What is Tachykinin?

Tachykinins are a family of related neuropeptides, which are brain chemicals comprised of short protein sequences encoded directly by specific genes. These neuropeptides are distinct from simpler organic molecule neurotransmitters like dopamine and serotonin. In the brain, tachykinins are released alongside classical neurotransmitters such as glutamate when certain neurons are activated.

Tachykinins play various roles across different species, including managing pain, modulating aggression, and influencing behaviors related to social isolation. For example, Substance P, a kind of tachykinin, is involved in modulating inflammatory pain. In terms of behavior, experiments have shown that activating certain tachykinin-related neurons in flies can promote aggression, a trait that increases with social isolation in these creatures as well as in other species, including humans.

Moreover, tachykinins are involved in the neural circuits related to stress and trauma. The upregulation of tachykinins can increase feelings of anxiety and aggression, which are further amplified by social isolation. Interestingly, social connections, which might reduce the effectiveness or levels of tachykinins, play a therapeutic role in mitigating these negative effects 1 2.