2012 年 11 巻 3 号 p. 109-114
Tactile stimulation is an important factor in mother-infant interactions. Many studies on both human and animals have shown that tactile stimulation during the neonatal period has various beneficial effects in the subsequent growth of the body and brain. In particular, massage is often applied to preterm human babies as “touch care”, because tactile stimulation together with kinesthetic stimulation increases body weight, which is accompanied by behavioral development and the changes of endocrine and neural conditions. Among them, the elevation of insulin-like growth factor-1, catecholamine, and vagus nerve activity may underlie the body weight gain. Apart from the body weight gain, tactile stimulation has various effects on the nervous system and endocrine system. For example, it has been reported that tactile stimulation on human and animal babies activates parasympathetic nervous systems, while suppresses the hypothalamic-pituitary-adrenalcortical (HPA) axis, which may be related to the reduction of emotionality, anxiety-like behavior, and pain sensitivity. In addition, animal experiments have shown that tactile stimulation improves learning and memory. Facilitation of the neuronal activity and the morphological changes including the hippocampal synapse may underlie the improvement of the learning and memory. In conclusion, it has been strongly suggested that tactile stimulation in early life has beneficial effects on body, brain structure and function, which are maintained throughout life.