A new tool for measuring the suckling stimulus during breastfeeding in humans: the orokinetogram and the Fourier series.

The Fourier series was used to analyse the oral movements recorded by the orokinetogram during breastfeeding in human babies. This is a new method that allows recording of oral movements without introducing any extrinsic element between the nipple and the mouth of the baby. The advantage of displaying suckling activity after fast Fourier transform (FFT) is that this algorithm allows storage, quantification and frequency analysis of the oral movements throughout a suckling bout, which enables the total oral activity to be measured.

Suckling-induced serum prolactin levels are modified by interference with milk ejection in lactating rats.

The aim of this study was to determine whether suckling-induced prolactin (PRL) levels were modified when milk ejection was impaired. Milk ejection impairment was achieved in two experimental models: a) depriving the dam of sleep during suckling and b) increasing the nonsuckling intervals in lactating dams. Sleep deprivation blocked milk ejection and enhanced suckling-induced PRL levels in dams that had been previously separated from their pups.

Electronmicroscopic and electrophysiological studies of the teat branch of the XIII thoracic nerve: relationship with lactation in the rat.

Electrical stimulation of the XIII thoracic nerve (the 'mammary nerve') causes milk ejection and the release of prolactin and other hormones. We have analysed the route of the suckling stimulus at the level of different subgroups of fibres of the teat branch of the XIII thoracic nerve (TBTN), which innervates the nipple and surrounding skin, and assessed the micromorphology of the TBTN in relation to lactation. There were 844 +/- 63 and 868 +/- 141 (S.

Relationship of prolactin release in lactating rats to milk ejection, sleep state, and ultrasonic vocalization by the pups.

PRL release, milk ejection, and electroencephalographic states of sleep were monitored in conscious, lactating Holtzman rats. Plasma PRL levels were low in rats separated from their litters, but they increased when pups were returned to the cage, attached to the nipples of the mother, and suckled. The pups emitted ultrasonic vocalizations upon their return to the cage and before their attachment to the nipples.