Abstract
Purpose:
The present studies demonstrate that environmental enrichment increases neural factors in various organs including the brain. We investigated the effects of environmental enrichment on tear secretion in mice.
Methods:
Male C57BL/6JJcl mice were exposed to an enriched environment (n=6) compared to mice living in a standard environment (n=6) for 4 weeks. After 4 weeks, we restrained the mice once as an acute stress test for 4 hours. Tear secretion was measured by using cotton threads (Zone Quick) for 30 seconds at once a week, pre- and post-acute stress. Body weight was also measured at the same point in time.
Results:
The tear secretion in the enriched environment (EE) group was significantly higher (2.5±0.5mm) than in the standard environment (ST) group (1.7±0.5mm)(p<0.05) at 1 week. Also the body weight in the EE group was significantly larger (21.4±0.6g, 22.4±0.6g) than in ST group (20.3±1.0g, 21.5±0.8g)(p<0.05) at 2 weeks and 3 weeks. After the acute stress test, tear secretion was on a downward trend in only the ST group. The body weight significantly decreased in both EE and ST groups. But this tendency was remarkable in ST group (p<0.01) compared to the EE group (p<0.05).
Conclusions:
The results of this study suggest that environmental enrichment may weaken deleterious effects by an acute stress on the body in mice.
Keywords: 576 lacrimal gland •
726 stress response