González A S, Rodríguez Echandía E L, Cabrera R, Fóscolo M R, Fracchia L N
Laboratorio de Investigaciones Cerebrales (LINCE), Facultad de Ciencias Médicas Universidad Nacional de Cuyo, Mendoza, Argentina.
Physiol Behav. 1990 Apr;47(4):735-41. doi: 10.1016/0031-9384(90)90087-k.
An influence of early stimulation on sensitivity to acute stress in adulthood has been reported. The purpose of the present work was to determine the effect of exposure of male and female rats to three models of chronic stress (unpredictable stress, cold stress and handling) from day 2 to day 15 of life on behavioral and endocrine sensitivity to chronic stresses in adulthood. The chronic stresses applied in adulthood were a model of intermittent cold stress (daily 30-min sessions at -20 degrees C for 15 days) and the Katz's model of unpredictable chronic stress (15 days). Forced swim behavior and serum concentration of the stress-sensitive hormones, corticosterone and prolactin, were chosen to investigate stress sensitivity. It was found that all neonatal treatments stimulated body weight gain, did not cause infant mortality and did not affect forced swim behavior as adult. The repetitive exposure to cold stress in adulthood did not cause major impairment of forced swim behavior and did not affect basal levels of serum corticosterone and prolactin in either control or experimental rats. These findings support the view that repeated stressors can induce behavioral and endocrine adaptation in rats. The neonatal treatments did not affect this characteristic. The exposure of control rats to the unpredictable stress model severely impaired forced swim behavior and increased basal levels of serum corticosterone and prolactin. This observation conforms to the view that standard laboratory rats cannot adapt to unpredictable chronic stress. This has been reported to cause a behavioral depression syndrome comprising forced swim deficit and endocrine alterations.(ABSTRACT TRUNCATED AT 250 WORDS)
据报道，早期刺激对成年期急性应激敏感性有影响。本研究的目的是确定从出生后第2天到第15天，将雄性和雌性大鼠暴露于三种慢性应激模型（不可预测应激、冷应激和处理）对成年期行为和内分泌对慢性应激的敏感性的影响。成年期施加的慢性应激是间歇性冷应激模型（每天在-20℃下进行30分钟，持续15天）和Katz不可预测慢性应激模型（15天）。选择强迫游泳行为以及应激敏感激素皮质酮和催乳素的血清浓度来研究应激敏感性。结果发现，所有新生期处理均促进体重增加，未导致幼崽死亡，且对成年后的强迫游泳行为无影响。成年期反复暴露于冷应激并未导致强迫游泳行为严重受损，也未影响对照组或实验组大鼠血清皮质酮和催乳素的基础水平。这些发现支持了反复应激源可诱导大鼠行为和内分泌适应的观点。新生期处理并未影响这一特性。将对照大鼠暴露于不可预测应激模型会严重损害强迫游泳行为，并增加血清皮质酮和催乳素的基础水平。这一观察结果符合标准实验室大鼠无法适应不可预测慢性应激的观点。据报道，这会导致一种行为抑郁综合征，包括强迫游泳缺陷和内分泌改变。（摘要截短至250字）
