Transplantation of cerebellar anlagen to hosts with genetic cerebellocortical atrophy

Summary Embryonic cerebellar grafts from genetically normal donors were implanted into the cerebellomedullary cistern of adult Purkinje cell degeneration (pcd) and weaver mutant mice, which are respectively characterized by the selective loss of Purkinje and granule cells. Grafts placed into both mutant recipients exhibited a layered cellular organization reminiscent of the normal cerebellar cortex. Molecular, Purkinje, and granule cell layers were identifiable. Grafted Purkinje cells displayed characteristic cytological features, such as hypolemmal cisterns in association with mitochondria in the perikaryon, and lamellar structures in their axons. The cytological features of granule cell somata in the grafts appeared similar to those of mature granule cells. Electron microscopic examination of the molecular layer of the grafts revealed the presence of parallel fibers, which were not oriented in a parallel fashion; axon terminals of such fibers were often presynaptic to dendritic spines. The number of parallel fibers was markedly reduced in grafts implanted into both mutants compared to the normal cerebellar cortex; however, this phenomenon is commonly seen in cerebellum in tissue culture and in cerebellar transplants into normal hosts. It is concluded, therefore, that the environment of the mutant hosts does not affect the survival of Purkinje or granule cells and that transplantation of solid cerebellar grafts in the neurological mutants studied does not seem to pose any apparent limitations beyond those inherent to the process of cerebellar growth and differentiation outside its normal environment.Dedicated to Herbert von Karajan     

Anterograde transsynaptic degeneration in the deep cerebellar nuclei of Purkinje cell degeneration (pcd) mutant mice

Summary The genetically-determined loss of Purkinje cells (PCs) in Purkinje cell degeneration (pcd) mutant mice results in the loss of presynaptic afferents to the deep cerebellar nuclei (DCN). This deafferentation takes place between postnatal day (P)17 and P45, i.e. after the maturation of cerebellar circuitry. We examined the DCN of normal and pcd mutant mice by quantitative light microscopic methods to determine whether neuronal atrophy or loss in the DCN take place during and after the loss of their input from the PCs. Neuronal diameters in control mice were 16.4±0.72 m (mean±S.D.) at P23 and 15.6±0.64 m at P300. The respective values in pcd mutant mice were 15.7±0.58 m and 13.5±0.24 m. Diameters in 300-day-old mutants were significantly smaller than those in both age-matched controls and 23-day-old mutants (P< 0.001). Neuronal populations in the DCN of control mice were 10,167± 949 at P23 and 10,429±728 at P300. The respective values in mutants were 9,436±1,366 and 7,424±1,324. There was a significant difference of 29% [95% confidence limits: 9–45%] between 300-day-old mutants and age-matched controls (P<0.01), and a significant loss of 21% [95% confidence limits: 4–36%] in 300-day-old mutants with respect to 23-day-old mutants (P<0.05). The total volume of the DCN was 22% less in 300-day-old mutants in relation to 23-day-old mutants (P< 0.05). These findings support the idea that the stability of DCN neurons in the mature cerebellum depends in part on the synaptic input from PCs.     

Ontogeny of GABA-immunoreactive cells in the primate cerebellar cortex: comparison with somatostatin-immunoreactivity

The distribution and ontogeny of GABA-immunoreactive cells were studied and compared with that of somatostatin-immunoreactivity in the primate cerebellar cortex. At embryonic day 80, we observed neither GABA-nor somatostatin-immunoreactive cells in the cerebellum. At embryonic day 110, a small number of GABA-immunoreactive cells was detectable in the granular layer only, and these cells seemed to be Golgi cells. At embryonic day 140, although almost all Purkinje cells were somatostatin-immunoreactive, a proportion of these cells was GABA-immunoreactive. At the newborn stage, most of the Purkinje cells were GABA-immunoreactive and almost all of them were also somatostatin-immunoreactive. During the postnatal stages, the number of somatostatin-immunoreactive cells decreased until postnatal day 60. At the adult stage, a large number of Purkinje cell bodies was faintly GABA-immunoreactive and a proportion of Purkinje cell dendrites was GABA-immunoreactive. In the aged animals (28 and 31 years old), a small number of Purkinje cell dendrites was GABA-immunoreactive. These findings suggest that a transition of phenotype from somatostatin to GABA occurred in Purkinje cells during development.Abbreviations Ad Adult - EX embryonic day X - GABA -aminobutyric acid - GAD glutamic acid decarboxylase - ir immunoreactive - Nb newborn (postnatal day 1–3) - NGF nerve growth factor - PX postnatal day X - PXy X years old - P8y < more than 8 years old - PBS phosphate-buffered saline - PL Purkinje cell layer - SOM somatostatin - WM white matter     

