carbocyanines and Memory-Disorders

The aim of this study is to evaluate the effects of NK-4, a kind of cyanine dye, on cholinergic memory deficits in mice. We examined whether NK-4 could reverse scopolamine-induced amnesia in mice since NK-4 displays a potent and selective inhibitory effect on acetylcholinesterase (AChE) in vitro. Intraperitoneal administration of NK-4 significantly reversed scopolamine-induced cognitive impairments in mice in the Y maze and the passive avoidance tests, and NK-4 also improved spatial learning ability in the Morris water maze test. Despite NK-4 displaying remarkable AChE inhibitory activity in vitro, we could not detect a significant reduction of AChE activity in brain homogenates of NK-4-treated mice. Although the mechanism through which NK-4 reverses cognitive impairments in scopolamine-treated mice remains unclear, these data suggest that NK-4 may have potential as a therapeutic agent for the treatment of dementia.

Topics: Acetylcholinesterase; Animals; Avoidance Learning; Behavior, Animal; Butyrylcholinesterase; Carbocyanines; Cerebral Cortex; Hippocampus; Male; Maze Learning; Memory Disorders; Mice; Mice, Inbred ICR; Motor Activity; Neuroprotective Agents; Rats; Rats, Inbred F344; Scopolamine