesterone

Question 33

Glucocorticoid Hormone

Answer 33

• Secreted in times of stress, important in protein and carbohydrate metabolism

ex: Cortisol, corticosterone