Immunohistochemical demonstration of regionally selective projections from locus coeruleus to the vestibular nuclei in rats

Summary This study describes a regionally selective projection of tyrosine hydroxylase and dopamine -hydroxylase-immunoreactive fibers from locus coeruleus (LC) and the A4 region of nucleus subcoeruleus to the vestibular nuclear complex in Long-Evans and Sprague-Dawley rats. These fibers travel in two distinct pathways. A lateral descending noradrenergic bundle provides input from LC to the superior vestibular nucleus (SVN), the cochlear nuclei, and the cerebellar cortex. A medial descending noradrenergic bundle provides input to the lateral vestibular nucleus (LVN), medial vestibular nucleus (MVN), and the inferior vestibular nucleus (IVN) before continuing on to the cochlear and cerebellar nuclei. The terminal plexus of these fibers varies markedly across these vestibular nuclear regions. Immunoreactive axons form a dense plexus around somata and proximal dendrites of Deiters' neurons in dorsal LVN. The axon plexus is less dense in SVN and ventral LVN, and relatively sparse in MVN and IVN. This regional selectivity of noradrenergic innervation suggests that central adrenergic systems may selectively modulate vestibulospinal reflexes at the level of the vestibular nuclear complex.     

“Exercise pyrogens”

Blood plasma taken from subjects either at rest or during muscular exercise was injected intravenously into rabbits. The rectal temperature of the animals changed differently: After injection of exercise plasma the temperature was at a higher level. This effect can be explained by the presence of exercise pyrogens in the plasma.Department of Physiology, Moscow Regional Institute of Physical Culture, Malakhova, Moscow Province. (Presented by Academician of the Academy of Medical Sciences of the USSR V. A. Negovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 8, pp. 144–145, August, 1979.     

The use of a retroviral vector to identify foetal striatal neurones transplanted into the adult striatum

Summary A retrovirus which encodes -galactosidase was used to infect embryonic rat striatal cells before grafting these cells into the lesioned adult rat striatum. Examination of the grafts after long term survival (8 months) revealed that a few small and large cells expressed large amounts of bacterial -galactosidase activity. The larger diameter cells were identified as neurones by their size, shape and presence of neuronal processes. The identity of the small diameter cell types was not established.     

Influence of saccadic eye movements on geniculostriate excitability in normal monkeys

Summary Using permanently implanted electrodes in squirrel monkeys and macaques, transmission through the lateral geniculate nucleus (LGN) was assayed from the amplitude of potentials evoked in optic radiation by an electrical pulse applied to optic tract. Averaging of either individually or machine selected potentials, elicited at 0.3, 1.0, 20 or 50 Hz, in all cases showed a decrease in transmission ranging from 5–60 % in the period after saccadic eye movements made ad libitum. The suppression was greater in a patterned visual environment than in diffuse illumination, which in turn was greater than that occurring following saccades in the dark. Demonstration of the effect in darkness always required data averaging and never exceeded 20%. The effect was consistently greater in the magnocellular than parvocellular component. Suppression was often abruptly terminated and replaced by a facilitation of 5–15% about 100 msec after saccade detection. Comparable effects were observed for excitability of striate cortex tested by a stimulus pulse applied to optic radiation. In addition, sharply demarcated potentials inherently arising in LGN and striate cortex were found in association with saccades made even in total darkness. Neglecting a possible but dubious contribution from eye muscle proprioceptors, the experiments establish the existence of a centrally originating modulation of visual processing at both LGN and striate cortex in relation to saccadic eye movement in primates. This modulation may partially underlie the phenomenon of saccadic suppression and hasten the acquisition of a meaningful visual sample immediately following an ocular saccade. It remains uncertain as to how it may relate to similar or greater effects accompanying changes in alertness, or to fluctuations of unknown origin occurring sometimes semirhythmically at 0.05–0.03 Hz (Fig. 7).Supported by Grant NS 03606 and Contract 70-2279 from the National Institutes of Neurological Diseases and Stroke, National Institutes of Health and by Grant GB 7522X from the National Science Foundation. B.B.L. was also aided by a travel grant from the Wellcome Trust (U.K.) and H.S. received a travel grant from the International Brain Research Organization.     

