Martijena I D, Calvo N, Volosin M, Molina V A
Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
Brain Res. 1997 Mar 28;752(1-2):136-42. doi: 10.1016/s0006-8993(96)01465-5.
The influence of two different stressors on the behavioral and neurochemical responses to a subsequent exposure to the elevated plus maze (EPM) was examined. Rats were submitted to either a 15-min restraint period or to a 15-min forced swimming test (FS) and one day later exposed to the EPM. Animals with early restraint exhibited a significant decrease in the percent time spent and in the number of entries on the open arms. In addition, restraint induced a reduction in the total number of entries. An identical behavior in the EPM was observed between unstressed rats and those exposed to a previous swimming experience. As a humoral index of stress, corticosterone (CS) secretion in response to each stressor was evaluated. A similar increase of CS release was observed following each aversive stimulus. Exposure to both restraint and EPM decreased the cortical chloride uptake following GABA stimulation. Similar values of chloride flux were obtained from animals submitted to either restraint but without subsequent exposure to the EPM, exposed only to the EPM, or without any manipulation (controls). These findings are discussed in terms of a facilitated behavioral and neurochemical response to a fearful situation following an early and brief restraint experience.
研究了两种不同应激源对大鼠随后暴露于高架十字迷宫（EPM）时行为和神经化学反应的影响。将大鼠置于15分钟的束缚期或15分钟的强迫游泳试验（FS）中，一天后使其暴露于EPM。早期经历束缚的动物在开放臂上花费的时间百分比和进入次数显著减少。此外，束缚导致总进入次数减少。在未受应激的大鼠和先前有过游泳经历的大鼠之间，观察到在EPM中的行为相同。作为应激的体液指标，评估了每种应激源引起的皮质酮（CS）分泌。在每种厌恶刺激后，观察到CS释放有类似增加。暴露于束缚和EPM都会降低γ-氨基丁酸（GABA）刺激后的皮质氯化物摄取。从仅经历束缚但随后未暴露于EPM的动物、仅暴露于EPM的动物或未进行任何操作的动物（对照组）中获得了类似的氯化物通量值。根据早期短暂束缚经历后对恐惧情境的行为和神经化学反应的易化来讨论这些发现。
