Intrahippocampal glucocorticoids generated by 11β-HSD1 affect memory in aged mice

Area of Science:

• Neuroscience
• Endocrinology
• Aging Research

Background:

• 11-beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) reactivates glucocorticoids in tissues.
• Hippocampal 11β-HSD1 mRNA expression increases with age.

Purpose of the Study:

• To investigate the role of hippocampal 11β-HSD1 in age- and stress-related spatial memory deficits.
• To determine if 11β-HSD1 inhibition can ameliorate these impairments.

Main Methods:

• Comparison of spatial memory and hippocampal corticosterone (CORT) levels in aged wild-type (WT) and 11β-HSD1 knockout (KO) mice.
• Assessment of stress effects on spatial memory and CORT in young WT mice.
• Evaluation of pharmacologic 11β-HSD1 inhibition in aged WT mice.

Main Results:

• Aged WT mice showed higher hippocampal CORT and impaired spatial memory compared to aged 11β-HSD1 KO mice.
• Acute stress increased hippocampal CORT and impaired memory in young WT mice, an effect absent in 11β-HSD1 KO mice.
• Pharmacologic inhibition of 11β-HSD1 prevented memory impairment in aged WT mice.

Conclusions:

• Increased hippocampal 11β-HSD1 activity contributes to spatial memory impairment in aging and stress.
• Targeting 11β-HSD1 offers a potential therapeutic strategy for cognitive decline associated with aging and stress.