The influence of tactile stimulation of nipples on the milk ejection reflex in the rat

✍ Scribed by M. G. Karyakin; N. P. Alekseev

• Publisher: Springer
• Year: 1992
• Tongue: English
• Weight: 580 KB
• Volume: 170
• Category: Article
• ISSN: 0340-7594
• DOI: 10.1007/bf00199340

✦ Synopsis

Changes of positive pressure exerted by pups on nipples during sucking were investigated using anesthetized, lactating dams. It was found that, every 50-60 s, individual pups performed bouts of pressure oscillations (3/s) of high amplitude which lasted about 10-12 s and coincided with periods of increased motor activity. During the intervals, when pups were quiet, series of low-amplitude oscillations (3/s) were also observed. Using a strain measuring method to record the activity of sucking pups, synchronization of activity of two or more pups was found to occur periodically every 25-30 s and, most frequently, 10-30 s before the reflex increase of milk pressure. In further experiments, artificial tactile stimulation was applied to the dam's nipples using the joint action of suction and positive pressure. Following a short-term (10-20 s) increase in frequency and amplitude of artificial nipple stimulation, 60%-80% of all reflexive peaks of milk pressure were elicited with a latency of 19 +__ 5 s. This suggests that there are specific conditions under which the stimulation of nipples by pups may trigger the formation of the milk ejection reflex in the rat.