Human T-lymphocyte subset production of immune (γ) interferon

Human T, T, and T lymphocyte subpopulations have the capacity to respond to phytohemagglutinin (PHA)in vitro with proliferation and the production of a pH 2 and heat-labile interferon. This occurs both when the subsets are isolated by direct rosetting techniques or by negative selection. Macrophages enhance the production of the interferon by each lymphocyte subset and do not themselves produce interferon in response to products of PHA-activated lymphocyte subsets. Thus our studies indicate that subpopulations of T lymphocytes known to differ with regard to morphology, surface receptors, RNA content, response to corticosteroids and X-irradiation, and other functional capabilities do not differ with regard to their capacity to produce interferon.     

Effect of “flow anoxia” and “non flow anoxia” on the NAD/NADH redox state of the intact brain cortex of the cat

In the present study, we compared the nicotin-amide adenine dinucleotide (NAD) reducing potencies of flow anoxia and non flow anoxia in the cat brain cortex. In animals anaesthetized with alpha-D-glucochloralose flow anoxia and non flow anoxia were produced by ventilating for 2 and 25 min, respectively, with nitrogen gas. Following non flow anoxia, the brain cortices of dead animals were superfused with oxygen saturated artificial cerebrospinal fluid (mock CSF), and subsequently with CSF containing various concentrations (10^–3–10^–1 M) of potassium cyanide. NADH (reduced NAD) fluorescence of the brain cortex was measured through a cranial window with microscope fluororeflectometer. Ventilating the animals for 2 and 25 min with nitrogen gas increased cortical NADH fluorescence (NAD reduction) by 43.5±2.8% and 135.3±6.1%, respectively. Oxygen saturated CSF superfusion of the ischemic brain cortex restored the cortical NAD/NADH redox state to the preanocic level (oxidation of NADH). 10^–1 M cyanide, applied after superfusion of the brain cortex with oxygen saturated CSF resulted in comparable NAD reduction to that produced by non flow anoxia. On the basis of these findings it is suggested that non flow anoxia leads to much greater cortical NAD reduction than flow anoxia, because oxygen tension in the cortex may not fall to zero mm Hg during nitrogen anoxia lasting for 2 min. Besides this, a more pronounced substrate mobilization and acidosis may also contribute to the greater NAD reducing potency of non flow anoxia. Finally, since 10–15 min after the death of the animal the cerebral carbohydrate reserves are completely exhausted, and in our experiments non flow anoxia, reoxygenation of the ischemic brain cortex and inhibition of the cortical mitochondrial electron transport by cyanide (10^–1 M) resulted in comparable redox state changes (as far as their magnitude is concerned), it is concluded that the recorded changes in NADH fluorescence were of mitochondrial origin.     

Transplantation of embryonic retinal donor cells labelled with BrdU or carrying a genetic marker to adult retina

