Deleting a gene works up smarter brain

A genetic deletion helps work up a smarter brain by not only growing more brain cells during ageing but also making anti-depressants more effective in lower doses, a study reveals. Deleting the Nf1 gene in mice improves neurogenesis (the process by which brain cells are generated), which in turn makes those in the test group more sensitive to the effects of anti-depressants. "The significant implication of this work is that enhancing neurogenesis sensitises mice to anti-depressants — meaning they needed lower doses of the drugs to affect 'mood,'" said Luis Parada, from the University of Texas Southwestern Medical Centre. It also appears to have anti-depressive and anti-anxiety effects of its own that continue over time, added Parada, Director of the Kent Waldrep Centre for Basic Research on Nerve Growth and Regeneration and senior study author, The Journal of Neuroscience reported. Just as in people, mice produce new neurons throughout adulthood, although the rate declines with age and stress, said Parada, according to a university statement. Studies have shown that learning, exercise, shock therapy and some anti-depressants can increase neurogenesis. The steps in the process are well known but the cellular mechanisms behind those steps are not. The researchers used a sophisticated process to delete the gene that codes for the Nf1 protein only in the brains of mice, while production in other tissues continued normally. Researchers found that the test group mice formed more neurons over time compared to others, and that young mice lacking the Nf1 protein required much lower amounts of anti-depressants to counteract stress.