"Nampt knockdown recapitulates hippocampal cognitive phenotypes in old mice which nicotinamide mononucleotide improves"In our present study, we found that older mice developed a cognitive hypersensitivity following exposure to certain aversive environmental stimuli, possibly reflecting age-related alterations in emotionality (fear and/or anxiety) and sensory processing.
Interestingly, NMN supplementation to old mice was able to mitigate age-associated cognitive hypersensitivity and age-associated increases in shock sensitivity, raising the possibility that modifications in the NMN supplementation procedure (e.g., extended treatment duration) might lead to greater positive effects concerning the putative emotionality component of the age-related hypersensitivity as well.
In conclusion, our study demonstrates that age-associated alteration in cognitive and behavioral functions is induced by reduced NAMPT-mediated NAD+ biosynthesis in the hippocampus, particularly in the CA1 region, in old mice.
Our study also shows that NMN supplementation, even in the short term, is able to mitigate the age-associated alteration in the sensory processing of some aversive stimuli and possibly other related behaviors.
Although further detailed analyses will be necessary, our findings provide critical insights into how aging affects cognitive and behavioral functions and how such impairments can be prevented or treated to enhance the quality of our later lives.