The parts list from lesson two, filled in completely — a timeline with more steps than 'plant, receptor, body's own version', the receptors and enzymes CB1/CB2 alone don't cover, and a close reading of the one messenger his slide singles out: anandamide.
A timeline with more steps
●EstablishedLesson one told the discovery in three beats. His own slide draws it with more steps between them, and they are worth having in order: 1964, Δ9-THC isolated. 1988, the first pharmacological evidence of a specific cannabinoid binding site in rat brain tissue, via radioligand assay — two years before that receptor was actually cloned. 1990, CB1 cloned. 1992, anandamide isolated. 1993, CB2 cloned. 1995, 2-AG identified, and the word endocannabinoid itself enters use.
1996 closes the loop lesson two describes without dating it: FAAH — the enzyme that ends anandamide's signal — is cloned. By 1996 the system had a receptor, two accepted messengers, and a named off switch, in that order. Discovery followed the logic of the system, not the other way around.
"엔도라는 말이 생물학에서는 많이 사용되는데 엔돌핀을 생각하시면 됩니다. 생물의 몸 안에 있는 모르핀이 엔돌핀인 거죠. 비슷하게, 엔도카나비노이드는 사람 몸 안에 있는 카나비노이드다." His own teaching analogy for the word itself, from the lecture audio: endorphin is to morphine what endocannabinoid is to cannabinoid — the body's own version of a compound named after the plant that led researchers to it.
"THC도 1964년에 처음 분리가 됐거든요. 그러니까 어떻게 보면 불법이 되고 나서야 이 식물에 대해서 연구가 조금 더 본격적으로 일어나기 시작한 거죠. 그래서 사실상 법을 만들었던 사람들이나 그동안 법을 집행을 해온 사람들도 제대로 몰랐던 거예요." His own observation on why the discovery ran 'backwards', the theme lesson one is named for: cannabis was made illegal before the plant was well understood, and serious research into what it actually was followed criminalisation rather than preceding it — the lawmakers and enforcers, by his account, didn't know either.
The rest of the receptor family
●EstablishedCB1 and CB2 are the classical pair lesson two covers. His slide's full table adds three more groups. Ionotropic: TRPV1 through TRPV4, TRPA1, TRPM8 — heat- and pain-sensing ion channels that several endocannabinoids and phytocannabinoids act on directly, not through CB1/CB2 at all. Novel or 'orphan' G-protein-coupled receptors: GPR3, GPR6, GPR12, GPR18, GPR55, GPR92, GPR119 — still being characterised, several with signalling that doesn't resemble CB1/CB2's. Nuclear receptors: PPARα, PPARγ, PPARδ — which is how cannabinoids reach gene transcription and metabolism, not only fast synaptic signalling.
The table also names non-cannabinoid receptors that endocannabinoids or phytocannabinoids happen to bind anyway: 5-HT1A, 5-HT3, the glycine receptor, adenosine A2A and A3, alpha-2 adrenergic receptors, mu and delta opioid receptors. This is the honest reason isolating 'the' effect of a given cannabinoid is hard — several of them are promiscuous ligands acting on unrelated receptor families at once, and a claim that names only CB1 or CB2 is usually incomplete rather than wrong.
"요새는 CB3의 수용체도 발견이 돼서 연구가 되고 있고." His lecture audio (clip 35) names a third classical-family member the slide table didn't: CB3, described only as recently discovered and under active research — held at emerging tier here since nothing further about its distribution or function is stated on this clip.
The rest of the parts: messengers, enzymes, transport
●EstablishedBeyond anandamide and 2-AG, his slide names a peptide class — pepcans, hemopressin-related — and two closely related lipids, PEA (palmitoylethanolamide) and OEA (oleoylethanolamide), structurally similar to anandamide but acting mostly outside CB1/CB2. Further modulators named: N-arachidonoyl amino acids, pregnenolone (which acts as a brake on CB1 signalling specifically, a hormonal buffer rather than a receptor ligand), and lipoxin A4.
Synthesis: DAGLα and DAGLβ make 2-AG; NAPE-PLD makes anandamide; PTPN22 is also listed on the synthesis side. Degradation: MAGL is 2-AG's main route; FAAH1 and FAAH2 handle anandamide; ABHD6 and ABHD12 are secondary routes for 2-AG; NAAA and the COX-2/LOX oxidative pathways are listed as further degradation routes — and COX-2/LOX are also inflammation-signalling enzymes in their own right, which the next lesson's inflammation pathway leans on directly. Transport — how a lipid moves from where it's made to where it acts, and to its own degrading enzyme, without a vesicle to carry it — is the one part of this table his slide names without settling; the mechanism is still an open question, not a gap in this transcription.
