Ikeda S R, Schofield G G, Weight F F
J Neurophysiol. 1986 Mar;55(3):527-39. doi: 10.1152/jn.1986.55.3.527.
The electrical properties of nodose ganglion cells acutely isolated from adult rats were studied using the whole-cell patch-clamp recording method. Current-clamp recordings revealed a mean resting membrane potential of -54.3 mV and an input resistance of 527 M omega. Depolarizing current steps evoked action potentials with the following properties (mean): amplitude 111 mV, threshold -36 mV, and rate of rise 117 V/s. Two types of action potentials were observed, short and long duration. These properties, with the exception of input resistance (527 M omega cf. 50 M omega), are similar to those reported previously using intracellular recording methods in intact nodose ganglia (11, 20, 28). Brief application of 10 microM 5-hydroxytryptamine resulted in a rapid depolarization and burst of action potentials in the majority of cells. With voltage-clamp recording, step depolarizations to potentials positive to -10 mV elicited a transient inward current that was followed by a sustained outward current. Inward Na+ current was isolated by ion substitution and pharmacological agents. Two types of Na+ current were observed. One current was completely abolished by 3-15 microM tetrodotoxin (TTX), had a rapid time course, activated over the potential range -60 to -10 mV, and attained half-maximal conductance at -30 mV. The other current persisted in the presence of 15 microM TTX, had a slower time course, activated over the potential range -30 to 0 mV, and attained half-maximal conductance at -15 mV. In addition, 500 microM Cd2+ and 5.0 mM Co2+ reduced the TTX-insensitive current to 53 and 42% of control, respectively. Inward Ca2+ current was isolated by ion substitution and pharmacological agents and was identified by a dependence on external Ca2+. Cd2+ (500 microM) and Co2+ (5 mM) reduced the maximal inward current to 5 and 20% of control, respectively. When Ba2+ was substituted for Ca2+ as the charge carrier, the maximal inward current increased to 175% of control. Some cells had two Ca2+ current components, an inactivating component that activated near -60 mV and a large sustained current that activated near -40 mV. The initial inactivating current appeared as a "hump" on the current-voltage (I-V) curve over the potential range of -60 to -30 mV. The results indicate that, following isolation of these adult mammalian neurons, the membrane surfaces are sufficiently clean to allow patch-clamp recording.(ABSTRACT TRUNCATED AT 400 WORDS)
采用全细胞膜片钳记录法，对成年大鼠急性分离的结状神经节细胞的电特性进行了研究。电流钳记录显示，平均静息膜电位为-54.3 mV，输入电阻为527 MΩ。去极化电流阶跃诱发的动作电位具有以下特性（平均值）：幅度111 mV，阈值-36 mV，上升速率117 V/s。观察到两种类型的动作电位，即短持续时间和长持续时间的动作电位。除输入电阻外（527 MΩ 对比 50 MΩ），这些特性与先前在完整结状神经节中使用细胞内记录方法所报道的特性相似（11, 20, 28）。短暂施加10 μM 5-羟色胺可导致大多数细胞快速去极化并爆发动作电位。在电压钳记录中，向正于-10 mV的电位进行阶跃去极化会诱发一个短暂的内向电流，随后是一个持续的外向电流。通过离子置换和药理学试剂分离出内向Na⁺电流。观察到两种类型的Na⁺电流。一种电流被3 - 15 μM河豚毒素（TTX）完全阻断，具有快速的时间进程，在-60至-10 mV的电位范围内激活，在-30 mV时达到半数最大电导。另一种电流在15 μM TTX存在时仍然存在，具有较慢的时间进程，在-30至0 mV的电位范围内激活，在-15 mV时达到半数最大电导。此外，500 μM Cd²⁺和5.0 mM Co²⁺分别将TTX不敏感电流降低至对照的53%和42%。通过离子置换和药理学试剂分离出内向Ca²⁺电流，并通过对细胞外Ca²⁺的依赖性进行鉴定。Cd²⁺（500 μM）和Co²⁺（5 mM）分别将最大内向电流降低至对照的5%和20%。当用Ba²⁺替代Ca²⁺作为电荷载体时，最大内向电流增加至对照值的175%。一些细胞具有两种Ca²⁺电流成分，一种是在接近-60 mV时激活的失活成分，另一种是在接近-40 mV时激活的大的持续电流。初始失活电流在-60至-30 mV的电位范围内的电流-电压（I-V）曲线上表现为一个“驼峰”。结果表明，在分离这些成年哺乳动物神经元后，膜表面足够清洁，可进行膜片钳记录。（摘要截断于400字）
