Experiments using zebrafish identify a novel sleep-promoting neuronal circuit in which hypothalamic NPVF neurons promote sleep via the hindbrain serotonergic raphe nuclei, which promote sleep in both zebrafish and mice.

Dopaminergic and serotonergic neurons in the dorsal raphe nucleus have distinct electrical and morphological properties, which are differentially altered following dopamine and noradrenaline depletion.

The dorsal raphe nucleus contains transcriptionally diverse cell classes that include subtypes of serotonergic neurons with distinct molecular and anatomical signatures.

Kinetic interactions between sodium channels and auxiliary factors create a molecular computational engine that can sense and regulate cellular excitability.

Serotonin-releasing neurons show tonic firing-rate changes correlating with global reward value in addition to phasic firing-rate changes correlating with local task events.

Dorsal raphe Pet1 neurons are molecularly heterogeneous, comprising as many as fourteen distinct subtypes that show biased cell body distributions across dorsal raphe subdomains.

Neurexins are presynaptic adhesion molecules in the serotonin system which regulate neuron survival and serotonin neuromodulation through active zone formation and serotonin release.

Serotonergic input to visual cortex controls ongoing and evoked activity in a separable manner via distinct receptor pathways.

The collective action of six transcription factors selects and activates the regulatory regions of the HSN serotonergic neuron effector genes constituting a signature that can be used for the novo identification of HSN expressed genes.

Serotonin neurons in chronically isolated mice become less responsive to excitatory stimulation, but inhibiting a distinctive calcium-activated potassium channel can restore both neuronal activity and behavior.