Salvatierra N A, Marín R H, Arce A, Martijena I D
Cátedra de Química Biológica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Argentina.
Brain Res. 1994 Jun 13;648(1):39-45. doi: 10.1016/0006-8993(94)91902-x.
One-day-old chicks were selected on their performance in imprinting behaviour and termed high-imprinted (H-I), partially imprinted (P-I) and low-imprinted (L-I) chicks. Then, H-I and L-I chicks were submitted to acute handling stress and [3H]flunitrazepam receptor-binding was performed on synaptosomal membranes from forebrain at various times after handling. The receptor number significantly increased in L-I but not in H-I chicks at 30 min after handling while the affinity remained unchanged at all times. In addition, when the three selected groups were maintained to reach 15 days of age and then they were submitted to acute swimming stress, the degree of receptor increase was also inversely related to the degree of imprinting performance. The receptor increase associated to swimming stress was higher in the left hemisphere, suggesting an interhemispheric asymmetry of stress effects. The results suggest that more-imprinted chicks are less susceptible than less-imprinted chicks to acute stress associated to central benzodiazepine receptor increase, probably due to differences in the degree of endogenous emotionality.
根据雏鸡在印记行为中的表现挑选出一日龄雏鸡，并将其分为高印记（H-I）、部分印记（P-I）和低印记（L-I）雏鸡。然后，对H-I和L-I雏鸡施加急性处理应激，并在处理后的不同时间对前脑突触体膜进行[3H]氟硝西泮受体结合实验。处理后30分钟时，L-I雏鸡的受体数量显著增加，而H-I雏鸡的受体数量未增加，同时亲和力在所有时间均保持不变。此外，当将这三个选定的组饲养至15日龄，然后对它们施加急性游泳应激时，受体增加的程度也与印记表现的程度呈负相关。与游泳应激相关的受体增加在左半球更高，表明应激效应存在半球间不对称性。结果表明，印记程度较高的雏鸡比印记程度较低的雏鸡对与中枢苯二氮䓬受体增加相关的急性应激更不敏感，这可能是由于内源性情绪程度的差异所致。
