Characterization of the developmental stages of sucking in preterm infants during bottle feeding.

It is acknowledged that the difficulty many preterm infants have in feeding orally results from their immature sucking skills. However, little is known regarding the development of sucking in these infants. The aim of this study was to demonstrate that the bottle-feeding performance of preterm infants is positively correlated with the developmental stage of their sucking.

MK-801 blocks the development of sensitization to the locomotor effects of methylphenidate.

Male Sprague-Dawley rats were divided to three groups (each n = 8) and were housed in test cages where motor activity was recorded continuously for 16 days using a computerized motor activity monitoring system to determine whether repeated administration of MK-801 could block the development and/or the expression of sensitization to the locomotor effects of methylphenidate (MPD). One group of rats received six daily injections (days 4-9) of 0.30 mg/kg MK-801, followed by 5 days without injection (days 10-14) and re-challenged (day 15) with 0.