The effect of a modified fragment of neuropeptide y on spatial memory and learning in the Morris water maze

Abstract

Neuropeptide Y (NPY) is a biologically active neuropeptide that is responsible for a large list of physiological processes. We propose a short modified fragment of NPY that should at least partially have a spectrum of biological activity of the original peptide. The compound was named nonapeptide NP9. The aim of our study was to investigate the ability of the modified fragment of NPY to influence spatial memory and learning. Materials and methods: the study was performed on 24 one-year-old random-bred female rats weight 220–250 g. The animals were divided into 3 groups of 8 rats each: treated with a solvent (0.9 % NaCl), a solution of peptide NP9 0.02 mg/kg and the drug “Semax” 0.1 mg/kg. All drugs were administered intranasally. The study of the effect of the peptide NP9 on spatial memory and learning ability was performed in the psychopharmacological test the Morris water maze. Navigation parameters were analyzed using Noldus EthoVision XT 14 video tracking software. The escape latency, the distance moved, the average velocity and the meander were recorded. An inter-quadrant analysis of rat behavior was also performed, for which the frequency of appearance and time spent in certain quadrants were recorded. Results: nonapeptide NP9 in the Morris water maze test demonstrated the ability to accelerate the time to find a hidden platform, reduce the distance traveled, meander, and optimize the search strategy. Conclusions: NP9 peptide has demonstrated the ability to positively influence learning and spatial memory. The improvement in cognitive performance of animals administered with the peptide NP9 was no less than that of the reference nootropic drug Semax. These results substantiate the feasibility of further research with the aim of pharmaceutical development of a new nootropic drug