Ottawa, May 26 (IANS): Looking at the effects of hormone therapy on females, researchers have found that pregnancy and motherhood could stimulate certain permanent changes in the brain.

Hormone therapy (HT) is prescribed to alleviate some of the symptoms of menopause in women.

"Our most recent research shows that previous motherhood alters cognition and neuroplasticity in response to hormone therapy, demonstrating that motherhood permanently alters the brain," said researcher Liisa Galea from University of British Columbia in Canada.

The study focused on a specific brain region, called the hippocampus, which has important roles in memory and spatial ability, such as navigational skills.

The researchers investigated whether the different forms of the hormone estrogens could have different effects on rats that had experienced motherhood once and on those who had not.

There are three forms of estrogens: estradiol, estrone and estriol.

They found that estrone-based HT improved learning in middle-aged rats who had not experienced motherhood, but impaired learning in rats of the same age who experience motherhood.

"Hormones have a profound impact on our mind. Pregnancy and motherhood are life-changing events resulting in marked alterations in the psychology and physiology of a woman," Galea said.

"Our results argue that these factors should be taken into account when treating brain disorders in women," she said.

The findings were presented at ninth Annual Canadian Neuroscience Meeting in Vancouver, British Columbia.