Subparaventricular zone
This is close to the SCN and input from this is integrated with other influences which modify circadian rhythms of sleep, temperature (via the VMPO), behaviour and endocrine control.

Dorsomedial nucleus
This receives fibres from the subparaventricular zone and inhibits the VLPO. It is particularly involved with temperature control and feeding behaviour, as well as arousal. It also projects to the paraventricular nucleus and the perifornical nuclei.

Basal forebrain (substantia innominata)
This lies just anterior to the preoptic area of the hypothalamus. It contains groups of neurones which have important influences on sleep.

Basal nucleus of Meynert
Its neurones are activated by glutamatergic neurones from the pons as well as the locus coeruleus, raphe nuclei and perifornical nuclei. They are cholinergic and are inhibited by accumulation of adenosine.

Neurones related to the amygdala, nucleus accumbens and ventral putamen
These are heterogeneous. Some are GABA-ergic neurones which are active particularly in stages 3 and 4 NREM sleep and project to the LDT/PPT. Others secrete glutamate or galanine as transmitters.