Yim C Y, Mogenson G J
Brain Res. 1980 Jan 13;181(2):301-13. doi: 10.1016/0006-8993(80)90614-9.
Extracellular recordings were obtained from single neurons in the ventral tegmental area of rats anesthetized with urethane. It was found that the area appeared to contain two groups of neurons with distinctly different spike durations, firing rates and firing patterns. One group (group A) had properties similar to those of nigral dopaminergic neurons: slow random firing rates, unusually long spike durations and slow conduction velocities. The discharge rate of the majority of these neurons was reduced by iontophoretically applied dopamine. It was concluded that neurons of this group were probably A10 dopaminergic neurons. The other group (group B) had relatively faster and rhythmical firing rates, short spike durations and faster conduction velocities and were considered to be non-dopaminergic. Forty-nine units in the ventral tegmental area were antidromically activated by electrical stimulation of the nucleus accumbens. Units antidromically activated included neurons of group A and group B, suggesting that the nucleus accumbens received dural projections of dopaminergic and non-dopaminergic fibres from the ventral tegmental area. The discharge rate of 141 out of 142 neurons tested in the ventral tegmental area (group A: 66/66, group B: 75/76) was found to be reduced by GABA. The inhibition was blocked by the simultaneous application of picrotoxin. Picrotoxin alone activated 47.7% of 155 units tested. These results provide further evidence of a GABAergic input to dopaminergic and non-dopaminergic neurons projecting to the limbic forebrain structures.
从用乌拉坦麻醉的大鼠腹侧被盖区的单个神经元进行细胞外记录。发现该区域似乎包含两组神经元，它们的峰电位持续时间、放电频率和放电模式明显不同。一组（A组）具有与黑质多巴胺能神经元相似的特性：缓慢的随机放电频率、异常长的峰电位持续时间和缓慢的传导速度。这些神经元中的大多数的放电率通过离子电泳施加多巴胺而降低。得出的结论是，该组神经元可能是A10多巴胺能神经元。另一组（B组）具有相对较快且有节律的放电频率、短的峰电位持续时间和较快的传导速度，被认为是非多巴胺能的。通过对伏隔核的电刺激逆向激活了腹侧被盖区的49个单位。逆向激活的单位包括A组和B组的神经元，这表明伏隔核接受来自腹侧被盖区的多巴胺能和非多巴胺能纤维的直接投射。在腹侧被盖区测试的142个神经元中有141个（A组：66/66，B组：75/76）的放电率被GABA降低。这种抑制作用被同时应用苦味毒阻断。单独应用苦味毒激活了所测试的155个单位中的47.7%。这些结果为向边缘前脑结构投射的多巴胺能和非多巴胺能神经元的GABA能输入提供了进一步的证据。
