Hippocampal and prefrontal cortical inputs monosynaptically converge with individual projection neurons of the nucleus accumbens
Hippocampal and prefrontal cortical inputs monosynaptically converge with individual projection neurons of the nucleus accumbens
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DOI：
10.1002/cne.10191
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发表时间：
2002-04-29
影响因子：
2.5
通讯作者：
Totterdell, S
中科院分区：
文献类型：
--
作者：
French, SJ;Totterdell, S
来自不同来源的伏隔核传入神经支配中央“核”和外围“壳”的特定区域，并且在光学显微镜水平上以复杂的重叠和非重叠方式相互关联。这种同质性的缺乏表明，该区域由涉及神经元集合的电路组成，这些神经元集合由特定集合的收敛传入输入调节，这种集合的异常调节与精神障碍有关。早期的细胞外研究表明，单个Acb神经元可能对来自多个兴奋性输入的传入事件的激活做出反应：最近对海马和杏仁核或前额皮质传入事件的研究表明，海马传入事件限制了来自前额皮质或杏仁核的输入。兴奋性传入事件在Acb中收敛的电生理证据是强有力的，并表明这些通路是单突触的。然而，由于传入输入在目标神经元树突树上的空间分布，这种收敛性很难从解剖学上证明。为了确定个别伏隔神经元是否接受来自一对传入事件的单突触输入，我们分别用普通Phaseolus vulgaris白细胞凝集素顺行标记一个投影，用生物素化葡聚糖胺（BDA）标记另一个投影，其中BDA以载体板岩灰和3,3'-二氨基苯胺四盐酸作为染色原。通过体内局灶性注射BDA标记可能与这些传入事件发生突触后的伏隔神经元，使用相关光镜和电子显微镜进行检查，以建立标记的传入突触输入在其树突上的近端-远端分布。单个细胞可以同时接收来自腹侧下带和前额叶皮层的单突触传入输入，这为海马门控其他边缘输入到伏隔区提供了解剖学框架。(C) 2002 Wiley-Liss, Inc。
Afferents to the nucleus accumbens from different sources innervate specific areas of the central "core" and peripheral "shell" and are related to each other, at the light microscopical level, in an intricate overlapping and nonoverlapping way. This lack of homogeneity suggests that this region consists of circuits involving emsembles of neurons modulated by specific sets of convergent afferent inputs and abnormal regulation of such ensembles has been implicated in mental disorders. Early extracellular studies suggested that individual Acb neurons might respond to activation of afferents from more than one excitatory input: More recent studies of hippocampal and amygdalar or prefrontal cortical afferents suggest that hippocampal afferents gate the input from the prefrontal cortex or amygdala. Electrophysiological evidence for convergence of excitatory afferents in the Acb is strong and suggests that these pathways are monosynaptic. Nevertheless, this convergence has proved difficult to demonstrate anatomically as a result of the spatial distribution of the afferent inputs on the dendritic tree of the target neurons. To establish whether individual accumbens neurons receive monosynaptic input from pairs of afferents, one projection was labelled anterogradely with Phaseolus vulgaris leucoagglutinin and the second with biotinylated dextran amine (BDA) with Vector slate grey and 3,3'-diaminobenzidine tetrahydrochloride as the chromagens. Accumbens neurons possibly postsynaptic to these afferents, labelled by an in vivo focal injection of BDA, were examined using correlated light and electron microscopy to establish the proximal-distal distribution of labelled afferent synaptic inputs on their dendritic arbours. Individual cells were shown to receive monosynaptic afferent input from both ventral subiculum and prefrontal cortex, providing an anatomical framework for the hippocampal gating of other limbic inputs to the accumbens. (C) 2002 Wiley-Liss, Inc.