调查称，美国26％的中小学生在进入青春期之后学习成绩出现下降。3月19日的《科学》Science杂志报道说。这并非玩笑：当青春期来临时，人们实际上学习能力也会下降。 这一学习能力下降的阶段已有充分的证明，但现在，研究人员已经在小鼠中找到了在这些青春发动期动物体内的可减缓学习过程的某些细胞学和分子学的基础。
美国纽约州立大学Hui Shen及其同僚结合高倍显微镜、药理学、生理学及行为测试等手段发现了某些受体复合物，这些复合物在青春期的时候会出现在脊髓的突触周围，从而影响海马体的功能并降低学习的能力。
这些特殊的GABAA 和 GABAR受体会在小鼠的青春期出现，并干扰输送到海马体的信号，而这些信号对神经元之间的交流是至关重要的。 因此，这些年轻的小鼠在实验室的测试中会出现空间学习能力下降的迹象。 研究人员还发现，一种特别的应激类固醇THP（它在正常时的作用是损害老年人的学习能力）实际上能够逆转这一青春期所驱动的学习能力下降的缺陷。研究人员提示，该应激类固醇可用来改变在青春期功能减缓的神经元的功能。 (生物谷Bioon.com)
APAM：超重男孩青春期可能迟到
PNAS：酒精使青春期变得更加疯狂
Nature Immunology：让精疲力竭的免疫细胞恢复青春
生物谷推荐原文出处：
Science DOI: 10.1126/science.1184245
A Critical Role for Alpha4-Beta-Delta GABAA Receptors in Shaping Learning Deficits at Puberty in Mice
Hui Shen,1,* Nicole Sabaliauskas,1,2,* Ang Sherpa,1,3 André A. Fenton,1,3,4 Armin Stelzer,1,3,4 Chiye Aoki,2 Sheryl S. Smith1,3,4,
The onset of puberty defines a developmental stage when some learning processes are diminished, but the mechanism for this deficit remains unknown. We found that, at puberty, expression of inhibitory 4β -aminobutyric acid type A (GABAA) receptors (GABAR) increases perisynaptic to excitatory synapses in CA1 hippocampus. Shunting inhibition via these receptors reduced N-methyl- D-aspartate receptor activation, impairing induction of long-term potentiation (LTP). Pubertal mice also failed to learn a hippocampal, LTP-dependent spatial task that was easily acquired by –/– mice. However, the stress steroid THP (3OH-5[β]-pregnan-20-one), which reduces tonic inhibition at puberty, facilitated learning. Thus, the emergence of 4β GABARs at puberty impairs learning, an effect that can be reversed by a stress steroid.
1 Department of Physiology and Pharmacology, State University of New York (SUNY) Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.
2 Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
3 Program in Neural and Behavioral Science, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.
4 The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.
