Grant Eleanor, Hoerder-Suabedissen Anna, Molnár Zoltán
Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, UK.
Front Neurosci. 2012 May 4;6:53. doi: 10.3389/fnins.2012.00053. eCollection 2012.
In this review we discuss recent advances in the understanding of corticothalamic axon guidance; patterning of the early telencephalon, the sequence and choreography of the development of projections from subplate, layers 5 and 6. These cortical subpopulations display different axonal outgrowth kinetics and innervate distinct thalamic nuclei in a temporal pattern determined by cortical layer identity and subclass specificity. Guidance by molecular cues, structural cues, and activity-dependent mechanisms contribute to this development. There is a substantial rearrangement of the corticofugal connectivity outside the thalamus at the border of and within the reticular thalamic nucleus, a region that shares some of the characteristics of the cortical subplate during development. The early transient circuits are not well understood, nor the extent to which this developmental pattern may be driven by peripheral sensory activity. We hypothesize that transient circuits during embryonic and early postnatal development are critical in the matching of the cortical and thalamic representations and forming the cortical circuits in the mature brain.
在本综述中，我们讨论了在皮质丘脑轴突导向理解方面的最新进展；早期端脑的模式形成，以及来自皮质下板、第5层和第6层的投射发育的顺序和编排。这些皮质亚群表现出不同的轴突生长动力学，并以由皮质层身份和亚类特异性决定的时间模式支配不同的丘脑核。分子线索、结构线索和活动依赖机制的引导有助于这一发育过程。在丘脑外、丘脑网状核边界及内部，皮质离心连接存在大量重排，该区域在发育过程中具有一些皮质下板的特征。早期的瞬态回路尚未得到充分理解，这种发育模式受外周感觉活动驱动的程度也不清楚。我们假设，胚胎期和出生后早期发育过程中的瞬态回路对于皮质和丘脑表征的匹配以及成熟大脑中皮质回路的形成至关重要。
