Allen L F, Inglis W L, Winn P
School of Psychology, University of St Andrews, Fife, Scotland.
Brain Res Bull. 1996;41(4):201-10. doi: 10.1016/s0361-9230(96)00165-7.
The cuneiform nucleus and the pedunculopontine tegmental nucleus have both been suggested as possible sites for the mesencephalic locomotor region (MLR), an area from which controlled stepping on a treadmill can be elicited following electrical or chemical stimulation in a decerebrate animal. It has been shown that excitotoxic lesions of the pedunculopontine tegmental nucleus impair neither spontaneous locomotion nor locomotion induced by stimulation of the nucleus accumbens. Excitotoxic lesions of the cuneiform nucleus have not previously been investigated. Rats received either bilateral ibotenate or sham lesions of the cuneiform nucleus combined with bilateral implantation of guide cannulae aimed at the nucleus accumbens. On recovery from surgery spontaneous locomotion was tested, followed by accumbens-stimulated locomotion. For nucleus accumbens stimulation, each rat received bilateral microinjection of each of three doses of d-amphetamine (10.0, 20.0 and 30.0 micrograms) and a vehicle only injection. Locomotor activity was recorded following the injection. In comparison to the sham-lesioned group, the ibotenate-lesioned group showed no differences in either spontaneous or amphetamine-induced locomotor activity. These results suggest that, like the pedunculopontine tegmental nucleus, the cuneiform nucleus is not involved in the direct mediation of spontaneous or accumbens-induced locomotion, and thus is very unlikely to be the anatomical substrate of the MLR. The role of the cuneiform nucleus in other types of behavioural control is discussed.
楔形核和脚桥被盖核均被认为可能是中脑运动区（MLR）的所在位置，在去大脑动物中，电刺激或化学刺激该区域可引发在跑步机上的受控行走。研究表明，脚桥被盖核的兴奋性毒性损伤既不损害自发运动，也不损害伏隔核刺激诱导的运动。此前尚未对楔形核的兴奋性毒性损伤进行研究。给大鼠双侧注射异搏亭或假损伤楔形核，并双侧植入针对伏隔核的引导套管。大鼠从手术中恢复后，测试其自发运动，随后测试伏隔核刺激诱导的运动。对于伏隔核刺激，每只大鼠接受三种剂量（10.0、20.0和30.0微克）的d-苯丙胺双侧微量注射以及仅注射一次溶剂。注射后记录运动活动。与假损伤组相比，异搏亭损伤组在自发运动或苯丙胺诱导的运动活动方面均无差异。这些结果表明，与脚桥被盖核一样，楔形核不参与自发运动或伏隔核诱导运动的直接调节，因此极不可能是中脑运动区的解剖学基础。本文还讨论了楔形核在其他类型行为控制中的作用。
