Electrophysiological study of locus ceruleus projections to central cerebellar nuclei

Evoked response (field potentials) were recorded in all cerebellar nuclei when stimulating the locus ceruleus (LC). Response occurring in the dentate and fastigial nuclei were of considerably greater amplitude and were repeated at a higher rate than in the interstitial nucleus. Blockade of beta-adrenoreceptors led to clear-cut depression of response in the dentate and fastigial nuclei and increased response in the interstitial nucleus. Neuronal response to LC stimulation in the nuclei mainly took the form of inhibition of spontaneous discharges. A less pronounced response was observed in the interstitial nucleus. The findings obtained would indicate the presence of noradrenergic afferents reaching the cerebellar nuclei, where they are unevenly distributed.Kh. Anovyan Pedagogical Institute, Armenia SSR, Erevan. L. A. Orbeli Institute of Physiology, Academy of Sciences of the Armenian SSR, Erevan. Translated from Neirofiziologiya, Vol. 1, pp. 39–44, January–February, 1989.     

Morphometric study of the human muscle spindle

OBJECTIVE: To study the morphometric characteristics of the human muscle spindle in normal muscle and to investigate the influence of aging. STUDY DESIGN: The following variables were studied in 72 spindles: area and diameter of the spindle; thickness of the capsule; number, area and diameter of fibers; and number and area of nuclei. RESULTS: In deltoid and extensor digitorum brevis muscles, a reduction in the diameter of the spindle as a function of age was found, while no statistically significant change in the variables as a function of age was observed in the quadriceps femoris and biceps muscles. In the deltoid, a reduction in the number of fibers and an increase in their diameter were also observed. CONCLUSION: These findings could prove useful in the study of the spindle in relation to disease.     

Immunohistochemical study of structural basis of inhibition in central cerebellar nuclei

Glutamatic acid decarboxylase (GAD): a synthetic enzyme for inhibitory neurotransmitter GABA, was studied in the central cerebellar nuclei. Synapses were found: morphological structures providing of inhibition in the central cerebellar nuclei.     

Morphometric analysis of dendritic tree of cerebellar Purkinje-cells

Basic neural processes of sensorimotor adaptation can be observed by cellular-level studies on cerebellar cortex, both by electrophysiological and morphological means. In earlier studies we demonstrated double (sometimes triple or quadruple) rhythmic prespike activity patterns in dendritic microelectrode records taken from cerebellar Pc. By their active and passive interactions, the actual input pattern will turn into an arrhythmic output spiking, realizing a nonlinear and phase-sensitive integration. This curious complex spike-generating process can give rise to novel cerebellar functional models. The acting membrane dynamics rely not just upon the ionic current machinery but also upon the specific micromorphology of the dendritic tree, especially that of the branching areas. Although, statistical analyses on Pc dendrites generally followed the graph-theory, elaborated abstract parameters for complexity and hierarchy, and denied realistic geometry. Thus a novel specific morphometric study should be carried out, first applied to the main branching sites.     

Morphometric characterization of nuclei in non-Hodgkin's malignant lymphoma

In addition to the nuclear area and a form factor, four morphometric parameters of nuclear shape (ID, R1, R2 and ND), obtained by the application of the principles of mathematical morphology, were used to characterize the nuclear contours in non-Hodgkin's malignant lymphomas. The values for each parameter were determined in 58 cases of non-Hodgkin's lymphoma categorized according to the Kiel and National Cancer Institute classifications. Small-cell, mixed and large-cell lymphomas could be distinguished on the basis of the mean nuclear area. The shape parameters R1, R2 and ID were efficient discriminators of the large centrocytic (cleaved-cell) lymphomas. Neither size nor shape factors could distinguish between centroblastic and immunoblastic tumors. The good correlation between the morphometric findings and the histopathologic categories suggest that morphometry may provide a quantitative and objective method for grading lymphomas.     

Morphometric and topologic analysis of freeze-fractured interphase nuclei

Interphase rat liver nuclei were studied by freeze fracturing followed by electron microscopic observations. This method permits information on the native organization of the nuclear components in the hydrated state to be obtained. Morphometric analyses, performed with a Leitz Texture Analysis System, gave precise information on the different nuclear components, based on the histograms of their size distribution in heterochromatin, interchromatin and nucleolar areas. The textural characteristics were analyzed by computer to determine the topologic distribution of the solenoid chromatin fibers, the nucleosome filaments and the ribonucleoproteins in the different nuclear domains.     

