Can Motherhood Sculpt the Brain?
Martin T. Stein, MD Reviewing Hoekzema E et al., Nat Neurosci 2016 Dec 19;
Functional imaging indicates that pregnancy elicits reductions in gray matter volume in human brain regions linked to maternal attachment.
Postpartum maternal behaviors cultivate mother-infant attachment to sustain a healthy emotional bond. In a prospective study, researchers measured gray matter volume with functional magnetic resonance imaging (fMRI) scans before conception and 2 months postpartum in 25 primiparous women. FMRI imaging before and after the pregnancy was also performed in the fathers as well as in a control group of 20 nulliparous women. In addition, fMRI images were generated in the mothers as they were shown pictures of their own or other infants. Maternal attachment was assessed with the Maternal Postnatal Attachment Scale. Comparison of preconception and postpartum brain images revealed reductions in gray matter volume after birth. These structural changes were localized to the anterior and posterior midline cortex and the prefrontal and temporal cortex, all brain regions associated with social cognition and the “theory-of-mind” network, a behavioral process that allows a person to think about how other people perceive things. Neither control women nor fathers showed gray matter volume reductions. Gray matter changes were significantly associated with quality of mother-infant attachment. The strongest neural activity in response to seeing pictures of the women's own baby corresponded to regions that lost gray matter volume during pregnancy. Scans performed 2 years after birth indicated that the gray matter volume reduction was sustained.
Despite limitations such as small sample size, this remarkable study is the first to correlate pregnancy with significant structural changes in human brain regions mediating early attachment. In a comment for The New York Times, neuroscientist Paul Thompson hypothesized that increased hormone levels during pregnancy may be associated with selective neuronal pruning or cellular adaptation. These findings raise several intriguing questions: For example, can absence of a healthy maternal-infant attachment be explained by failure of pregnancy-associated reductions in gray matter volume?
A child can go to school the day after diagnosis of ‘streptococcal throat’ if fever free and on oral antibiotics. If interested read further evidence in GP article this month.
Children treated with amoxicillin for strep throat may return to school the next day without putting other children at risk for contracting the illness, suggests a study published online August 20 in the Pediatric Infectious Disease Journal.
Current national and state public health recommendations stipulate that children should not return to school for at least 24 hours after testing positive for group A streptococci and beginning antibiotics. Yet a handful of small studies have found that positive cultures were unlikely as early as 18 hours after taking the antibiotic.
"In families where there are no stay-at-home parents the results of this study are meaningful," write Richard Schwartz, MD, from Inova Children's Hospital's Department of Pediatrics in Falls Church, Virginia, and colleagues. "If amoxicillin as a single dose is ingested by 5PM (at least 12 hours before arrival at school the following day), a return to school the next morning should be permitted by a modification of the state guidelines for return to school after diagnosis of strep throat." Such a policy change could lead to significant financial savings, improved school attendance, and reduced sick day usage by parents, the authors explain.
The researchers enrolled 111 children who had both a positive rapid strep test and a positive throat culture for group A streptococci when they visited a pediatric practice in Vienna, Virginia, between August 2013 and March 2015. Throat swab specimens were obtained and the children received an initial dose of amoxicillin 50 mg/kg/day. Between 12 and 23 hours after the first dose, all children returned for another throat swab, ear temperature reading, and oropharynx examination.
On the second day, 91% had undetectable group A streptococci on the rapid test, and on the throat culture (confidence interval [CI], 86% - 96%). There was no significant difference between those who had received a second antibiotic dose that morning (10% of 60 tested positive) compared with those who had not yet received their second dose (8% of 51 tested positive; P = .75).
The quantity of group A streptococci in throat cultures dropped from at least 50 beta-hemolytic colonies to fewer than 50 for all except two of the children (one with and one without a second dose), who tested positive the following morning.
"We conclude that all children treated with amoxicillin for streptococcal pharyngitis by 5 PM can, if afebrile and improved...be permitted to attend school on day 2," the authors write.Pediatric Infect Dis J. Published online August 20, 2015. Abstract