Exposure to Young Triggers New Neuron Creation in Females Exhibiting Maternal Behavior
ScienceDaily (Dec. 27, 2009) — Maternal behavior itself can trigger the development of new neurons in the maternal brain independent of whether the female was pregnant or has nursed, according to a study released by researchers at Tufts University's Cummings School of Veterinary Medicine. These findings performed in adult, virgin rats were published in Brain Research Bulletin.
In the study, virgin, or nulliparous, rats were exposed to foster pups each day until they began to exhibit maternal behavior, including crouching over the young, grouping them, or retrieving them back to the nest. Data from the study showed that the nulliparous rats exposed to pups have increased numbers of new neurons.
The research was undertaken by Cummings School Department of Biomedical Sciences researchers Miyako Furuta and Robert Bridges, who is the head of the Cummings School's reproduction and neurobiology section.
Previous research has found that exposure to young can stimulate maternal behavior not only in rats, but also mice, hamsters, monkeys, and even humans. Increased creation of new neurons, or neurogenesis, has also been shown during pregnancy and lactation in rodents and associated with maternal behavior, but studies analyzing neurogenesis in nulliparous animals exhibiting maternal behavior had not been done. The area of the brain that was the focus of the present study was the subventricular region -- a region involved in the production of cells that affect odor recognition and possibly recognition of young. Bridges and Furuta found increased numbers of new neurons in the subventricular zone in adult, nulliparous rats that behaved maternally compared with numbers in subjects that either were not exposed to young or exposed to young, but did not behave maternally.
http://www.sciencedaily.com/releases/2009/12/091217115832.htm