Department of Cellular and Molecular Pharmacology, The Chicago Medical School at Rosalind Franklin University of Medicine and Science, North Chicago, Illinois.
Department of Cellular and Molecular Pharmacology, The Chicago Medical School at Rosalind Franklin University of Medicine and Science, North Chicago, Illinois.
Biol Psychiatry. 2014 Mar 15;75(6):508-16. doi: 10.1016/j.biopsych.2013.07.033. Epub 2013 Sep 13.
Refinement of mature cognitive functions, such as working memory and decision making, typically takes place during adolescence. The acquisition of these functions is linked to the protracted development of the prefrontal cortex (PFC) and dopamine facilitation of glutamatergic transmission. However, the mechanisms that support these changes during adolescence remain elusive.
Electrophysiological recordings (in vitro and in vivo) combined with pharmacologic manipulations were employed to determine how N-methyl-D-aspartate transmission in the medial PFC changes during the adolescent transition to adulthood. The relative contribution of GluN2B transmission and its modulation by postsynaptic protein kinase A and D1 receptor signaling were determined in two distinct age groups of rats: postnatal day (P)25 to P40 and P50 to P80.
We found that only N-methyl-D-aspartate receptor transmission onto the apical dendrite of layer V pyramidal neurons undergoes late adolescent remodeling due to a functional emergence of GluN2B function after P40. Both protein kinase A and dopamine D1 receptor signaling are required for the functional expression of GluN2B transmission and to sustain PFC plasticity in response to ventral hippocampal, but not basolateral amygdala, inputs.
Thus, the late adolescent acquisition of GluN2B function provides a mechanism for dopamine D1-mediated regulation of PFC responses in an input-specific manner.
成熟认知功能(如工作记忆和决策制定)的细化通常发生在青春期。这些功能的获得与前额叶皮层(PFC)的长期发育以及多巴胺促进谷氨酸能传递有关。然而,支持青春期这些变化的机制仍然难以捉摸。
采用电生理记录(体外和体内)结合药理学操作,确定 N-甲基-D-天冬氨酸(NMDA)在 PFC 中的传递如何在青春期向成年期过渡期间发生变化。在两个不同的大鼠年龄组中确定了 GluN2B 传递的相对贡献及其被突触后蛋白激酶 A 和 D1 受体信号的调节:出生后第 25 天至第 40 天(P25-P40)和第 50 天至第 80 天(P50-P80)。
我们发现,只有 NMDA 受体传递到第 V 层锥体神经元的树突棘上发生了晚期青少年重塑,这是由于 P40 后 GluN2B 功能的功能性出现。蛋白激酶 A 和多巴胺 D1 受体信号都需要 GluN2B 传递的功能表达,并维持 PFC 对腹侧海马但不是基底外侧杏仁核输入的可塑性。
因此,晚期青少年 GluN2B 功能的获得为多巴胺 D1 介导的 PFC 反应调节提供了一种特定输入方式的机制。