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2nd Year: Drugs and the Mind > Cannabis > Flashcards

Flashcards in Cannabis Deck (35)
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1
Q

What are endocannabinoids?

A

Endogenous neurotransmitters that stimulate CB1 and 2 receptors.

2
Q

What kind of receptors are CB1 and CB2 and where are they found?

A

Pre-synaptic GPCRs: CB1 is found in the CNS and CB2 in the PNS.

3
Q

What are endocannabinoids involved in? List 4 things.

A
  1. Pain
  2. Mood
  3. Memory
  4. Appetite
4
Q

Describe the transmission of endocannabinoids.

A

Retrograde transmission: they are released by the post-synaptic neuron and act on the pre-synaptic neuron.

5
Q

What affect do endocannabinoids have on the pre-synaptic neuron?

A

They reduce the amount of neurotransmitter released

6
Q

How do endocannabinoids reduce the amount of neurotransmitter released by the pre-synaptic neuron?

A

Cannabinoid binding to the CB1 receptor causes an inhibition of adenylate cyclase. This causes a reduction in the production of cAMP, which means reduced activation of PKA. This affects K+ and Ca2+ channels, i.e. it is harder to generate APs and release NTs.

7
Q

What is arguably the most prevalent endocannabinoid?

A

Anandamide.

8
Q

Endocannabinoids are hydrophilic. True or false?

A

False: they are extremely lipophilic and stick to cell membranes.

9
Q

Cannabis is a class B drug. True or false?

A

True.

10
Q

Cannabis falls into the depressant category, although it is a weak depressant. What is a depressant?

A

A drug that affect inhibitory neurotransmission.

11
Q

What is the active ingredient in cannabis?

A

THC or delta-9-tetrahyrdocannabinoid.

12
Q

THC is a synthetic chemical. True or false?

A

False: it is naturally occurring in cannabis plants.

13
Q

Cannabis only comes in one form and is always the same strength. True or false?

A

False: it comes in multiple forms that vary in strength, e.g. resins, leaves etc.

14
Q

What does THC do in the body?

A

It binds the CB1 receptor as it is structurally similar to endocannabinoids. This is competitive inhibition.

15
Q

How does THC affect inhibitory neurotransmission?

A

GABA neurons have CB1 receptors, thus THC binds these and reduces the release of GABA.

16
Q

What effect does reduced GABA transmission have on dopamine?

A

It increases the release of dopamine: normally GABAergic neurons inhibit dopamine release. When GABA is inactivated by THC dopaminergic neurons become more active than normal.

17
Q

What does increased dopamine create?

A

A increased sense of reward: dopamine released by the VTA causes dopamine release in the nucleus accumbens, this is the brain’s reward pathway.

18
Q

List 8 effects of cannabis.

A
  1. Slight euphoria
  2. Relaxation
  3. Amplified sensory perception
  4. Inhibited balance and motor activity
  5. Munchies
  6. Nausea/vomiting
  7. Anxiety and paranoia
  8. Confused temporal memory
19
Q

How does cannabis produce euphoria?

A

Due to its effects in the reward pathway.

20
Q

The amplified sensory perceptions attributed to cannabis use can be mildly hallucinogenic. Why is this?

A

Increased dopamine is associated with psychosis, e.g. the positive symptoms of schizophrenia.

21
Q

Which sensory perceptions are amplified the most by cannabis?

A

Sound, smell, taste and touch.

22
Q

Which areas of the brain are affected by cannabis to produce the motor inhibition?

A

The basal ganglia and cerebellum.

23
Q

Why can cannabis make you nauseous and vomit?

A

Dopamine controls the CTZ or chemoreceptor trigger zone that controls nausea and vomiting.

24
Q

Which areas of the brain are affected to produce anxiety/paranoia and memory deficits?

A

The hippocampus.

25
Q

How long do the effects of cannabis last?

A

~3hours.

26
Q

How long is cannabis traceable in the body for?

A

~2weeks.

27
Q

Why is prolonged cannabis usage thought to decrease attention, learning/memory and cognitive abilities?

A

The CB1 receptors in the brain arteries become sensitised to cannabinoids and thus become non-functional. This can cause a reduction in blood flow to the brain, resulting in less oxygen and glucose for brain cells.

28
Q

Does cannabis cause amotivation?

A

It is not clear whether cannabis is a causal factor or an accompaniment to a lazy lifestyle.

29
Q

Does cannabis cause psychosis?

A

It may increase the risk in those that are already predisposed. For example dopamine over-activity is thought to be behind the positive symptoms of schizophrenia, plus the loss of CB1 receptors in the brai arteries appear to induce symptoms of cognitive schizophrenia.

30
Q

List 3 therapeutic uses of cannabis?

A
  1. Antiemetic
  2. Cancer pain
  3. Parkinson’s and MS
31
Q

Why is cannabis useful as an antiemetic?

A

It affects dopamine levels and dopamine regulates the CTZ.

32
Q

Why is cannabis not regularly used as an antiemetic?

A

Because the withdrawal and side effects are unpleasant.

33
Q

What kind of benefits does cannabis give cancer patients? List 6.

A
  1. Analgesia
  2. Increased appetite
  3. Mood elevation
  4. Sedation
  5. Amnesia
  6. Muscle relaxation
34
Q

Why might cannabis be useful for Parkinson’s and MS?

A

It provides muscle relaxation that counteracts spasticity.

35
Q

How does cannabis provide analgesia?

A

It activates inhibitory Mu receptors, thus diminishing the pain response.