Karlsson Karl A E, Mohns Ethan J, di Prisco Gonzalo Viana, Blumberg Mark S
Department of Biomedical Engineering, School of Science and Engineering, Reykjavik University, Reykjavik, Iceland.
Hippocampus. 2006;16(11):959-65. doi: 10.1002/hipo.20224.
Hippocampal sharp waves (SPWs) are among the earliest neural population patterns observed in infant mammals. Similarly, startles are among the earliest behavioral events observed. Here we provide evidence indicating that these two events are linked mechanistically soon after birth in freely moving and head-fixed 1 to 4-day-old rats. EMG electrodes and intrahippocampal silicon depth electrodes were used to detect the presence of startles and SPWs, respectively. In intact pups, the majority of sharp waves were preceded by startles (average latency: 161 ms). When the hippocampal formation was surgically separated from the brainstem, however, sharp waves and startles still occurred, but now independently. In addition, unrelated to startles or SPWs, gamma oscillations were detected in several subjects, as were neocortical "spindles" that propagated passively into the hippocampus. The co-occurrence of sharp waves and startles provides the opportunity for Hebbian changes in synaptic efficacy and, thus, is poised to contribute to the assembly of neural circuits early in development.
海马体尖波（SPWs）是在幼年哺乳动物中最早观察到的神经群体模式之一。同样，惊吓反应是最早观察到的行为事件之一。在此，我们提供证据表明，在自由活动和头部固定的1至4日龄大鼠出生后不久，这两种事件在机制上存在联系。肌电图电极和海马体内硅深度电极分别用于检测惊吓反应和SPWs的存在。在完整的幼崽中，大多数尖波之前都有惊吓反应（平均潜伏期：161毫秒）。然而，当海马结构通过手术与脑干分离时，尖波和惊吓反应仍然会出现，但现在是独立出现的。此外，与惊吓反应或SPWs无关，在几个实验对象中检测到了伽马振荡，同时也检测到了被动传播到海马体的新皮质“纺锤波”。尖波和惊吓反应的同时出现为突触效能的赫布式变化提供了机会，因此，有望在发育早期促进神经回路的组装。