After transplantation of embryonic retinal cells to injured adult retina, it is often difficult to distinguish donor from host cells. To overcome this problem, two methods were applied: labelling donor cells with the nuclear marker bromodeoxyuridine (BrdU) and use of transgenic donor tissue. BrdU was injected into timedpregnant rats on 2 or 3 consecutive days. The donor embryos were taken 1–4 days later for transplantation. The BrdU-labelled donor tissue was examined in transplants sampled up to 1 year after grafting. Labelled donor cells were specifically identified in the transplants and in the interface with the adjacent host retina. The varying intensities of cell labelling indicated differences in the initial uptake of BrdU in the S-phase, or the dilution of the label by cell divisions after BrdU injection. The best labelled cells were presumably the ones that stopped dividing shortly after injection of BrdU. As controls, the normal development of BrdU-labelled retinas from the offspring of females that had been BrdU-injected at E16 and E17 and not used for transplantation was studied. Near the time of birth, clones of labelled cells were radially distributed. In the mature retina, labelled cells were seen in all retinal layers. Embryonic retina derived from transgenic (NSE-lacZ) mice was transplanted to nude, immunodeficient rats (xenografts). These transgenic mice contain the Escherichia coli -galactosidase gene, coupled to the promoter for neuron-specific enolase (NSE). Thus, all retinal donor cells that contain NSE could be identified by histochemistry or immunohistochemistry. The donor cells expressing the transgene could be detected several months after transplantation.     

Distant intercellular electromagnetic interaction between two tissue cultures

Experimental data on distant intercellular electromagnetic interaction between two tissue cultures when one of them is exposed to factors of biological (viruses) or chemical (mercuric chloride) nature are presented; the characteristic response of the intact culture is in the form of a mirror cytopathic effect.Laboratory of Biophysics, Institute of Clinical and Experimental Medicine, Siberian Branch, Academy of Medical Sciences of the USSR, Novosibirsk. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 3, pp. 337–339, March, 1980.     

Interferon β1a Treatment Modulates TH1 Expression in γδ + T Cells from Relapsing-Remitting Multiple Sclerosis Patients

A paradigm exists that multiple sclerosis is causally related to dysregulation of T_H1 inflammatory cytokines and T_H2 antiinflammatory cytokines. The cytokine source(s) that initiate the imbalances are unknown. In this study, , CD4, and CD8 T cell receptor-positive (TCR+) cells were isolated from the blood of 26 definitive relapsing-remitting multiple sclerosis patients prior to interferon -1a (IFN1a) therapy and following 8–10 weeks of this therapy. The bioactivities of interferon (IFN), interleukin 10 (IL10), and interleukin 12 (IL12) were determined. The concentrations of IFN, IL10, and IL12 from each cell type did not change significantly with IFN1a treatment. The IL10 secreted by TCR+ cells strongly correlated with the IL12 secreted by the same TCR+ cells, supporting the paradigm. Furthermore, IFN1a therapy decreased the TCR+ cell secretion of T_H1 cytokines after 8–10 weeks of therapy.     

Inverse behaviour of "synaptic" ribbon and spherule numbers in the pineal gland of male guinea-pigs exposed to continuous illumination

Summary There is increasing evidence that pineal synaptic ribbons are a heterogeneous population of organelles. In addition to synaptic ribbons (SR) sensu stricto, which consist of an electron-dense rod surrounded by electronlucent vesicles, synaptic spherules (SS) exist, the electrondense core of which is round and much wider than that of the SR. In the guinea-pig SR and SS numbers exhibit an inverse day/night rhythmicity. To gain more insight into the functional significance of SR and SS, guinea-pigs were exposed to continuous illumination for approximately 4 months (LL) and the respective structures in the pineal gland were quantitated under the electron microscope and compared with control animals kept under a lighting regiment of 12 h light and 12 h dark. It was found that SR numbers increase following LL whereas SS numbers decrease. The proximal, intermediate and distal parts of the dumbbell-shaped organ respond differently. The increase in SR numbers is significant in the distal and intermediate regions only, whereas the decrease in SS numbers is significant in the proximal and the intermediate regions only. Within each pineal region analyses of parenchymal subareas measuring 65 m by 65 m exhibit an inverse correlation of SR and SS numbers indicating that there are parenchymal domains in which either SR or SS predominate. Morphometric analyses of a number of pinealocytic parameters reveal minor differences between different pineal regions and that exposure to LL does not strikingly affect the pinealocyte perikarya. By contrast, the numbers of pinealocyte processes increase significantly after LL in the distal and intermediate, but not the proximal region of the pineal gland. These observations suggest structural and functional differences between different parts of the guinea-pig pineal gland.     

