Lecture 26- Marijuana

Question 1

What does the endocannabinoids system do to neurotransmitters?

Answer 1

• inhibits the release of many neurotransmitters including
• glutamate
• GABA
• noradrenaline
• dopamine
• and serotonin

Question 2

Where are endocannabinoids made, stored, and released? Why?

Answer 2

• in the postsynaptic neuron
• because endocannabinoid system follows retrogradetransmission

Question 3

Why are endocannabinoid receptors on the presynaptic neuron?

Answer 3

• receptors (metabotropic) are on the presynaptic terminal to inhibit the release of whatever neurotransmitter the presynaptic neuron would typically release

Question 4

Is marijuana considered a dirty drug?

Answer 4

• cannabinoid receptors (CB1 and CB2) are found all over the brain and NS
• But, bc cannabinoids only work on these specific receptors, marijuana is not considered a dirty drug

Question 5

In what ways do marijuana’s acute physicological effects very per user?

Answer 5

• strength
• intensity
• and duration

however, generally quite benign

Question 6

Acute physiological effects- cardiovascular (specifically eyes)

Answer 6

• conjunctiva (bloodshot eyes)
• due to vasodilation
• apparent after around 1 hour
• dose-dependent

Question 7

acute physiological effects- cardiovascular

Answer 7

• icreased heart rate and BP
• apparent after around 20 minutes and lasts around 1 hour
• dose-dependent

Question 8

Acute physiological effects: motor

Answer 8

• decreased motor activity
• drowiness, although decreases REM sleep with higher doses
• however, dose not decrease talkativeness lol hahahaha

Question 9

Other acute physiological effects

Answer 9

• dry mouth
• thirst
• changes in body temp
• respiration changes
• hunger
• nausea
• headache
• dizziness

Question 10

Chronic physiological effects- respiratory

Answer 10

• decreased proper lung function that may be reversible
• marijuana cigs contain more tar and carcinogens than tobacco, and is held in lungs longer than tobacco smoke
• but, difficult to determine which contributes more as marijuana users typically smoke cigarettes

Question 11

Emphysema marijuana vs tobacco

Answer 11

• 93% of marijuana smokers
• 66% of tobacco smokers

Question 12

Chronic physiological effects- cardiovascular

Answer 12

• no significant long-term effects in healthy users
• acute effects potentially dangerous in individuals w heart disease

Question 13

Chronic physiological effects- immune

Answer 13

• no significant long-term effects even though it can have immunosuppressant effects

Question 14

Chronic physiological effects-Reproductive

Answer 14

• decreased sperm count/motility
• nonovulatory menstrual cycles

Question 15

Learned psychological effects of marijuana

Answer 15

• mechanical: learning to inhale and hold the smoke to maximize absorption
• perception: learning to perceive the physical and psychological effects
• labeling- learning to label the effects that are pleasant

Question 16

Who is most sensitive to cannabis effects?

Answer 16

experienced users are more sensitive than newbies

Question 17

Behavioral psychological effects of marijuana

Answer 17

• decreased psychomotor activity
• relaxed/tranquil feeling
• some feel excited/restless (novice users)
• keener perception- likely anecdotal, but no scientific basis (however, decreased sensitivity to pain)
• impaired reaction times- inconclusive yet critical for driving

Question 18

Sexual function-psychological effects

Answer 18

• varied effects- increased pleasure in some and decreased desire in otheres
• long-term use can lead to impotence in men and reduced sex drive in women

Question 19

Cognitive psychological effects

Answer 19

• impaired stm at low doses
• adoescents may be more vulnerable
• decreased (lengthened) perception of time
• impaired judgement and attention/vigilance

Question 20

What is the mechanism underlying impaired stm on weed?

Answer 20

• unknown, byt likely due to reduced NT, including impaired LTP and LTD
• LTP and LTD- strengthening or weakening of synaptic connections- neural correlates of learning and memory

Question 21

emotional psychological effects of marijuana

Answer 21

• typically carefree and relaxed feeling (euphoric, content, happy, and excited)
• anxiety/dysphoria more common than expected (around 1/3): suspiciousness/paranoia in some cases (usually ineperienced users)

Question 22

Marijuana use and mental disease link

Answer 22

• some evidence links marijuana use and mental disease (anxiety, depression, achizophrenia/psychosis)- inconclusive
• more likely that the drug use unmasks an issue already genetically present
• or, that the drug use is correlated w mental illness (but not the cause

Question 23

Is marijuana reinforcing?

Answer 23

• bc CB receptors are found everywhere it is difficult to understand how cannabis activates the reward pathway, so overall unsure

Question 24

Tolerance

Answer 24

• animal models show tolerance develops to marijuana
• human studies less clear- factors include dose and use duration
• mechanisms of tolerance unclear but likely in heavy users

Question 25

Withdrawal symptoms from weed

Answer 25

• symtpoms include sleep disturbances, nausea, and restlessness
• associated w sustained heavy use

neuroadaptations do occur following chronic use

Question 26

Amotivational syndrome

Answer 26

• not seen in all marijuana users, and also seen in non marijuana users
• so, likely a combination of pre-existing personality characteristics and some drug effects

Question 27

Is weed a gateway drug?

Answer 27

• vast majority of marijuana users do not go on to use hard drugs
• but 90% of cocaine users have tried/used marijuana
• if there is a stepping stone, it is likely alcohol and nicotine (alc/nic to marijuana to hard drugs)

Question 28

What is the correlative vulnerabilities theory?

Answer 28

right combination of circumstances along with positive experience w a drug can lead to misuse