Baby's Nose Knows Mom's Smell
Infants Learn Mother's Scent, Say Researchers Studying Baby Rats
July 6, 2005 -- Babies learn their mother's smell early in life, wiring the
scent into their brains, new research shows.
That idea was tested on baby rats, not human infants. But the basic process
may be similar, say the researchers.
Smell is one way that newborn animals (including humans) forge strong ties
to their mothers, say researchers Kevin Franks, PhD, and Jeffry Isaacson,
Franks and Isaacson work in the neurosciences department of the medical
school of the University of California, San Diego (UCSD). Their findings appear
Smell often brings memories back to life.
"Get a whiff of chocolate chip cookies baking in the oven, and the smell
may conjure sudden fond memories of grandma's kitchen," says Benjamin
He didn't work on the study, but he wrote an editorial in Neuron
"Such strong odor associations are common, but we often take them for
granted," says Philpot.
"However, for a newborn infant trying to locate mother's nipple, the
association between odor and experience becomes a powerful force forming the
basis of a strong bond between infant and mother," he says.
The baby rats in the UCSD test were around their mothers a lot for feeding
and care. Each time, their tiny nostrils took in their mothers' scent.
The odor apparently became so familiar that the rats' brain cells started to
recognize it quickly. In essence, the scent became wired into their brains
through repeated exposure.
When one nostril was blocked, the lopsided odor exposure was reflected in
the rats' brain development. The brain receptors that pick up odor on the side
of the blocked nostril were developmentally delayed.
There may be a key time frame early in life when the development of nerve
pathways takes place, say the researchers.
The same pattern has been seen as babies' visual systems develop, they
A Dad's Perspective
Philpot wore two hats, so to speak, when he wrote his editorial.
He's an assistant professor of cell and molecular physiology at the
University of North Carolina at Chapel Hill. He's also a new dad.
Other simple but important factors could explain the observed brain changes,
But "as a neuroscientist and a new parent, I cannot help but to wonder
whether a synaptic trace is being left in my newborn daughter's olfactory
cortex every time she breastfeeds," he says.
In other words, his baby girl may be engraving her mother's scent in her
mind, making it one of her life's earliest discoveries.