Inserm, Marseille, France.
Aix-Marseille University, UMR, Marseille, France.
Cereb Cortex. 2019 Jun 1;29(6):2639-2652. doi: 10.1093/cercor/bhy132.
The dentate gyrus, the entry gate to the hippocampus, comprises 3 types of glutamatergic cells, the granule, the mossy and the semilunar granule cells. Whereas accumulating evidence indicates that specification of subclasses of neocortical neurons starts at the time of their final mitotic divisions, when cellular diversity is specified in the Dentate Gyrus remains largely unknown. Here we show that semilunar cells, like mossy cells, originate from the earliest stages of developmental neurogenesis and that early born neurons form age-matched circuits with each other. Besides morphology, adult semilunar cells display characteristic electrophysiological features that differ from most neurons but are shared among early born granule cells. Therefore, an early birthdate specifies adult granule cell physiology and connectivity whereas additional factors may combine to produce morphological identity.
齿状回是海马的入口，它包含 3 种谷氨酸能细胞，即颗粒细胞、苔藓细胞和半月形颗粒细胞。越来越多的证据表明，新皮层神经元亚类的特化始于其最后有丝分裂分裂的时期，而齿状回中细胞多样性的特化在很大程度上仍然未知。在这里，我们表明，半月形细胞与苔藓细胞一样，起源于发育神经发生的最早阶段，并且早期出生的神经元彼此之间形成了年龄匹配的回路。除了形态之外，成年半月形细胞还表现出特征性的电生理特征，这些特征与大多数神经元不同，但在早期出生的颗粒细胞中是共有的。因此，早期的出生日期决定了成年颗粒细胞的生理学和连接性，而其他因素可能结合起来产生形态同一性。