Morphometric affinities of the human shoulder.

A recent discussion by Corruccini and Ciochon ('76) implies that previous multivariate morphometric studies of the shoulder, reviewed in Oxnard ('73), have been misinterpreted because due allowance was not made for the overall sizes of the specimens. Results that were given functional significance in the earlier investigations are cited as being due at least in part to overall bodily size. Although examination of the range of genera selected for mention by corruccini and Ciochon seems superficially to support this view, it is demonstrated here that examination of the full range of genera in the earlier studies refutes, unequivocally, that suggestion. The discussion by Corruccini and Ciochon ('76) also implies that the more complex size correction applied in their study produces a result different from that of the previous workers. Again, although perusal of the particular part of the earlier study selected for discussion by Corruccini and Ciochon would appear to bear that out, it is demonstrated here that comparisons with all parts of the earlier results provide a different picture. Thus the main result of Corruccini and Ciochon replicates rather closely a more restricted part of the earlier result not mentioned by Corruccini and Ciochon. The difference between Corruccini and Ciochon's principal result and the main result of the prior authors is shown to rest upon the difference between the more restricted earlier study of "residual" shoulder dimensions and the other broader studies; i.e., not upon any multivariate manipulation, but upon the inclusion in the broader study of a wider range of information about the shape of the primate shoulder. Knowledge of these and other points is important in assessing the overall contribution of the discussion of Corruccini and Ciochon.     

Constancy and variability in the content of DNA in cerebellar Purkinje cell nuclei. A cytophotometric study.

A cytophotometric study of DNA content in Purkinje cells of the cerebellum of rats, cats, chicken and humans (Feulgen staining) revealed that in a certain number of cells the amount of NDA ranged between the diploid and tetraploid level (H2C cells). The incidence of H2C Purkinje cells varied among the species studied. In rats, which were studied most thoroughly, these cells amounted on average to 3%. In some rats, as well as in some cats and chickens H2C Purkinje cells were entirely absent. In the group of animals possesing H2C Purkinje cells, great interindividual differences were observed. In rats for instance, the incidence of these cells varied from 1 to 23 per cent. Topographic analyses carried out in rat and human cerebellum revealed that H2C Purkinje cells occurred more frequently in the hemispheres than in the vermis. No significant differences were found in the number of H2C Purkinje cells in healthy and Kilham-DNA-virus infected rats. Densitometric analysis of the distribution of nuclear chromatin showed that H2C Purkinje cells were richer in condensed chromatin, especially in the region of the nucleolus, which apparently contains the hyperploid surplus of DNA. It is proposed that the phenomenon of DNA hyperdiploidy arises as a result of either incomplete S-phase in some immature Purkinje cell precursors or the amplification of some DNA sequences particularly those localized in the nucleolar region.     

Volume comparisons in the cerebellar complex of primates. II. Cerebellar nuclei

Volumes of medial, interposed, and lateral cerebellar nuclei (MCN, ICN, and LCN) were measured in Insectivora, Scandentia, and Primates, including man. The relative size of the nuclei was expressed in size indices. Insectivora had by far the smallest cerebellar nuclei. The simians, in general, had larger cerebellar nuclei than the prosimians, but there was considerable overlap. From Insectivora to man, the MCN was the least progressive and the LCN the most progressive. The indices are expected to reflect the relative size of the three longitudinal zones of the cerebellum (vermis/MCN, pars intermedius/ICN, hemisphere/LCN). They, together with those of the ventral pons and cerebellum (part I), are discussed in relation to the predominant locomotor pattern of a species, and with reference to evolutionary trends in primate phylogeny.     

Morphometric study of human alveolar ducts based on serial sections

Interactive computerized morphometry was used for the quantitative study of the terminal airway branches (alveolar ducts) that followed the last bronchioles in three human acini. Two normal adult human lungs from the autopsy service were fixed by instillation and serial sections were prepared; three tissues blocks showing a central bronchiole were selected. Primary and secondary alveolar walls were traced and the following parameters were measured: volume, surface area (of primary and secondary septa), curvature (in equivalent radius) for branches of individual generations, and cumulative values starting with the first alveolar duct and moving peripherally. Although branching was dichotomous, we noticed considerable asymmetry in the pattern of branching and number of side branches. The branching trees of alveolar ducts that we studied comprised 6,7, and 10 generations. The average volume of ducts was 0.04-0.13 mm3, the surface area of primary walls ranged from 0.3616 to 0.7931 mm2 and of secondary septal walls from 0.0100 to 0.0647 mm2. The equivalent radius of curvature was between 22.7 and 38.1 microns. Cumulative increases of volume and surface area revealed similarity in the first five generations. Secondary walls represented only 4% (or 8% if 2 sides are considered) of the primary surface area, strengthening the view that alveoli are incompletely developed side chambers secondary to the alveolar ducts.     

