A researcher at the University of British Columbia has discovered in her studies with rats, that first-time mothers experience enhanced learning abilities and memory performance. Her findings suggest that hormonal and cellular mechanisms underlying these changes may be similar to those found in humans.
“What we find in first-time mother rats during the late postpartum period when their pups are weaned, is improved learning and memory for tasks that rely on spatial cues,” says Jodi Pawluski, a Psychology PhD candidate specializing in Neuroscience.
Pawluski says compared to non-mothers or experienced mothers, these rats are much more able use to landmarks to navigate. “In fact, on some memory tasks first-time mothers show greater than 50 per cent improvement in performance compared to non-mothers.”
Pawluski studies how mothering experience significantly affects memory, hormones and the brain’s structure and function. She has compared first and multiple mothering experiences by observing, in animal models, the profound effect hormones have on the hippocampus, an area of the brain that plays a major role in mood and memory.
“Very few studies have investigated how pregnancy and motherhood affect the structural and functional properties of the hippocampus,” says Pawluski, who works with UBC Psychology Professor Dr. Liisa Galea.
Pawluski says along with heightened hormone levels, the brain also undergoes cellular changes. “We’re seeing significant changes in the neuron shape in first-time mothers.”
Numbering about 100 billion in humans, neurons are cells that send and receive electro-chemical signals to and from the brain and nervous system.
Pawluski says by understanding how cellular and hormonal changes can enhance memory during late postpartum, researchers can also hope to learn more about “maternal amnesia” or “baby brain.”
During late pregnancy and early postpartum, approximately 50 per cent of women report short-term memory loss, forgetfulness, disorientation, confusion, lack of concentration and reading difficulties.
“During pregnancy and mothering,” says Pawluski, “a woman’s body undergoes remarkable changes in the level of hormones such as estradiol, corticosterone, and progesterone, which impact many processes including mood, learning and memory.
“My research suggests the probable mechanism behind the enhanced learning and memory in first-time moms may be traced to the higher circulating levels of corticosterone, a hormone produced by the adrenal glands.”
Pawluski says these findings may also open new avenues of research that can lead to new therapies for postpartum depression and “baby blues,” hormonally-related mood swings that affect up to 90 per cent of women after giving birth.
Pawluski’s research is funded by the Natural Sciences and Engineering Research Council of Canada, the Canadian Institutes for Health Research and the Human Early Learning Partnership.
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