Jurna I, Grossman W
Exp Brain Res. 1976 Mar 15;24(5):473-84. doi: 10.1007/BF00234964.
The effect of morphine on the activity in ventrolateral tract axons was studied in intercollicularly decerebrate cats with and without spinal section. Activity was elicited by electrical stimulation of Adelta- and C-fibres in the sural nerves. In spinal animals, morphine injected intravenously in a dose as low as 0.5 mg/kg reduced the post-stimulus discharge of impulses recorded in ventrolateral tract axons below the site of transection. The depression was not only abolished but reversed by levallorphan and naloxone. Pretreatment with reserpine did not diminish the effect of morphine. The effect of morphine was considerably weaker in decerebrate cats. Reversible block of the spinal cord produced by cold revealed that morphine reduced inhibition from the brain stem controlling the impulse transmission to ventrolateral tract axons. It is concluded that a spinal effect contributes to the analgesic action of morphine.
在去大脑猫（有或没有脊髓横断）中研究了吗啡对脊髓腹外侧束轴突活动的影响。通过电刺激腓肠神经中的Aδ纤维和C纤维来引发活动。在脊髓动物中，静脉注射低至0.5mg/kg剂量的吗啡可减少在横断部位以下的脊髓腹外侧束轴突中记录到的刺激后冲动发放。这种抑制不仅被烯丙左吗喃和纳洛酮消除，而且被逆转。利血平预处理并没有减弱吗啡的作用。吗啡对去大脑猫的作用明显较弱。寒冷引起的脊髓可逆性阻断表明，吗啡减少了来自控制向脊髓腹外侧束轴突冲动传递的脑干的抑制作用。得出的结论是，脊髓效应有助于吗啡的镇痛作用。
