NK3 receptor agonism promotes episodic-like memory in mice

The mammalian tachykinins are a family of closely related peptides including substance P, neurokinin A, neurokinin B and, recently, also hemokinin-1. They are present in the peripheral and central nervous systems, and bind to three known neurokinin (NK) receptors, the NK1-, NK2- and NK3 receptors. In both rodents and humans, NK3 receptors are expressed in brain structures which have been associated with learning and memory. Evidence for a role of NK3 receptors in learning and memory has been found in NK3 receptor knockout mice. Here, we investigated the influence of the NK3 receptor agonist, senktide (0.1, 0.2 and 0.4 mg/kg), on the performance of C57BL/6 mice in a recently developed episodic-like memory task. Since a promnestic effect of senktide was expected, we employed an experimental protocol that provided sub-optimal learning conditions for episodic-like memory. The results indicate that senktide promotes episodic-like memory in mice in a dose-dependent manner, providing, for the first time, evidence for an involvement of NK3 receptors in episodic-like memory.