All parts of the brain › Functions › Crying

What part of the brain controls crying?

The tears come from the pons: its superior salivatory nucleus sends the signal out along the facial nerve, through the greater petrosal nerve and the pterygopalatine ganglion, to the tear (lacrimal) gland. For emotional tears, a mouse study found oxytocin neurons in the hypothalamus’s paraventricular nucleus driving that nucleus. Which higher parts turn a feeling into tears is not yet mapped. [1][2][3]

The pons and the hypothalamus lit in red on a 3D model of the brain, seen from the front left and above

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Lit: whole parts; region borders not drawn.

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All 2 parts are lit together. Drag to turn, pinch or scroll to zoom, tap a part on the brain or a name in the list to focus it; .

The superior salivatory nucleus is a region on the pons, not a separate shape. The 3D model has no shape for it, so the whole pons is lit; the region’s exact border is not drawn.

The paraventricular nucleus is a region on the hypothalamus, not a separate shape. The 3D model has no shape for it, so the whole hypothalamus is lit; the region’s exact border is not drawn.

Crying: 2 parts lit

Pons and hypothalamus. Tap one to see where it is and what it does.

The parts and their roles

Holds the superior salivatory nucleus, the facial nerve’s gland-driving nucleus, which lies dorsolateral to (behind and to the side of) the facial motor nucleus; its lacrimal neurons send fibres out with the facial nerve and, by the greater petrosal nerve, to the pterygopalatine ganglion and on to the tear gland, which makes most of the watery part of the tear film. The trigeminal nerve, which carries the eye-surface signals behind reflex tears, enters the brain here too. [1][2][3] Where is the pons?
In mice, oxytocin neurons in its paraventricular nucleus project to oxytocin-receptor neurons in the “lacrimation centre” of the superior salivatory nucleus; switching them on or off with light changed tear secretion, and tearing that went with mothering, a painful stimulus or recalling a frightening memory was damped when that oxytocin link was silenced. [3] Where is the hypothalamus?

Named areas on the lit gyri

The superior salivatory nucleus, on the : A small group of parasympathetic neurons in the reticular formation of the pons, beside the facial motor nucleus; it drives the tear gland and, through the facial nerve’s chorda tympani, the submandibular and sublingual salivary glands. [1][3]
The paraventricular nucleus, on the : A nucleus of the hypothalamus beside the third ventricle that holds oxytocin-making neurons; in the mouse study these are the ones that reach the superior salivatory nucleus. [4][3]

How they work together

There are three kinds of tears. Basal tears keep the eye wet at about 0.5–2.2 µL a minute; irritation can raise the rate up to about 100-fold, to some 300 µL a minute (reflex tears); emotional (psychic) tears are the ones shed in emotional states. In a day a person makes about 0.75 to 1.1 grams of tears, less with age. [2][5]
Reflex and emotional tears enter the circuit by different roads: when the trigeminal nerve is cut, reflex tears stop but emotional tears do not. Both end on the same parasympathetic route, which works the tear gland with acetylcholine. [2]
Anatomical studies in animals find inputs to the superior salivatory nucleus from the frontal cortex, basal ganglia, thalamus and paraventricular hypothalamus, as well as from the trigeminal nerve. Only the hypothalamus is lit, because it is the one input whose link to tearing has been tested directly; the others are known only from anatomy. [3]
Emotional tears carry larger amounts of some hormones, including prolactin, adrenocorticotropic hormone and leu-enkephalin, and of potassium and manganese. [5]
Honest limit: the oxytocin route was shown in mice, in a 2022 preprint, and emotional tearing is often assumed to be unique to humans, so it is a lead, not the full human circuit. The page covers how tears are made and sent, not the crying face, voice or breathing, and nothing about any one person. [3]

Laughter, the other loud emotional outburst, has its own page; it lights the hypothalamus and pons as well, with the brainstem’s periaqueductal grey and the cingulate gyrus. [6] What part of the brain controls laughter?

The same facial nerve works the face muscles of a crying face: the facial expressions page lights the motor cortex and the pons, where the facial motor nucleus sits. [1] What part of the brain controls facial expressions?

Sources

Facts describe anatomy and normal function only. A part lit here takes part in crying; it does not do it alone, and it does other jobs too. The 3D model is the adult male BodyParts3D brain (credits and licence); on it the brainstem includes the midbrain, pons and medulla, so lighting the brainstem lights all three.