Endothelial cilia in human aortic atherosclerotic lesions

Summary Primary cilia were present in the endothelial cells of human aortic fatty dots and streaks but not in those of normal intima. They had the features of cilia of the 9+0 axonemal configuration observed in many other cells. A lateral foot process and transitional fibers anchored the ciliary basal body in the cytoplasm, but rootlets were not identified in material examined. Ladder-like configurations interconnected the two centrioles (=diplosome) of control endothelium.The primary cilia of endothelium differed from those of the rudimentary type observed in smooth muscle cells in similar lesions of man, but shared many features with cilia of those present in experimental atherosclerosis in rabbit.Cilia were rarely described in vascular endothelium. It is believed that, to date, they were not reported to occur in normal or pathological arteries in man.It is being stressed that whereas the significance of these unusual organelles remains uncertain, their widespread occurrence may indicate that their role is more important than was believed previously, and they should cease being a curiosity only.Presented-in-part at the Workshop of the American Heart Association: Evolution of the Human Atherosclerotic Plaque, Rockville, Maryland, September 20–23, 1986.Dedicated to Professor Dr. Gotthard Schettler, Department of Internal Medicine, University of Heidelberg, FRG, on the occasion of his 60 birthday (April, 1987).     

Role of adrenergic structures in functional control over the cerebral circulation

An investigation of the cerebral circulation by the thermoelectric method showed that stimulation of the cervical sympathetic nerve leads to considerable changes in the blood supply to the brain. The changes in blood flow are biphasic in character: An initial small increase is followed by a decrease below the original level. Pharmacological analysis with and adrenoblockers showed that the constrictor response of the cerebral vessels is due to excitation of-adrenergic structures and the dilator response to excitation of-adrenergic structures. A possible mechanism of these changes is postulated.Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 1, pp. 9–12, January, 1976.     

Synoviocytes in chronic synovitis in situ and cytokine stimulated synovial cells in vitro neo-express α1, α3 and α5 chains of β1 integrins

The expression of the 1 integrins was examined immunohistochemically in synoviocytes from normal synovial membrane and from chronic synovitis of different aetiology and intensity. Normal synoviocytes were 61-positive but lacked 1 through 5. In mild inflammation type A synoviocytes neo-expressed 1, 3, and 5 chains. In severe inflammation both type A and B synoviocytes expressed 3, 4, 5, and 6 chains. The effects of inflammatory cytokines, as single agents or in combination, on the 1 integrin expression in cultured normal synoviocytes was determined by immunocytochemistry and flow cytometry. The 1 chain, while absent in unstimulated synoviocytes, was induced by interleukin-1 (IL-1), tumour necrosis factor- (TNF-), and interferon- (INF-). This effect was enhanced by combining IL-1 and TNF-. Expression of the 3 chain was up-regulated by IL-1 and, more intensely, by IFN-. Transforming growth factor (TGF-) inhibited the up-regulating effect of IL-1 and antagonized the effect of IFN- on 3 chain expression. Expression of the 5 chain was up-regulated significantly by co-stimulation through IL-1 together with TGF- or TNF-. Thus, the 1 integrin profile of cytokine activated synoviocytes in vitro resembled that of synoviocytes in synovitis in situ. These data suggest that IL-1, TNF-, IFN-, and TGF- are likely to be among the effectors regulating 1 integrin expression in synoviocytes in vivo.     

The effects of the quality and probability of reinforcement on feeder selection by lobectomized dogs

The role of the prefrontal cortex was studied in an active selection situation in which dogs had to choose one of two feeders, with changes in the quality and probability of the reinforcement provided in one of the feeders. The study was performed in two stages. Before surgery, animals were trained to place themselves on a start area during the interstimulus interval. Dogs were presented with a conditioned stimulus for investigation of the sequence of selection of feeders with identical reinforcements. After bilateral extirpation of the prefrontal areas (the proreal gyrus), dogs continuously ran from one feeder to the other during the interstimulus period. In response to the conditioned stimulus, the animals repeated the reaction of selecting the same feeder on many occasions during the first few (7–9) days. When there was a conflict between the probability and quality of reinforcement, the dogs came to prefer the feeder with the greater reinforcement quality despite its lower probability of presentation. In our experiments, operated animals presented with food at probabilities of 30% and 100% performed feeder selections with different probabilities. One of the functions of the prefrontal cortex in intact animals would appear to be to support the reaction of selecting the greater probability of reinforcement.Translated from Zhurnal Vysshei Nervnoi Deyatelnosti, Vol. 54, No. 3, pp. 409–419, May–June, 2004.     

