M40

M40 is an antagonist or a weak agonist for galanin receptor depending on different subtypes of galanin receptors in the brain, hypothalamus, hippocampus, amygdala and pancreas^[1][2][3]. In Vitro:M40 (1 μM) displaces [mono[¹²⁵IJodo-Tyr²⁶]galanin from binding sites in the hippocampus, hypothalamus, and spinal cord. M40 has a lower affinity than galanin for all membranes. The IC₅₀ values are 6 nM in the hippocampus, 15 nM in the hypothalamus, 12 nM in the spinal cord, and 3 nM in the insulinoma cells. M40 (1 μM) completely blocks ¹²⁵I-labeled galanin-binding sites^[1]. In Vivo:M40 (0.1-1 nmol, intracisternal injection, single dose) blocks selectively the central cardiovascular responses induced by galanin-(1–15) in Sprague-Dawley rats models, according to the recognization of galanin receptor in N-terminus^[1].
M40 (2-8 nmol, intraventricular or intrahippocampal, single dose) exhibits antagonist efficacy against galanin on memory tasks in sprague-dawley rats models, exhibits potency in alleviating the cognitive deficits associated with Alzheimer's disease^[2].