Morphometric estimation of growth of cell nuclei from plane section

In biological histology, cell size is measured from two-dimensional cell sections. The profile radii are recorded as a histogram. The estimation of real size distribution from the profile radius is Wicksell's corpuscle problem. Several approximate solutions of the integral equations have been discussed in the field of stereology. Cell size distribution can be used in the differential diagnosis between normal cells and malignant cells. In this study, we considered the estimation of cell growth rate from cell nuclei size distribution by methods analogous to those applied to life time analysis. The performance of estimates was investigated using a simulation study. Comparisons of performance between the estimates obtained for the profile radius and that for the radius obtained by estimated real size distribution are also made.     

小脑间位核对淋巴细胞功能的调节作用

目的:研究小脑深部核团之一间位核对淋巴细胞功能的调节作用,以拓宽对小脑功能的认识进而增加神经免疫学的知识.方法:在大鼠双侧小脑间位核内注射海人酸(KA)以损毁间位核内神经元的胞体,并设对照组,于小脑间位核内注入等量生理盐水.在手术后的第8、16、32 d分别用血细胞计数法检测动物外周血中淋巴细胞的数量;用四甲基偶氮唑(MTT)比色法检测动物肠系膜淋巴结细胞对刀豆蛋白A(Con A)刺激的增殖反应;用ELISA法检测动物血清中抗绵羊红细胞(SRBC)特异性IgM抗体的生成能力;用流式细胞术测定脾脏自然杀伤(NK)细胞的活性.结果:小脑间位核损毁后的第8、16、32 d,动物外周血中淋巴细胞数都明显低于损毁手术前的淋巴细胞数,也显著低于生理盐水对照组相应时间段的淋巴细胞数.在小脑间位核注射KA后的第8、16、32 d,动物的肠系膜淋巴结细胞由Con A诱导的增殖反应、血清中特异性抗SRBC IgM抗体的生成能力和脾脏NK细胞杀伤靶细胞YAC-1的活性均明显低于生理盐水对照组,但比较损毁后不同时间段的T、B和NK细胞功能的变化,没有发现显著的差异.结论:小脑双侧间位核损毁可导致总淋巴细胞数以及T、B和NK细胞功能均发生不可逆的降低,充分说明小脑间位核可调节淋巴细胞的功能,并提示在正常体内,小脑间位核对淋巴细胞功能具有增强效应.     

Projections of the central cerebellar nuclei to the intralaminar thalamic nuclei in cats

Projections of the central cerebellar nuclei to the intralaminar thalamic nuclei were studied in cats with the use of light and electron microscopy. Almost all intralaminar nuclei were shown to obtain cerebello-thalamic projections. The entire complex of the central cerebellar nuclei serves as a source of such projections; yet, involvement of different nuclei is dissimilar. Destruction of the central and, especially, caudal regions of the fastigial nucleus evoked in the intralaminar thalamic nuclei degenerative changes in the nerve fibers (from swelling and development of varicosities up to total fragmentation). Pathological phenomena could be noticed in the most caudal regions of the above thalamic nuclear group, including the medial dorsal nucleus. Projections of the cerebellar interpositus nucleus were directed toward nearly the same regions of the intralaminar nuclei; degeneration was more intensive (covered thecentrum medianum) when posterior regions of the interpositus nucleus were destroyed. Destruction of the lateral cerebellar nucleus evoked a similar pattern of pathological changes, but degeneration was also observed in some structures of the ventral and anterior nuclear groups of the thalamus. Electron microscopic examination showed that degeneration of dark and light types developed in the fiber preterminals and terminals. It can be concluded that the central cerebellar nuclei project not only to the ventral complex of the thalamic nuclei, but also to the anterior, medial, and intralaminar nuclear groups (rostral and caudal portions).