Dubuc R, Rossignol S
Département de Physiologie, Faculté de Médecine, Université de Montréal, Que. Canada.
Brain Res. 1989 Jul 10;491(2):349-55. doi: 10.1016/0006-8993(89)90069-3.
The administration of 4-aminopyridine (4-AP) in decerebrate paralyzed cats induces centrifugal rhythmic discharges in both ventral and dorsal roots. This study describes the mode of discharge of individual primary afferents as well as some ventral root fibers. Several patterns of antidromic discharge have been observed in primary afferents after the administration of 4-AP. A large proportion of the units (n = 96; 53%) showed rhythmic bursts of discharge related (n = 41) or not (n = 55) to the ongoing rhythmic activity in the peripheral nerves. Other units (n = 86; 47%) discharged either tonically, sporadically or had no antidromic activity at all. The conduction velocity of the non-bursting units was significantly higher (89.7 +/- 18.4 m/s) than that of the bursting units (70.6 +/- 15.4 m/s; P less than 0.01). Ventral roots showed rhythmic activity although less intense than that of the dorsal roots. As in dorsal roots, some fibers showed a rhythmical pattern of discharge related to the mass activity recorded from whole dorsal roots or peripheral nerves, while other units were not related. It is concluded that bursting activity which occurs in peripheral nerves after the administration of 4-AP is mainly the result of the antidromic activation of medium to small size primary afferent fibers.
在去大脑麻痹的猫中给予4-氨基吡啶（4-AP）会在腹根和背根中诱发离心性节律性放电。本研究描述了单个初级传入纤维以及一些腹根纤维的放电模式。在给予4-AP后，在初级传入纤维中观察到了几种逆向放电模式。很大一部分单位（n = 96；53%）表现出与外周神经中正在进行的节律性活动相关（n = 41）或不相关（n = 55）的节律性放电爆发。其他单位（n = 8,6；47%）要么持续放电、偶尔放电，要么根本没有逆向活动。非爆发性单位的传导速度（89.7 +/- 18.4米/秒）显著高于爆发性单位（70.6 +/- 15.4米/秒；P < 0.01）。腹根表现出节律性活动，尽管不如背根强烈。与背根一样，一些纤维表现出与从整个背根或外周神经记录到的群体活动相关的节律性放电模式，而其他单位则不相关。得出的结论是，给予4-AP后外周神经中出现的爆发性活动主要是中到小尺寸初级传入纤维逆向激活的结果。
