Niemi-Junkola U J, Westby G W
Department of Psychology, Sheffield University, UK.
Neurosci Lett. 1998 Jan 30;241(2-3):175-9. doi: 10.1016/s0304-3940(97)00956-7.
Superior colliculus (SC)-mediated behaviours are under the disinhibitory control of the striato-nigro-collicular projection. We systematically investigated the homogeneity of substantia nigra pars reticulata (SNr) influence on different populations of SC neurons by recording the effects of intranigral GABA microinjections on 149 cells at different locations in the rat SC. Suppression of the tonic activity of SNr resulted in both the facilitation and paradoxical inhibition of spatially-segregated SC target neurons. These dual influences were found to broadly map onto the SC origins of the descending projections known to support approach and avoidance/defensive behaviours. These findings are consistent with an organisation which promotes contrasting processes for the selection of a behaviour and simultaneous suppression of competing motor programs.
上丘（SC）介导的行为受纹状体 - 黑质 - 上丘投射的去抑制控制。我们通过记录向大鼠SC不同位置的149个细胞内注射GABA对黑质网状部（SNr）的影响，系统地研究了SNr对不同群体SC神经元影响的同质性。SNr紧张性活动的抑制导致空间隔离的SC靶神经元的易化和反常抑制。发现这些双重影响大致映射到已知支持趋近和回避/防御行为的下行投射的SC起源上。这些发现与一种组织方式一致，该组织方式促进了行为选择的对比过程以及对竞争性运动程序的同时抑制。
