Reinoso B S, Pimenta A F, Levitt P
Department of Neuroscience and Cell Biology, University of Medicine and Dentistry of New Jersey/Robert Wood Johnson Medical School, Piscataway 08854.
J Comp Neurol. 1996 Nov 11;375(2):274-88. doi: 10.1002/(SICI)1096-9861(19961111)375:2<274::AID-CNE7>3.0.CO;2-#.
The search for molecular markers common to neural structures that are functionally related has become an attractive strategy for neurobiologists interested in identifying mechanisms involved in the formation of patterned connections. One such molecule is the limbic system-associated membrane protein (LAMP), a 64-68 kDa glycoprotein that is expressed in the soma and dendrites of subpopulations of adult neurons in the brain that are functionally associated with classic limbic structures. Such patterned molecular specificity is established prenatally; LAMP is detected during development on the surface of neurons, axonal membranes and pathfinding growth cones. This molecule has now been cloned (lamp) and has been shown to be highly conserved in rat and human. It is a new immunoglobulin superfamily member that has three Ig domains and a glycosyl-phosphatidylinositol (GPI) anchor to the cell membrane. In this study, the distribution of the lamp transcript in the adult rat brain was determined by using in situ hybridization. Generally, the distribution of lamp corresponds well with that of the LAMP protein. Within the cerebral cortex, the transcript is more abundant in areas that are associated with learning/memory and viscerosensory tasks. It is less abundant in somatic sensory and motor areas. The lamp transcript is also ubiquitous in the basal forebrain, amygdala, and preopticohypothalamic areas. In short, the lamp transcript is expressed heavily in areas of the forebrain and diencephalon that have been classically considered limbic and sparsely or moderately in nonlimbic midbrain and hindbrain regions. Correlative analysis of the connectivity patterns of the regions that express greater amounts of the transcript is consistent with a stronger limbic-associated function relative to the regions expressing less lamp. These quantitative differences may be significant in determining the function of LAMP in the adult brain.
对于功能相关的神经结构中常见分子标记的探寻，已成为对识别参与模式化连接形成机制感兴趣的神经生物学家们所采用的一种颇具吸引力的策略。其中一种这样的分子就是边缘系统相关膜蛋白（LAMP），它是一种64 - 68 kDa的糖蛋白，在大脑中与经典边缘结构功能相关的成年神经元亚群的胞体和树突中表达。这种模式化的分子特异性在出生前就已确立；在发育过程中，LAMP可在神经元表面、轴突膜和引导生长锥上被检测到。该分子现已被克隆（lamp），并已证实在大鼠和人类中高度保守。它是免疫球蛋白超家族的一个新成员，具有三个免疫球蛋白结构域以及一个连接到细胞膜的糖基磷脂酰肌醇（GPI）锚定物。在本研究中，通过原位杂交确定了lamp转录本在成年大鼠脑中的分布。一般来说，lamp的分布与LAMP蛋白的分布非常吻合。在大脑皮层内，转录本在与学习/记忆以及内脏感觉任务相关的区域更为丰富。在躯体感觉和运动区域则较少。lamp转录本在基底前脑、杏仁核和视前 - 下丘脑区域也普遍存在。简而言之，lamp转录本在前脑和间脑那些传统上被认为是边缘系统的区域大量表达，而在非边缘系统的中脑和后脑区域则表达稀少或适中。对表达较多转录本区域的连接模式进行相关分析，结果表明相对于表达较少lamp的区域，其边缘系统相关功能更强。这些数量上的差异在确定LAMP在成年大脑中的功能方面可能具有重要意义。
