Metzger D, Alescio-Lautier B, Soumireu-Mourat B
Laboratoire de Neurobiologie des Comportements, CNRS-URA 372, Université de Provence, Marseille, France.
Behav Neural Biol. 1994 Sep;62(2):90-9. doi: 10.1016/s0163-1047(05)80030-5.
Biochemical investigations show that vasopressin interacts with noradrenalin to potentiate noradrenalin-induced accumulation of cyclic-AMP in the hippocampus, via the beta-adrenergic receptors. We previously showed in BALB/c mice that the effects of vasopressin (bilaterally injected at a 25-pg dose) in the ventral hippocampus were more effective than in the dorsal hippocampus on the retrieval and relearning of a Go-No Go visual discrimination task. Considering our results and those reported by biochemical investigations, we evaluated possible noradrenergic-vasopressinergic interaction in the ventral hippocampus under our behavioral conditions. To do so, we first explored the effects of propranolol and phentolamine, antagonists of beta- and alpha-adrenergic receptors, respectively. Second, we assessed the modifications in the vasopressin-induced improvement of retrieval and relearning by pretreating the subjects with either propranolol or phentolamine. Third, we tested the treatments in a locomotor activity task to determine whether the effects demonstrated in the two preceding experiments could be partially due to locomotor alterations by the drug. The results indicated that bilateral injection of propranolol (1 microgram on each side), which did not appear to affect the retention performance itself, completely blocked the enhancement of retrieval and relearning resulting from the vasopressin treatment. In contrast, bilateral injection of phentolamine (1 microgram on each side), which moderately improved retrieval, enhanced the vasopressin effect. The present results lend further support to the view that both noradrenalin and vasopressin play important roles in retrieval and relearning processes. More importantly, they provide additional support for the functional interaction of the noradrenergic and vasopressinergic hippocampal systems.
生化研究表明，血管加压素与去甲肾上腺素相互作用，通过β-肾上腺素能受体增强去甲肾上腺素诱导的海马体中环磷酸腺苷的积累。我们之前在BALB/c小鼠中发现，双侧注射25皮克剂量的血管加压素，其在腹侧海马体中的作用比在背侧海马体中对“Go-No Go视觉辨别任务”的记忆提取和重新学习更为有效。考虑到我们的研究结果以及生化研究报告的结果，我们评估了在我们的行为条件下，腹侧海马体中可能存在的去甲肾上腺素能-血管加压素能相互作用。为此，我们首先探究了分别作为β-和α-肾上腺素能受体拮抗剂的普萘洛尔和酚妥拉明的作用。其次，我们评估了用普萘洛尔或酚妥拉明预处理实验对象后，血管加压素诱导的记忆提取和重新学习改善情况的变化。第三，我们在运动活动任务中测试了这些处理方法，以确定前两个实验中所显示的效果是否可能部分归因于药物引起的运动改变。结果表明，双侧注射普萘洛尔（每侧1微克），这似乎本身并不影响记忆保持表现，但完全阻断了血管加压素治疗所导致的记忆提取和重新学习的增强。相反，双侧注射酚妥拉明（每侧1微克），其适度改善了记忆提取，增强了血管加压素的作用。目前的结果进一步支持了去甲肾上腺素和血管加压素在记忆提取和重新学习过程中都发挥重要作用的观点。更重要的是，它们为去甲肾上腺素能和血管加压素能海马体系统的功能相互作用提供了额外的支持。
