Locomotion and respiration in human infants

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Centres in the nervous system that control walking are coordinated with centres that control breathing and heart rate. When we start to walk or run, our breathing and heart rate quicken, in anticipation of the new demand.  These changes are very fast, essentially simultaneous with the movement.  In certain situations such as jogging, our breathing becomes exactly synchronized with our running movements.  We will determine if the same occurs in young babies under the age of 1 year.  Babies will be studied in the lab.  They will be supported to step on a treadmill as we have done in the past.  We will record their movement with video, and force plates under the treadmill belt.  Breathing will be monitored with a small thermocouple, and electrocardiogram will record the heart rate.  In study 1, the transition from stationary sitting/standing to walking and back to stationary conditions will be studied.  We anticipate the rate of breathing will change immediately at the start of movement, and the change will be dependent on the speed of walking.  In study 2, we will determine if breathing is exactly synchronized with movement under certain situations.  Because some believe the coordination is dependent on the mechanical demands of the task, we will study babies kicking, jumping, creeping and crawling.  These tasks were chosen to represent a variety of mechanical constraints.  In study 3, we will determine if practice in a particular activity enhances the coordination between breathing and limb movements in babies.  Jumping will be used, because pilot data indicate breathing and jumping tend to be synchronized.  These sets of experiments will break new ground in our understanding of how pattern generators relate to each other in the very young human.  At present, nothing is known about how these nerve centres relate to each other in the young.  If breathing is indeed coordinated with limb movements, in the future, we may be able to use one type of rhythm to alter or stabilize another rhythm.  For example, if the breathing rhythm is irregular, can it be altered by rhythmic limb movements?