In the absence of any overt task performance, it has been shown that spontaneous, intrinsic brain activity is expressed as systemwide, resting-state networks in the adult brain. However, the route to adult patterns of resting-state activity through neuronal development in the human brain is currently unknown. Therefore, we used functional MRI to map patterns of resting-state activity in infants during sleep. We found five unique resting-states networks in the infant brain that encompassed the primary visual cortex, bilateral sensorimotor areas, bilateral auditory cortex, a network including the precuneus area, lateral parietal cortex, and the cerebellum as well as an anterior network that incorporated the medial and dorsolateral prefrontal cortex. These results suggest that resting-state networks driven by spontaneous signal fluctuations are present already in the infant brain. The potential link between the emergence of behavior and patterns of resting-state activity in the infant brain is discussed.development ͉ functional MRI ͉ spontaneous activity R ecent research on functional connectivity in the brain, in particular during resting-state conditions, has come to focus on low-frequency (Ͻ0.1 Hz), spontaneous fluctuations in the functional MRI (fMRI) signal. Discovered by Biswal et al. (1), it has been shown that systemwide networks in the resting brain are synchronized in time through intrinsic low-frequency signal fluctuations. Whereas early fMRI studies demonstrated synchronicity of intrinsic brain activity across hemispheres in primary sensory cortices (2, 3), succeeding studies have shown temporal synchronization in a resting-state network encompassing higher-order cortices (4). A systematic investigation of resting-state activity in the adult human brain was recently presented by Damoiseaux et al. (5). Using independentcomponent analysis (ICA), a data-driven explorative data analysis approach, they showed that there are numerous networks in the brain that are driven by spontaneous activity. Besides networks that are in part or fully described by the previously reported default mode (6) and task-positive network (7, 8), they found consistent patterns of resting-state activity in the visual cortex, sensorimotor areas, auditory areas, as well as extrastriate brain regions. These findings together with previous investigations on spontaneous activity suggest that the assumption that the brain during rest is idle and waiting to be triggered and respond to changes in the environment is not strictly valid. Rather, in addition to responding to changes in external stimuli or tasks, the brain is characterized by intrinsic dynamics in the form of coherent and spontaneous fluctuations, clustered together in networks that are credible from an anatomical and functional perspective.Interestingly, recent studies have presented evidence that spontaneous activity is relevant for human behavior. Momentary lapses of attention, affecting goal-oriented behavior on a global/ local selective attention task, were related to a fai...

PROACTIVE APPROACH TO resuscitation and intensive care of extremely preterm infants (Ͻ27 gestational weeks) has increased survival and lowered the gestational age of viability. 1-4 There are concerns that increased survival may come at the cost of later neurodevelopmental disability among survivors. Approximately 25% of extremely preterm infants born in the 1990s had a major disability at preschool age, such as impaired mental development, cerebral palsy (CP), blindness, or deafness. 5,6 More recent studies report decreasing, 7,8 unchanged, 2 or increasing rates of neurodevelopmental disability 9-11 at preschool age compared with previous decades. The most immature infants, ie, those born before 25 weeks Author Affiliations and Members of the EXPRESS Group appear at the end of this article.

The functional network topology of the adult human brain has recently begun to be noninvasively mapped using resting-state functional connectivity magnetic resonance imaging and described using mathematical tools originating from graph theory. Previous studies have revealed the existence of disproportionally connected brain regions, so called cortical hubs, which act as information convergence zones and supposedly capture key aspects of how the brain's architecture supports human behavior and how it is affected by disease. In this study, we present results showing that cortical hubs and their associated cortical networks are largely confined to primary sensory and motor brain regions in the infant brain. Our findings in infants stand in stark contrast to the situation found in adults where the majority of cortical hubs and hub-related networks are located in heteromodal association cortex. Our findings suggest that the functional network architecture in infants is linked to support tasks that are of a perception-action nature.

The effect of hypoxia-ischemia (HI) on IL-1, and IL-6 bioactivity in relation to expression of IL-1 alpha, IL-1 beta, and IL-6 mRNA was studied, and the neuroprotective efficacy of IL-1 receptor antagonist (IL-1ra) was evaluated in neonatal rats. HI was induced in 7-d-old rats by unilateral carotid artery ligation and hypoxia for 70-100 min. Animals were killed at different time points up to 14 d after HI, and brains were analyzed for IL-1 and IL-6 bioactivity using bioassays and for mRNA for IL-1 alpha, IL-1 beta, and IL-6 with reverse transcription followed by a polymerase chain reaction. In separate animals, IL-1ra was administered intracerebrally before or after HI, and the extent of brain injury was assessed 14 d after HI. A transient increase of IL-1 bioactivity occurred after HI, reaching a peak at 6 h of recovery. IL-1 beta mRNA followed a similar time course but attained maximum expression at 3 h. IL-6 bioactivity and mRNA were also stimulated by HI and followed a similar time course as IL-1. Pretreatment with IL-1ra reduced HI brain damage from 54.4 +/- 9.3 to 41.4 +/- 10.0% (p < or = 0.01), and IL-1ra posttreatment increased the proportion of animals devoid of brain injury (40%) compared with vehicle-treated controls (13%) (p < or = 0.05). In conclusion, a transient activation of IL-1 and IL-6 occurred after HI, and IL-1ra reduced HI brain injury to a moderate degree.

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