Anandamide's name, and how much of it you have
◗EmergingAnanda — bliss, in Sanskrit — plus amide, its chemical class. Lesson one already gives the name. What his slide adds is that how much of it you have is not the same for everyone: FAAH activity, which sets how fast anandamide is cleared, varies by a gene variant whose frequency differs by population — his slide cites approximate carrier rates of 21% in European Americans, 14% in East Asians, and 45% in Nigerians. Lower FAAH activity means anandamide clears more slowly, which in the studies behind this figure associates with a higher pain threshold and higher self-reported happiness.
That is a population-level pharmacogenetic finding, not a prediction about any one person, and this course holds it at that tier deliberately — the honest reading is 'this varies by more than lifestyle', not 'your ethnicity determines your baseline mood'.
His lecture audio for this slide (clip 35) confirms the same two figures — 14% and 45% — in his own voice, and also includes a spoken aside drawing a broader conclusion from them about ethnicity and capacity for happiness, citing a ~2015 study's popular interpretation. On his own instruction (2026-09-21) that aside is deliberately not carried into this lesson: by his own account it was an impression from meeting people of varied backgrounds, not a conclusion he stands behind, and the paragraph above already states the boundary correctly — the gene-frequency finding, not what any interpretation stretches it into.
Turning the dial on purpose
●EstablishedLesson two's closing line was that FAAH and MAGL are 'where a great deal of drug development has aimed' — raising your own endocannabinoid levels rather than introducing a plant agonist. His slide's diagram names the two standard research tools for exactly that: JZL184, which blocks MAGL and raises 2-AG, and URB597, which blocks FAAH and raises anandamide. Both are research compounds, not medicines available to write a prescription for, and their place in this lesson is mechanistic, not aspirational.
What rising anandamide is associated with
●EstablishedHis slide's brain diagram maps the direction of effect by receptor: through CB1, rising anandamide associates with lower depression, lower pain, lower anxiety — and lower memory, the same trade-off lesson three names as useful forgetting rather than pure deficit. Separately through CB1: higher feeding, higher sleep. Through CB1 and CB2 together: lower neuro-inflammation, the mechanism the next lesson gives a full pathway.
This is the wiring diagram underneath what lesson three already claimed in outline — appetite, pain, memory, mood. Nothing here changes that lesson's tiers; it gives the same claims a specific circuit rather than a general statement of 'the system modulates this'.
Before moving on
- Lesson two called FAAH and MAGL 'as much a part of the system as the receptors'. Having now seen the fuller table — ionotropic channels, orphan GPCRs, nuclear receptors, a whole second messenger class — does that claim still feel proportionate, or does the system look larger than that framing suggested?
References
- Gaoni, Y. & Mechoulam, R. (1964). Isolation, Structure, and Partial Synthesis of an Active Constituent of Hashish. Journal of the American Chemical Society, 86(8), 1646–1647.●1964 — already the opening date in lesson one.
- Devane, W. A., Dysarz, F. A. III, Melvin, L. S., Johnson, M. R. & Howlett, A. C. (1988). Determination and characterization of a cannabinoid receptor in rat brain. Molecular Pharmacology, 34(5), 605–613.1988 — the radioligand evidence for a cannabinoid binding site, ahead of CB1's cloning.
- Matsuda, L. A. et al. (1990). Structure of a cannabinoid receptor and functional expression of the cloned cDNA. Nature, 346, 561–564.1990 — CB1 cloned, already cited in lesson one.
- Devane, W. A. et al. (1992). Isolation and structure of a brain constituent that binds to the cannabinoid receptor. Science, 258(5090), 1946–1949.1992 — anandamide, already cited in lesson one.
- Munro, S., Thomas, K. L. & Abu-Shaar, M. (1993). Molecular characterization of a peripheral receptor for cannabinoids. Nature, 365, 61–65.1993 — CB2 cloned, already cited in lesson two.
- Mechoulam, R. et al. (1995). Identification of an endogenous 2-monoglyceride, present in canine gut, that binds to cannabinoid receptors. Biochemical Pharmacology, 50(1), 83–90.1995 — 2-AG, already cited in lesson two.
- Cravatt, B. F. et al. (1996). Molecular characterization of an enzyme that degrades neuromodulatory fatty-acid amides. Nature, 384(6604), 83–87.1996 — FAAH cloned, closing the timeline this lesson adds.
From his teachingThis lesson is drawn from Dr. Kwon's own teaching material, edited for the screen.