Loss of dopamine terminals in the medial prefrontal cortex increased the ratio of DOPAC to DA in tissue of the nucleus accumbens shell: role of stress
Loss of dopamine terminals in the medial prefrontal cortex increased the ratio of DOPAC to DA in tissue of the nucleus accumbens shell: role of stress
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DOI：
10.1016/s0006-8993(97)00534-9
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发表时间：
1997-09-05
期刊：
影响因子：
2.9
通讯作者：
Finlay, JM
中科院分区：
文献类型：
--
作者：
King, D;Finlay, JM
我们研究了大鼠内侧前额叶皮质的多巴胺缺乏是否会不同地影响新纹状体和伏隔核各亚区基础和诱发的多巴胺和3，4-二羟基苯乙酸(DOPAC)的含量。前额叶内侧皮质组织中近80%的多巴胺含量的丧失并没有显著改变基础组织中多巴胺或DOPAC的浓度，也没有显著改变伏隔核核心或外壳以及新纹状体内侧或外侧的DOPAC/多巴胺比率。但尾压应激显著增加毁损大鼠伏隔核壳层DOPAC/多巴胺的比值。由于内侧前额叶皮质的背侧和腹侧区域分别优先支配核心和外壳，我们试图确定损伤对伏核外壳中多巴胺终末的选择作用是否与腹侧前额叶皮质中更大的多巴胺丢失平行。6-羟基多巴胺降低了背侧(-74%)和腹侧前额叶皮质(-68%)的多巴胺组织浓度。在损毁大鼠，前额叶背内侧皮质仅有少量酪氨酸羟化酶免疫反应纤维残留，而腹侧区仍有密集的神经支配。目前的数据表明，中皮质多巴胺神经元对多巴胺投射到伏核外壳的影响只有在应激条件下才表现出来。更重要的是。病变引起投射到伏核外壳的多巴胺神经元的改变并不是由于腹侧的多巴胺终末比背侧前额叶皮质更广泛的多巴胺终末丢失所致。(C)1997年爱思唯尔科学公司。
We examined whether dopamine depletion in the medial prefrontal cortex of the rat differentially affects basal and evoked dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) content in the subareas of the neostriatum and nucleus accumbens. Loss of approximate to 80% of tissue dopamine content in the medial prefrontal cortex did not significantly alter basal tissue concentrations of dopamine or DOPAC or the DOPAC:dopamine ratio in either the nucleus accumbens core or shell or the medial or lateral neostriatum. However, tail pressure stress significantly increased the DOPAC:dopamine ratio in the nucleus accumbens shell of lesioned rats. Because dorsal and ventral areas of the medial prefrontal cortex preferentially innervate the core and shell, respectively, we sought to determine whether the selective effect of lesions on dopamine terminals in the shell of the nucleus accumbens are paralleled by greater dopamine loss in the ventral medial prefrontal cortex. 6-Hydroxydopamine decreased tissue concentrations of dopamine in both the dorsal (-74%) and ventral medial prefrontal cortex (-68%). In lesioned rats, few tyrosine hydroxylase-immunoreactive fibers remained in the dorsal medial prefrontal cortex whereas a dense innervation remained in the ventralmost area. The present data suggest that the influence of mesocortical dopamine neurons on the dopamine projection to the nucleus accumbens shell is expressed only under conditions of stress. Furthermore. lesion-induced alterations in dopamine neurons projecting to the nucleus accumbens shell are not due to a more extensive loss of dopamine terminals in the ventral than in the dorsal medial prefrontal cortex. (C) 1997 Elsevier Science B.V.