The in vivo inactivation of GABA and other inhibitory amino acids in the cat nervous system

Summary In cats anaesthetised with pentobarbitone, the effect of inhibitors of the in vitro cellular uptake of GABA were tested on the responses of single central neurones to GABA and other depressant amino acids. (+)- And (-)-nipecotic acid, (+)-2,4-diaminobutyric acid (DABA) and 2,2-dimethyl--alanine, enhanced the action of GABA on spinal, cerebellar and cerebral cortical neurones.In the spinal cord DABA, and to a less extent (-)-nipecotic acid, enhanced the action of -alanine, whereas the actions of glycine and taurine were unaffected by DABA and reduced by (-)-nipecotic acid. In the cerebellum and cerebral cortex, these two substances enhanced the action of GABA, usually to a greater extent than that of -alanine and taurine, although this specificity was not marked.The GABA-mediated basket cell inhibition of Purkinje cells in the cerebellum was unaffected by DABA and (-)-nipecotic acid, and neither substance appears suitable for determining the role of uptake processes in the inactivation of synaptically released GABA.Quantitatively these in vivo results agree more closely with recent in vitro uptake studies in cat tissue than the previously published data on rat cerebral cortex and dorsal root ganglia, and the observations provide further evidence for the importance of cellular uptake in maintaining low extraneuronal concentrations of inhibitory amino acid transmitters.     

Flow Cytometric Analysis of In Vitro Proinflammatory Cytokine Secretion in Peripheral Blood from Multiple Sclerosis Patients

The cytokines, interferon- (IFN-), tumor necrosis factor- (TNF-rpar;, and interleukin-2 (IL-2) are important endogenous proinflammatory proteins and have been linked to disease activity in multiple sclerosis. In this study, we use flow cytometric methodology to compare the secretion of IFN-, IL-2, and TNF- from peripheral blood-derived T cells of multiple sclerosis patients to the secretion in healthy controls. The percentages of IFN-, IL-2, and TNF- secreting cells are not significantly different between multiple sclerosis patients and controls. However, the TNF- secreting CDS cell percentage is correlated with the IFN- and IL-2 secreting CD3 cell percentages in multiple sclerosis patients. In the controls, only the TNF- secreting CD3 cell percentage is correlated with IFN-. These findings show that correlated secretion of cytokines occurs in multiple sclerosis and suggest that concerted intercytokine interactions may play an important role in the disease.     

Angiogenesis from mononuclear cells in thrombi

Summary In organizing thrombi angiogenesis is not dependent on invasion of vasa vasora from the vascular wall. Mononuclear cells of the monohistiocytic system are always present within the clotted blood and are capable of differentiation into various types of mesenchymal cells, including endothelial cells. At first autolytic slits and clefts appear in the fibrinous superficial areas of the thrombus. They are gradually lined by spindle-shaped pre-endothelial cells that already possess immunohistological properties of endothelial cells but still resemble primitive mesenchymal cells ultrastructurally. Later these cells gain connection with each other by pseudopodia, overlapping and interdigitation until the channels in the fibrinous matrix are covered by an uninterrupted layer of cells. These cells are now characterized ultrastructurally by the appearance of specific endothelial organelles (Weibel-Palade bodies). Circulation within these channels begins from the blood stream. In addition, angiogenesis by sprouting of vasa vasora from the vascular wall occurs in those areas of the thrombus in contact with the vessel wall. In blood vessels with on unimpaired intimal layer, angiogenesis by invasion of capillaries occurs at an earlier date than capillary formation by mononuclear cells.