A map of the brain, in the language of the clinic.

I. Main Regions

PAG (periaqueductal gray)

RAGE · FEAR · PANIC/GRIEF · LUST · PLAY

Core role

A ring of gray matter in the midbrain surrounding the cerebral aqueduct (aqueduct of Sylvius), which connects the third and fourth ventricles. In Panksepp’s model, the shared alarm/action center of all the emotional systems — divided into columns (dorsomedial, dorsolateral, lateral, ventrolateral), each column running a different emotional-behavioral program.

Connections

Dorsal columns: RAGE (attack) and the active-defense end of FEAR. Lateral column: active escape, “fight/flight”. Ventrolateral column: freezing, the “playing dead” that overlaps with the dorsal vagal system. The separation call of PANIC/GRIEF and some components of LUST also pass through the PAG.

The PAG is the single most frequently mentioned structure in the book — and this is no coincidence: it is concrete evidence for Panksepp’s thesis that “emotions are subcortical”. That different emotional systems are coded in the same region, in different columns, shows that they are not separated by sharp borders but are neighbors in a compact architecture — this is the anatomical ground for why, in the clinic, overactivation of one system also triggers its neighbor (for example, intense FEAR leaping into RAGE).

II. Main Pathways

Opioid and endocannabinoid systems

not wanting (dopamine) but liking (hedonic tone)

What it carries

The non-dopamine half of the classic “reward” story. Endogenous opioids (endorphins, enkephalins) and endocannabinoids code how much an experience is “liked” (hedonic tone) rather than how much it is “wanted” — dopamine carries wanting, opioids/cannabinoids carry satisfaction.

Connections

Concentrated in the hedonic hot spots of the nucleus accumbens; also connected with the PAG, the PANIC/GRIEF circuit (soothing separation pain) and the PLAY circuit.

That wanting and liking are separate systems is the key to the book’s themes of addiction and insatiability: a person can intensely want something (a substance, a relationship, a behavior) (dopamine high) yet no longer take any pleasure from it (opioids low) — this is the neural explanation of the clinical picture “I want it so much but I’m never satisfied”.

II. Main Pathways

Fronto-limbic maturation pathway

vmPFC/OFC → amygdala and subcortical structures

What it carries

The process by which inhibitory projections descending from the PFC (especially the vmPFC/OFC) to the amygdala and other subcortical structures strengthen over the years after birth through myelination and synaptic reorganization. At birth this pathway is immature; its regulatory function becomes clear only toward adolescence — regulation is supplied from outside (by the caregiver).

Connections

The speed and degree of this pathway’s strengthening are directly linked to the quality of early CARE — the experience of safe, predictable regulation supports the maturation of this circuit.

This pathway is the direct anatomical counterpart of one of the book’s most fundamental theses — “regulation first comes from outside, then is internalized”. Almost every developmental transition in the book (a change of stage, the maturation of a defense mechanism, therapeutic change) means this pathway growing a little stronger.

Closing

Panksepp’s systems, Freud’s stages, Erikson’s crises and Mahler’s subphases, discussed one by one throughout the book, are in fact produced by different combinations of a shared, limited number of anatomical components (the PAG, amygdala, hypothalamus and a few cortical areas) and a handful of pathways that connect them.