Why does too much cheese make you have vivid dreams?

Cheese is a rich source of neuroactive compounds including the monoamine called "tyramine", which has provokes the release of adrenaline.

When we go to sleep a small part of the brainstem, called the locus coeruleus, switches on and through its connections with other regions of the brain triggers rem (rapid eye movement) sleep, which is associated with dreaming.

The name locus coeruleus is latin for "blue place" and if you cut across the brainstem with a knife you can clearly see the blue-coloured nerve cells that comprise this region. The cells are pigmented by neuromelanin, the neurological equivalent of a suntan. Neuromelanin is made as a biproduct in the synthesis of the nerve transmitters noradrenaline (a relative of adrenaline) and dopamine. These chemicals are derived from tyrosine, the same stuff used to make melanin in skin cells.

So the locus coeruleus, which triggers dream-sleep, uses noradrenaline as its nerve transmitter. Since cheese contains tyramine, which has the ability to potentiate the action of adrenline-like nerve transmitters, it is likely that eating cheese before bed fools the brain into thinking that there is more adrenaline waashing around than normal, making dreams more vivid.

Famously, when some of the first antidepressants were invented they worked by blocking the breakdown of monoamine / indolamine nerve transmitters including dopamine, noradrenaline and serotonin by inhibiting an enzyme called MAO (monoamine oxidase). But when patients on these drugs ate cheese it could provoke periods of life-threateningly high blood pressure and a racing heart rate, through the uncontrolled release of adrenaline as there was no MAO to breakdown the tyramine in the diet.