Serotonin, also called 5-hydroxytryptamine (5-HT), is a monoamine signaling molecule that functions throughout the entire body. The majority of serotonin is produced in the digestive tract and is important for normal gut function and sensation. In the mammalian central nervous system, serotonin production is restricted to neurons located in the raphe nuclei of the midbrain. These neurons have an extensive axonal network that innervate numerous targets both rostrally and caudally, allowing serotonin to influence a multitude of diverse behaviors and physiological functions. Serotonergic neurons in the rostral raphe nuclei innervate multiple cortical and subcortical structures, while axons from serotonergic neurons in the caudal raphe nuclei terminate in the brainstem and spinal cord. Serotonin has been shown to regulate sleep, circadian rhythms, appetite, mood, learning, memory, and neuroendocrine function. Low serotonin levels have been associated with a number of psychiatric disorders including depression, anxiety, bipolar disorder, obsessive-compulsive disorder, and addiction.
Tryptophan Hydroxylase 1 in Rat Brain.
Tryptophan Hydroxylase 1 (TPH 1) was detected in perfusion-fixed frozen sections of rat brain using a Goat Anti-Human Tryptophan Hydroxylase 1/TPH 1 Antigen Affinity-Purified Polyclonal Antibody (R&D Systems, Catalog # AF5276
). The tissue was stained using the NorthernLights™
557-Conjugated Donkey Anti-Goat IgG Secondary Antibody (R&D Systems, Catalog # NL001
; red) and counterstained with DAPI (blue). Specific staining was localized to neuronal processes.