Pollard C E, Angel A
Department of Biomedical Sciences, The University, Sheffield, U.K.
Brain Res. 1990 Jun 4;518(1-2):120-6. doi: 10.1016/0006-8993(90)90962-b.
A slice preparation of rat somatosensory cortex has been used to observe the nature of spontaneous single cell discharge in layer V. On the basis of their discharge pattern, cells recorded using extracellular microelectrodes fell in to one of two categories: 70% of cells discharged single action potentials separated by relatively constant time intervals, while the remainder discharged in bursts of 2-7 action potentials. The firing patterns and the range of discharge frequencies observed were similar to those recorded in the same region and layer of the cortex in urethane-anaesthetized rats. However, unlike cells recorded in vivo, the majority of cells in slices never changed their discharge pattern. This suggests that while these layer V cells in cortical slices have the basic ability to discharge spontaneously, the potential for switching between discharge patterns requires circuitry absent from this isolated preparation. Urethane, over the dose range 6-24 mM, caused a dose-dependent decrease in the discharge frequency of cells with a regular firing pattern but did not affect their basic pattern of discharge.
大鼠体感皮层切片标本已被用于观察V层中自发单细胞放电的性质。根据放电模式，使用细胞外微电极记录的细胞可分为两类：70%的细胞发放单个动作电位，其间隔时间相对恒定，其余细胞则以2 - 7个动作电位的爆发形式发放。观察到的放电模式和放电频率范围与在氨基甲酸乙酯麻醉的大鼠同一皮层区域和层中记录到的相似。然而，与在体记录的细胞不同，切片中的大多数细胞从未改变其放电模式。这表明，虽然皮层切片中的这些V层细胞具有自发放电的基本能力，但在不同放电模式之间切换的潜力需要这种离体标本中不存在的神经回路。在6 - 24 mM的剂量范围内，氨基甲酸乙酯使具有规则放电模式的细胞放电频率呈剂量依赖性降低，但不影响其基本放电模式。
