Vibert J F, Bertrand F, Denavit-Saubié M, Hugelin A
Brain Res. 1976 Sep 17;114(2):227-44. doi: 10.1016/0006-8993(76)90668-5.
Results of the preceding paper32 suggest that bulbo-pontine respiration related units (RRU) could be classed into 4 populations according to the relation of their peak firing frequency to the respiratory cycle: one inspiratory (I) and 3 expiratory (E) (early, mid and late). A further study of their spatial distribution is reported. Recorded units totalling 26,520 were distributed through a matrix of unitary cubes of which about 2,000 were found within the limits of the medulla and pons. Both percentage and density of respiratory and non-respiratory units were estimated in each cube. Statistical analysis of unit distribution showed a high probability of finding RRU in certain regions. The probability of finding I and E units in separate cubes was high, whereas there was no probability better than chance for recording one of the 3 E types separately from the 2 others. Therefore, only two populations, I and E, could be considered for spatial analysis. A thresholding technique applied to I and E unit density figures in unitary cubes demonstrated a definite limit for I and E populations. A computerized, three-dimensional (3-D) reconstruction of the outer surfaces of the I and E networks showed that half a medullary system consisted of 2 contiguous and uninterrupted columns extending from the cervical junction up to the pneumotaxic system. The main body of the I population was found in the caudal third and dorsolateral part of the bulbopontine region, while the main body of the E population was in the middle third in a ventromedial position. Both have caudal and rostral extensions that run parallel to the main axis of the brainstem and give rise to several lateral branches; these lie in close contact and interdigitate extensively, especially in the rostral third of the bulbopontine region. From the outer limits of I and E networks, a progressive increase of unit density levels was observed towards the core; it showed that inside both I and E populations, RRU aggregate into high density foci (HDF). Large HDF were found in the main body of each population. Smaller HDF were observed scattered throughout the medulla; I, and to a lesser extent E, HDF invade and surround sensory and motor nuclei and roots of the branchial nerves.
前文32的研究结果表明，延髓-脑桥呼吸相关单位（RRU）可根据其峰值放电频率与呼吸周期的关系分为4类：一类吸气性（I）和三类呼气性（E，早期、中期和晚期）。本文报告了对其空间分布的进一步研究。总共记录了26520个单位，分布在一个单位立方体矩阵中，其中约2000个位于延髓和脑桥范围内。在每个立方体中估计了呼吸和非呼吸单位的百分比及密度。单位分布的统计分析表明，在某些区域发现RRU的概率很高。在单独的立方体中发现I和E单位的概率很高，而将三种E类型中的一种与其他两种分开记录的概率并不高于随机概率。因此，在空间分析中仅可考虑两类，即I和E。应用于单位立方体中I和E单位密度数据的阈值技术显示了I和E群体的明确界限。对I和E网络外表面进行的计算机三维（3-D）重建显示，半个延髓系统由2个连续且不间断的柱体组成，从颈髓交界处向上延伸至呼吸调整系统。I群体的主体位于延髓脑桥区域的尾侧三分之一和背外侧部分，而E群体的主体位于中间三分之一的腹内侧位置。两者都有与脑干主轴平行的尾侧和头侧延伸，并产生几个侧支；这些侧支紧密接触并广泛交叉，尤其是在延髓脑桥区域的头侧三分之一。从I和E网络的外部边界向核心观察到单位密度水平逐渐增加；这表明在I和E群体内部，RRU聚集形成高密度灶（HDF）。在每个群体的主体中发现了大的HDF。在整个延髓中观察到较小的HDF分散分布；I的HDF以及程度较轻的E的HDF侵入并包围感觉和运动核以及鳃神经的根。
