Blockade of central 5HT6 receptors has been shown to increase glutamatergic and cholinergic neurotransmission in various brain areas,[11][12][13][14] whereas activation enhances GABAergic signaling in a widespread manner.[15] Antagonism of 5HT6 receptors also facilitates dopamine and norepinephrine release in the frontal cortex,[14][16] while stimulation has the opposite effect.[15]
As a drug target for antagonists
Despite the 5HT6 receptor having a functionally excitatory action, it is largely co-localized with GABAergic neurons and therefore produces an overall inhibition of brain activity.[15] In parallel with this, 5HT6 antagonists are hypothesized to improve cognition, learning, and memory.[17] Agents such as latrepirdine, idalopirdine (Lu AE58054), and intepirdine (SB-742,457/RVT-101) were evaluated as novel treatments for Alzheimer's disease and other forms of dementia.[14][18][19] However, phase III trials of latrepirdine, idalopirdine, and intepirdine have failed to demonstrate efficacy.
5HT6 antagonists have also been shown to reduce appetite and produce weight loss, and as a result, PRX-07034, BVT-5,182, and BVT-74,316 are being investigated for the treatment of obesity.[20][21]
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