Dombrowski S M, Barbas H
Department of Behavioral Neuroscience, Boston University School of Medicine, MA, USA.
Neuroscience. 1996 May;72(1):49-62. doi: 10.1016/0306-4522(95)00539-0.
The prefrontal cortex of primates is an integrative centre for sensory, cognitive, mnemonic and emotional processes. The cellular features which contribute to the functional specialization of its subsectors are poorly understood. In this study we determined the distribution of nicotinamide adenine dinucleotide phosphate-diaphorase-positive neurons in structurally and functionally distinct prefrontal cortices in the rhesus monkey. This class of neurons express nitric oxide synthase which is necessary for the production of nitric oxide, a novel neural messenger implicated in learning and memory. The density of diaphorase-positive neurons was approximately four times higher in olfactory areas than in eulaminate areas (areas 9, 10, 12, 46, and 8), and two- to three-times higher in the agranular limbic area PAll than in eulaminate areas. Positive neurons were concentrated in a deep band (layers V and VI), a superficial band (layers II and upper III), and were sparsely distributed in the central, thalamic recipient zone (deep layer III, layer IV and upper V). The highest densities of positive neurons were observed in the white matter where their prevalence followed the opposite trend than in the corresponding overlying cortices. The distribution of diaphorase-positive neurons was correlated with the regional anatomic and functional specialization of prefrontal cortices. Thus, diaphorase-positive neurons were most densely distributed in orbital and then medial prefrontal limbic cortices which have a low cell density and widespread connections. In contrast, positive neurons were comparatively sparse in eulaminate cortices, which have a high cell density and more restricted connections. These findings indicated that the distribution of diaphorase-positive neurons in prefrontal cortices is not random, but is associated with the structural architecture and functional attributes of these cortices. The preponderance of diaphorase-positive neurons in limbic cortices, which have been implicated in learning and memory, is consistent with the idea that nitric oxide may have a role in synaptic plasticity.
灵长类动物的前额叶皮质是感觉、认知、记忆和情感过程的整合中心。对其各亚区功能特化所涉及的细胞特征了解甚少。在本研究中，我们确定了恒河猴结构和功能不同的前额叶皮质中烟酰胺腺嘌呤二核苷酸磷酸 - 黄递酶阳性神经元的分布。这类神经元表达一氧化氮合酶，而一氧化氮合酶是产生一氧化氮所必需的，一氧化氮是一种与学习和记忆有关的新型神经信使。黄递酶阳性神经元的密度在嗅觉区比在板层区（9区、10区、12区、46区和8区）高约四倍，在无颗粒边缘区PAll比在板层区高两到三倍。阳性神经元集中在一个深层带（V层和VI层）、一个浅层带（II层和III层上部），并稀疏分布在中央丘脑接受区（III层深部、IV层和V层上部）。在白质中观察到阳性神经元的密度最高，其分布趋势与相应的上层皮质相反。黄递酶阳性神经元的分布与前额叶皮质的区域解剖和功能特化相关。因此，黄递酶阳性神经元最密集地分布在眶额和内侧前额叶边缘皮质，这些皮质细胞密度低且连接广泛。相比之下，阳性神经元在板层皮质中相对较少，板层皮质细胞密度高且连接更受限。这些发现表明，前额叶皮质中黄递酶阳性神经元的分布不是随机的，而是与这些皮质的结构架构和功能属性相关。在与学习和记忆有关的边缘皮质中黄递酶阳性神经元占优势，这与一氧化氮可能在突触可塑性中起作用的观点一致。
