Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.
Cereb Cortex. 2013 Jun;23(6):1299-316. doi: 10.1093/cercor/bhs103. Epub 2012 May 16.
Neocortical areas are organized in columns, which form the basic structural and functional modules of intracortical information processing. Using voltage-sensitive dye imaging and simultaneous multi-channel extracellular recordings in the barrel cortex of newborn rats in vivo, we found that spontaneously occurring and whisker stimulation-induced gamma bursts followed by longer lasting spindle bursts were topographically organized in functional cortical columns already at the day of birth. Gamma bursts synchronized a cortical network of 300-400 µm in diameter and were coherent with gamma activity recorded simultaneously in the thalamic ventral posterior medial (VPM) nucleus. Cortical gamma bursts could be elicited by focal electrical stimulation of the VPM. Whisker stimulation-induced spindle and gamma bursts and the majority of spontaneously occurring events were profoundly reduced by the local inactivation of the VPM, indicating that the thalamus is important to generate these activity patterns. Furthermore, inactivation of the barrel cortex with lidocaine reduced the gamma activity in the thalamus, suggesting that a cortico-thalamic feedback loop modulates this early thalamic network activity.
新皮层区域组织在柱中，这些柱构成了皮质内信息处理的基本结构和功能模块。使用电压敏感染料成像和在新生大鼠桶状皮层的体内同时进行的多通道细胞外记录，我们发现自发发生的和胡须刺激诱导的γ爆发，随后是持续时间更长的纺锤波爆发，在出生当天就在功能皮质柱中呈现出地形组织。γ爆发同步了一个直径为 300-400μm 的皮质网络，并且与同时在丘脑腹后内侧核 (VPM) 记录的γ活动相干。可以通过 VPM 的局部电刺激引发皮质γ爆发。胡须刺激诱导的纺锤波和γ爆发以及大多数自发发生的事件，通过 VPM 的局部失活而显著减少，表明丘脑对产生这些活动模式很重要。此外，用利多卡因失活桶状皮层会降低丘脑中的γ活动，表明皮质-丘脑反馈回路调节这种早期的丘脑网络活动。
