Reversal of lipopolysaccharide-induced learning and memory deficits by agmatine in mice

Abstract

Purpose/Aim: Infection and inflammation are important pathological mechanism underlying neurodegenerative disorders and altered behavioral outcomes including learning and memory. The present study was designed to study the curative and preventive effects of agmatine in lipopolysaccharide (LPS)-induced learning and memory impairment in mice.

Materials and methods

Learning and memory functions in animals were evaluated by using Novel object recognition (NOR) and Morris water maze (MWM) tests. Following 7 days of LPS administration, animals were subjected to NOR test on Day-8 and MWM test on Days-9 to 13 for the assessment of recognition and spatial learning and memory, respectively.

Results

LPS administration produced significant deficits in recognition and spatial memory in mice after seven days of LPS administration. In LPS pre-treated mice, agmatine treatment on Day-8 resulted in the increased exploration to the novel object. Agmatine treatment (Day 8-12) in mice showed reduction in the escape latency and time spent in the target quadrant (probe trial) in the MWM test. However, co-administration of agmatine with LPS in mice for 7 days showed higher discrimination index in NOR test on Day-8. This co-administration also decreased escape latency and time spent in the target quadrant in MWM test on Days 9-13 as compared to LPS control group.

Conclusion

Results implies the protective and curative effects of agmatine against LPS-induced loss of memory functions in experimental animals.

Highlights

1. Subchronic but not acute lipopolysaccharides induce memory deficits

2. Lipopolysaccharides impairs recognition and spatial memory in mice.

3. Agmatine prevents lipopolysaccharides-induced loss of memory.

4. Agmatine reverses deficits in learning and memory by lipopolysaccharides.

Keywords:

• Learning and memory
• lipopolysaccharide
• Morris water maze
• neuroinflammation
• novel object recognition test

Acknowledgement

We acknowledge the help of Ashish Bharne, Ph.D. for the statistical analysis and result compilation.

Disclosure statement

No potential conflict of interest was reported by the author(s).