Guenaire C, Delacour J
Physiol Behav. 1983 Aug;31(2):159-66. doi: 10.1016/0031-9384(83)90113-0.
Rats of the Roman strains, Roman High Avoidance (RHA), Roman Low Avoidance (RLA) and Roman Control Avoidance (RCA) were submitted to 5 conditioning sessions in a two-way shuttle box; the sessions were separated by a 24 hr-interval. Two indices were computed: a within-session progression index W and an inter-session progression index I. Index W was comparable in all three strains; index I was strongly negative in RLA and equal to zero or slightly positive in RHA rats. Lesion of the hippocampal commissure (HC) significantly facilitated CAR acquisition in RLA by making index I less negative: performances of RCA and RHA rats were unaffected. Lesions of the centro medianum parafascicularis nuclei of the thalamus (CM) significantly impaired acquisition of CAR in RCA and RHA by making index I more negative; performances of RLA rats were unaffected. Neither lesion altered index W. These results support the "freezing hypothesis" in the explanation of the Roman strain differences. They are in agreement with recent data on the emotional characteristics of the Roman strains and on the role of octopamine in avoidance behavior.
将罗马品系的大鼠，即罗马高回避型（RHA）、罗马低回避型（RLA）和罗马对照回避型（RCA），置于双向穿梭箱中进行5次条件训练；训练 sessions 间隔24小时。计算了两个指标：session 内进展指数W和session 间进展指数I。指数W在所有三个品系中相当；指数I在RLA中呈强阴性，在RHA大鼠中等于零或略呈阳性。海马连合（HC）损伤通过使指数I的负值减小，显著促进了RLA中CAR的习得：RCA和RHA大鼠的表现未受影响。丘脑中央中核束旁核（CM）损伤通过使指数I的负值增加，显著损害了RCA和RHA中CAR的习得；RLA大鼠的表现未受影响。两种损伤均未改变指数W。这些结果支持了在解释罗马品系差异时的“冻结假说”。它们与最近关于罗马品系的情绪特征以及章鱼胺在回避行为中的作用的数据一致。
