Efficient learning in children with rapid GABA boosting during and after training.

It is generally thought that children learn more efficiently than adults. One way to accomplish this is to have learning rapidly stabilized such that it is not interfered with by subsequent learning. Although γ-aminobutyric acid (GABA) plays an important role in stabilization, it has been reported that GABAergic inhibitory processing is not fully matured yet in children compared with adults. Does this finding indicate that more efficient learning in children is not due to more rapid stabilization? Here, we measured the concentration of GABA in early visual cortical areas in a time-resolved fashion before, during, and after visual perceptual learning (VPL) within subjects using functional MRS (fMRS) and then compared the concentrations between children (8 to 11 years old) and adults (18 to 35 years old). We found that children exhibited a rapid boost of GABA during visual training that persisted after training ended, whereas the concentration of GABA in adults remained unchanged. Moreover, behavioral experiments showed that children exhibited rapid development of resilience to retrograde interference, which indicates that children stabilize VPL much faster than adults. These results together suggest that inhibitory processing in children's brains is more dynamic and adapts more quickly to stabilize learning than in adults, making learning more efficient in children.

Fusobacterium necrophorum bacteremic tonsillitis: 2 Cases and a review of the literature.

Fusobacterium necrophorum can cause endemic pharyngitis and the Lemierre syndrome. Four previous case reports and one epidemiologic study have documented that some F. necrophorum pharyngitis patients develop bacteremia without developing the complete Lemierre syndrome. We report two more patients who have bacteremic F. necrophorum pharyngitis. We summarize the clinical presentation of these six patients. All received early diagnosis and excellent response to antibiotics. We speculate that prompt antibiotic treatment may have prevented the more serious Lemierre syndrome. Adolescents and young adults who present with significant pharyngotonsillitis and bacteremic symptoms should have blood cultures and receive antibiotic regimens that treat F. necrophorum. Recognition of such patients might prevent Lemierre syndrome.