Division of Brain and Neurophysiology, Department of Physiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi-ken, 329-0498, Japan.
Sci Rep. 2021 Feb 15;11(1):3805. doi: 10.1038/s41598-021-83314-w.
Gentle touch contributes to affiliative interactions. We investigated the effects of gentle stroking in female rats on the development of affiliative behaviors toward humans and we exploratively examined brain regions in which activity was influenced by stroking. Rats that had received stroking stimuli repeatedly after weaning emitted 50-kHz calls, an index of positive emotion, and showed affiliative behaviors toward the experimenter. Hypothalamic paraventricular oxytocin neurons were activated in the rats after stroking. The septohypothalamic nucleus (SHy) in the post-weaningly stroked rats showed decreased activity in response to stroking stimuli compared with that in the non-stroked control group. There were negative correlations of neural activity in hypothalamic regions including the SHy with the number of 50-kHz calls. These findings revealed that post-weaning stroking induces an affiliative relationship between female rats and humans, possibly via activation of oxytocin neurons and suppression of the activity of hypothalamic neurons.
轻抚有助于建立亲密关系。我们研究了对断奶后雌性大鼠进行轻抚对其与人类建立亲密关系行为发展的影响，并探索性地研究了受轻抚影响的大脑区域。接受反复轻抚刺激的大鼠在发出 50-kHz 叫声（一种积极情绪的指标）后，表现出对实验者的亲昵行为。在轻抚后，大鼠的下丘脑室旁核催产素神经元被激活。与未受刺激的对照组相比，在接受过轻抚的大鼠的隔下丘脑核 (SHy) 在对轻抚刺激的反应中表现出活性降低。包括 SHy 在内的下丘脑区域的神经活动与 50-kHz 叫声的数量呈负相关。这些发现表明，断奶后轻抚可诱导雌性大鼠与人类之间建立亲密关系，可能是通过激活催产素神经元和抑制下丘脑神经元的活动。
