Cannabis and the Brain Flashcards
Q: What age range of Canadians have the highest global rates of cannabis usage?
A: 15-24
Q: What percentage of Canadians aged 18-24 frequently engage in binge drinking?
A: 82%
Q: What is early initiation of cannabis use associated with? (4)
A: Anxiety, depression, ADHD, psychosis
Q: List some factors that contribute to the maturation of the adolescent brain.
A: Heredity and environment; age (10-25); sex hormones; physical, mental, economical, psychological status; surgical interventions; sleep; nutritional status; pre and postnatal insult; pharmacotherapy; drug abuse
Q: Give examples of neurotransmitter systems that are developed during adolescence (4).
A: Dopamine system; endocannabinoid system; glutaminergic receptors; serotonergic receptors.
Q: True or false: Cannabis may impact synaptic pruning.
A: True
Q: How might cannabis impact synaptic pruning?
A: unknown mechanism but ECS is known to play a role in regulating synaptic plasticity.
Q: What can issues with synaptic pruning lead to?
A: Increased mental health challenges.
Q: What has research shown about cannabis use and cognition?
A: That cannabis use can lead to deficits in cognition.
Q: What is included under the term ‘cognition’? (6)
A: Perceiving, judging, reasoning, learning, evaluating, remembering
Q: Give a specific example of how acute cannabis use can impact cognition.
A: Impairs inhibition and promotes impulsivity.
Q: What was the key finding of the article ‘Brain Function Outcomes of Recent and Lifetime Cannabis Use’?
A: That 63% of heavy users had reduced brain activity during a working memory task.
Q: What is working memory?
A: Holding information (Short term).
Q: What type of models are typically used in pre-clinical cannabis research?
A: Rodents (mice or rats)
Q: How are rodent models useful in cannabis research? What are their limitations?
A: Can assess changes in receptors, proteins, etc. but limited ability to assess cognition and other ‘human’ traits.
Q: Give examples of pre-clinical methods of measuring synaptic density. (4)
Electron microscopy, western blot, immunohistochemistry; proteomics
Q: What is the gold standard of pre-clinical synaptic density measurements and what is its use?
Electron microscopy - provides direct visualization of the synapse.
Q: What is the use of the western blot?
A: Synaptic protein measurements.
Q: What is the use of immunohistochemistry?
A: Morphology and density of dendritic spines, expression of proteins
Q: What is the use of proteomics?
Protein expression.
Q: What is the primary method of synaptic density measurement in vivo?
A: Positron emission tomography
Q: How does PET work?
A: Uses a radioactive tracer to image protein markers of interest in vivo. It has a rotating scanner that is sensitive to the marker(s) of interest.
Q: When can PET be used?
A: Pre-clinically and in humans.
Q: What is synaptic vesicle glycoprotein 2A (SV2A)?
A: A transmembrane presynaptic protein of synaptic vesicles.
Q: Describe the expression of SV2A.
A: Ubiquitously expressed across all synapses.
Q: What molecule is SV2A highly correlated with, and why is this important?
A: Synaptophysin, the gold standard marker of synaptic density.
Q: Differentiate between pre-synaptic and post-synaptic proteins.
Pre = ‘sending’ part of the synapse
post = ‘receiving’ part of the synapse.
Q: Give examples of pre-synaptic proteins.
Synaptophysin, vGlut, vGAT, synapsin, SV2A, Bassoon, SNAP-25, Syntaxin, vAMP, neurexin
Q: Give examples of post-synaptic proteins.
A: PSD-95, neuroligin, homer, shank, gephyrin
Q: What is [18F]SynVesT-1?
A radiotracer for SV2A.
Q: Currently, how many studies have looked at CUD and SV2A using PET imahing?
2
Q: True or false: there are numerous studies looking at mental health disorders and cannabis use disorder and in youth specifically.
A: False, there are no studies of the kind.
Q: Why is [18F]SynVesT-1 preferred over [11C]UCB-J?
Better half-life and improved kinetics
Q: What four steps need to be taken to begin research?
come up with research question, grants, ethics approval; finding staff/resources
Q: What do you need to do for ethics approval?
Need to outline all study components, justify why they are being done, and how participant safety will be upheld.
Q: What is an informed consent form?
A: Ensures that research participants are fully aware and consent to all study components.
