a Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology , Semmelweis University , Budapest , Hungary.
b MTA-SOTE NAP_A Human Brain Tissue Bank and Laboratory, Semmelweis University and the Hungarian Academy of Sciences , Budapest , Hungary.
Nutr Neurosci. 2018 Jun;21(5):317-327. doi: 10.1080/1028415X.2017.1286446. Epub 2017 Feb 10.
The aim of the study was to understand the effects of suckling on the brain of the pups by mapping their brain activation pattern in response to suckling.
The c-fos method was applied to identify activated neurons. Fasted rat pups were returned to their mothers for suckling and sacrificed 2 hours later for Fos immunohistochemistry. Double labeling was also performed to characterize some of the activated neurons. For comparison, another group of fasted pups were given dry food before Fos mapping.
After suckling, we found an increase in the number of Fos-immunoreactive neurons in the insular and somatosensory cortices, central amygdaloid nucleus (CAm), paraventricular (PVN) and supraoptic hypothalamic nuclei, lateral parabrachial nucleus (LPB), nucleus of the solitary tract (NTS), and the area postrema. Double labeling experiments demonstrated the activation of calcitonin gene-related peptide-ir (CGRP-ir) neurons in the LPB, corticotropin-releasing hormone-ir (CRH-ir) but not oxytocin-ir neurons in the PVN, and noradrenergic neurons in the NTS. In the CAm, Fos-ir neurons did not contain CRH but were apposed to CGRP-ir fiber terminals. Refeeding with dry food-induced Fos activation in all brain areas activated by suckling. The degree of activation was higher following dry food consumption than suckling in the insular cortex, and lower in the supraoptic nucleus and the NTS. Furthermore, the accumbens, arcuate, and dorsomedial hypothalamic nuclei, and the lateral hypothalamic area, which were not activated by suckling, showed activation by dry food.
Neurons in a number of brain areas are activated during suckling, and may participate in the signaling of satiety, taste perception, reward, food, and salt balance regulation.
本研究旨在通过绘制幼鼠吸吮时的大脑激活模式，了解吸吮对幼鼠大脑的影响。
应用 c-fos 方法识别激活神经元。将禁食的幼鼠送回母亲处吸吮，并在 2 小时后进行 Fos 免疫组织化学检测。还进行了双重标记以鉴定一些激活的神经元。为了比较，另一组禁食的幼鼠在进行 Fos 映射之前给予干食。
吸吮后，我们发现岛叶和体感皮质、杏仁中央核（CAm）、室旁核（PVN）和视上核、外侧臂旁核（LPB）、孤束核（NTS）和最后区的 Fos 免疫反应性神经元数量增加。双重标记实验表明，LPB 中的降钙素基因相关肽-ir（CGRP-ir）神经元被激活，PVN 中的促肾上腺皮质激素释放激素-ir（CRH-ir）但不是催产素-ir 神经元被激活，NTS 中的去甲肾上腺素能神经元被激活。在 CAm 中，Fos-ir 神经元不含有 CRH，但与 CGRP-ir 纤维末端相邻。用干食再喂养会导致所有被吸吮激活的脑区的 Fos 激活。与吸吮相比，干食在岛叶中引起的激活程度更高，而在视上核和 NTS 中则较低。此外，弓状核、腹内侧下丘脑核和外侧下丘脑区等未被吸吮激活的脑区也被干食激活。
吸吮过程中，许多脑区的神经元被激活，可能参与饱腹感、味觉感知、奖励、食物和盐平衡调节的信号传递。
