Cannabis Lecture Notes

Cannabis

Introduction

  • The lecture will cover cannabis, incorporating information beyond the textbook. Research will be updated, clarifying any additions to the material.

THC

  • THC is the primary psychoactive compound in cannabis.
  • It is concentrated in the resin produced by the plant's flowers and leaves.
  • Resin contains a mix of compounds contributing to the plant's effects.
  • The potency of cannabis preparations (oils, edibles) depends on the amount of resin present, with higher amounts typically indicating higher THC levels and stronger psychoactive effects.

Pharmacology of Cannabis

  • Cannabis contains over 500 chemicals, with about 100 unique to the plant, known as cannabinoids.
  • The most well-known cannabinoids are THC and CBD.
    • THC: Psychoactive, produces a high.
    • CBD: Non-psychoactive, potential therapeutic benefits like reducing anxiety and inflammation.
    • Earlier research discussed CBD's effectiveness for anxiety.

Endocannabinoid System

  • Cannabinoids interact with the body's endocannabinoid system -- a natural system with receptors, and endogenous cannabinoids, and proteins that transport and synthesize endocannabinoids.
  • When substances like THC are consumed, they interact with this natural system.
  • The system consists of two main types of cannabinoid receptors: CB1 and CB2.
CB1 Receptors
  • Primarily located in the central nervous system (brain and spinal cord).
  • Regulate mood, memory, appetite, and pain perception.
  • THC binding produces psychoactive effects, influencing emotional states.
  • CB1 receptors significantly impact long-term potentiation (LTP) in the hippocampus.
    • LTP is essential for learning and memory: lasting increase in synaptic connection strength between neurons after a period of time.
    • Neurons that fire together, wire together.
  • Cannabinoids like THC binding to CB1 receptors in the hippocampus can inhibit neurotransmitter release, reducing synaptic activity.
    • This impairs LTP, making it harder for neurons to strengthen connections, affecting memory formation.
  • Newer studies (mostly animal studies) focus on this process.
  • Research is complex, with varied findings, including null findings; more research shows impact on memory.
CB2 Receptors
  • Primarily found in the peripheral nervous system and abundant in immune cells (e.g., lymph nodes).
  • Present in smaller amounts in other tissues, including the brain.
  • Modulate inflammation without producing psychoactive effects.
  • Help the immune system by reducing inflammation and regulating immune responses.
  • Cannabinoids binding to these receptors can lower the production of inflammatory molecules, preventing excessive inflammation and tissue damage.

Endogenous Cannabinoids

  • The body has receptors to interact with cannabinoids because it produces naturally occurring substances that interact with these receptors.
Anandamide
  • Naturally occurring cannabinoid.
  • Acts as a partial agonist at both CB1 and CB2 receptors.
    • Binds to receptors but activates them less fully, leading to moderate effects in mood, pain, and appetite.
2-AG
  • Full agonist at both CB1 and CB2 receptors.
    • Fully activates these receptors, producing stronger effects.
  • Present at higher levels in the body compared to anandamide.
  • Plays a significant role in various physiological processes.
  • More research is available on anandamide.

Cannabinoid Activity

  • Cannabinoids can reverse the typical neurotransmitter process: release from the postsynaptic neuron, traveling through the cleft, and engaging the presynaptic receptors.

Absorption

  • Smoking:
    • THC is rapidly absorbed into the bloodstream, travels quickly to the brain, and disperses throughout the body.
    • Produces noticeable and quicker mood-altering effects (euphoria, relaxation).
    • Effects typically peak in 5-10 minutes.
  • Oral (Edibles):
    • Slower absorption through the digestive system.
    • Peak period is 60-90 minutes after ingestion.