Effects of corticosterone on excitatory amino acid responses in dopamine-sensitive neurons in the ventral tegmental area
Effects of corticosterone on excitatory amino acid responses in dopamine-sensitive neurons in the ventral tegmental area
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DOI：
10.1016/s0306-4522(98)00264-4
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发表时间：
1999-02-01
期刊：
影响因子：
3.3
通讯作者：
Little, HJ
中科院分区：
文献类型：
--
作者：
Cho, K;Little, HJ
腹侧被盖区参与奖赏过程和药物依赖，并将多巴胺能投射发送到丘脑核和前额叶皮层。应激和糖皮质激素被认为在药物依赖的发展中起重要作用，但这些激素对腹侧被盖功能的影响很少有研究。本研究探讨了皮质酮对中脑脑片腹侧被盖区多巴胺敏感神经元单单位记录的影响。在100 nM及以上的浓度下，皮质酮增强了对N-甲基-D-天冬氨酸的反应。这种效果是没有看到当钙浓度的洗浴介质降低到0.1 mM。响应α-氨基-3-羟基-5-甲基异恶唑-4-丙酸酯（AMPA）和红藻氨酸也大大增强，在浓度超过100 nM的皮质酮，而有一些证据表明，在这些响应减少在100 nM浓度的这种激素。醛固酮，在100 nM及以上的浓度降低了对N-甲基-D-天冬氨酸的反应，但在较低的浓度没有影响。RU 38486作为糖皮质激素（II型）受体的拮抗剂，可防止皮质酮对N-甲基-D-天冬氨酸反应的影响，对自发放电率或在不存在皮质酮的情况下对N-甲基-D-天冬氨酸的影响无影响。后者的结果，和醛固酮的影响，表明增强的N-甲基-D-天冬氨酸的反应是通过II型糖皮质激素receptors.This研究表明，增强的兴奋性氨基酸的反应皮质酮可能会改变腹侧被盖神经元的功能，在应激过程中，它是可能的，这种效果是参与药物依赖的发展。(C)1998年IBRO。出版社：Elsevier Science Ltd
The ventral tegmental area is involved in reward processes and in drug dependence and sends dopaminergic projections to the nucleus accumbens and prefrontal cortex. Stress, and glucocorticoid hormones, are thought to play an important role in the development of drug dependence, but there has been little investigation of the effects of these hormones on ventral tegmental function. The present study examined the effects of corticosterone on single-unit recordings from dopamine-sensitive neurons in the ventral tegmental area in midbrain slices. At concentrations of 100 nM and above, corticosterone potentiated the responses to N-methyl-D-aspartate. This effect was not seen when the calcium concentration of the bathing medium was reduced to 0.1 mM. Responses to alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) and kainic acid were also considerably potentiated, at concentrations of corticosterone over 100 nM, while there was some evidence of decreases in these responses at the 100 nM concentration of this hormone. Aldosterone, at concentrations of 100 nM and above reduced the responses to N-methyl-D-aspartate, but had no effects at lower concentrations. RU38486, which acts as an antagonist at glucocorticoid (Type II) receptors, prevented the effects of corticosterone on responses to N-methyl-D-aspartate, with no effect on the spontaneous firing rate or on the effects of N-methyl-D-aspartate in the absence of corticosterone. The latter result, and the effects of aldosterone, suggest that the potentiation of responses to N-methyl-D-aspartate was mediated through Type II glucocorticoid receptors.This study suggests that potentiation of responses to excitatory amino acids by corticosterone may alter the function of ventral tegmental neurons during stress, and it is possible that this effect is involved in the development of drug dependence. (C) 1998 IBRO. Published by Elsevier Science Ltd.