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Messer A, Maskin P, Snodgrass GL. Effects of triiodothyronine (T3) on the development of rat cerebellar cells in culture. Int J Dev Neurosci 2003; 2:277-85. [DOI: 10.1016/0736-5748(84)90022-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/1984] [Indexed: 11/29/2022] Open
Affiliation(s)
- Anne Messer
- Center for Laboratories and Research; New York State Department of Health; Albany NY 12201 U.S.A
| | - Paul Maskin
- Center for Laboratories and Research; New York State Department of Health; Albany NY 12201 U.S.A
| | - Gary L. Snodgrass
- Center for Laboratories and Research; New York State Department of Health; Albany NY 12201 U.S.A
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McMorris FA, McKinnon RD. Regulation of oligodendrocyte development and CNS myelination by growth factors: prospects for therapy of demyelinating disease. Brain Pathol 1996; 6:313-29. [PMID: 8864287 DOI: 10.1111/j.1750-3639.1996.tb00858.x] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Multiple sclerosis (MS), the most common neurological disorder diagnosed in young adults, is characterized by autoimmune demyelination in the central nervous system (CNS). Promotion of remyelination in the brain and spinal cord is a potential strategy for therapeutic intervention in MS and other demyelinating diseases. Recent studies have shown that the development of oligodendrocytes, the myelin-forming cells of the CNS, is extensively controlled by growth factors. These factors regulate the proliferation, migration, differentiation, survival and regeneration of oligodendroglial cells and the synthesis of myelin, and often interact in a complex manner. Moreover, insulin-like growth factor I (IGF-I) has proven effective for therapy of experimental autoimmune encephalomyelitis (EAE), an animal model of autoimmune demyelination. In this review we summarize recent findings on the regulation of oligodendrocyte development and CNS myelination by growth factors, and discuss these findings in the context of possible clinical application for the therapy of neurological disease in humans.
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Affiliation(s)
- F A McMorris
- Wistar Institute, Philadelphia PA 19104-4268, USA.
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3
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Arai O, Saito N. Thyroxine reduces the production rate of BrdU-labeled cells in the ventricular zone of the adult canary brain. Neurosci Lett 1995; 198:135-8. [PMID: 8592639 DOI: 10.1016/0304-3940(95)11989-a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
When the canary reaches adulthood, neuron production continues in the lateral ventricular zone (VZ) of the forebrain. The effect of thyroxine injection on the cell production rate in the VZ during adulthood was studied immunohistochemically using bromodeoxyuridine (BrdU). The rate of occurrence of BrdU-labeled cells was reduced by thyroxine injection (1 mg/body). Hyperthyroidism usually promotes increased mitotic activity, but in the present study this was not the case. The decrease in the number of BrdU-labeled cells in the VZ appears to have resulted from premature termination of cell proliferation due to early initiation of cell differentiation. Our results suggest that the production rate of cells in the VZ of the adult canary changes seasonally, decreasing in the summer when the plasma level of thyroxine increases.
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Affiliation(s)
- O Arai
- Department of Physiology, Dokkyo University School of Medicine, Tochigi, Japan
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4
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Schmitt CA, McDonough AA. Thyroid hormone regulates alpha and alpha + isoforms of Na,K-ATPase during development in neonatal rat brain. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(19)77885-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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5
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Affiliation(s)
- T Noguchi
- Department of Physiology, Toho University School of Medicine, Tokyo, Japan
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Pereira de Vasconcelos A, Nehlig A. Effects of early chronic phenobarbital treatment on the maturation of energy metabolism in the developing rat brain. I. Incorporation of glucose carbon into amino acids. Brain Res 1987; 433:219-29. [PMID: 3690333 DOI: 10.1016/0165-3806(87)90025-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The influence of phenobarbital (PhB) on the utilization of glucose by the cerebral cortex and the cerebellum was studied in rats during postnatal development. The animals were treated from day 2 to day 35 after birth by a daily injection of 50 mg/kg PhB or by saline. The rats were studied at 5 postnatal stages: 7, 10, 14, 21 and 35 days. PhB treatment induced a 10% decrease in body and brain weight over the whole period studied and a transient significant decrease in circulating thyroxin levels at 14 days after birth. Amino acid levels in the cerebral cortex and particularly in the cerebellum were not greatly affected by the pharmacological treatment. The conversion of [2-14C]glucose into amino acids was significantly decreased in both cerebral structures between day 7 and day 14 after birth. The distribution of radioactivity between amino acids was not affected in the cerebral cortex but was significantly changed by PhB treatment in the cerebellum. Specific radioactivity values of amino acids were lower in PhB- than in saline-treated animals in both studied structures. The results of the present study show that glucose utilization is reduced in the brain of PhB-treated animals as compared to the controls and that the cerebellum seems to be more affected than the cerebral cortex.
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7
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Sato T, Ishiguro C, Watanabe Y, Mizukoshi K. Quantitative analysis of cerebello-vestibular function in congenital hypothyroidism. ACTA PAEDIATRICA JAPONICA : OVERSEAS EDITION 1987; 29:121-9. [PMID: 3144836 DOI: 10.1111/j.1442-200x.1987.tb00019.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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8
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Li JQ, Wang X, Yan YQ, Wang KW, Qin DK, Xin ZF, Wei J. The effects on fetal brain development in the rat of a severely iodine deficient diet derived from an endemic area: observations on the first generation. Neuropathol Appl Neurobiol 1986; 12:261-76. [PMID: 3736774 DOI: 10.1111/j.1365-2990.1986.tb00139.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Rats were fed on a severely iodine deficient diet (iodine content 4.5 micrograms/100 g) similar to that being consumed by people living in a village with a high rate of endemic cretinism. After a period of 4 months, the thyroid and brain were studied in the adult and their fetuses at 16, 17, 18, 19 and 20 days of gestation, and in postnatal animals at 1, 5, 10, 20, 30 and 60 days of age. By comparison with a control group (diet with iodine content 54.7 micrograms/100 g) the experimental group showed marked goitres, a higher uptake of 125I by the thyroid, reduced serum T4, and reduction in brain weight. The cerebral and cerebellar histological findings showed that the density of brain cells had increased, and the mean neuron size was reduced. Furthermore, disappearance of the cerebellar EGL was delayed. These findings indicate that this animal model is likely to be suitable for the studies of endemic cretinism in man.
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9
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Noguchi T, Sugisaki T, Satoh I, Kudo M. Partial restoration of cerebral myelination of the congenitally hypothyroid mouse by parenteral or breast milk administration of thyroxine. J Neurochem 1985; 45:1419-26. [PMID: 4045455 DOI: 10.1111/j.1471-4159.1985.tb07208.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We attempted to define whether thyroid hormone can ameliorate the cerebral hypomyelination present in the congenitally hypothyroid (hyt) neonatal mouse, and to define the critical time period during early postnatal life when thyroxine (T4) is essential for myelin formation. We administered T4 to the hyt mouse by breast milk during the first 20 days of postnatal life, and through the diet during the second 20 days of postnatal life. Positive results were obtained only when hormone was given during the first 20 days of postnatal life. A distinct increase in cerebral 2',3'-cyclic nucleotide 3'-phosphohydrolase activity was noted, and brain sections stained for myelin basic protein correlated with the biochemical findings. The later administration of hormone through diet was ineffective.
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10
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Romijn HJ, van Huizen F, Wolters PS. Towards an improved serum-free, chemically defined medium for long-term culturing of cerebral cortex tissue. Neurosci Biobehav Rev 1984; 8:301-34. [PMID: 6504415 DOI: 10.1016/0149-7634(84)90055-1] [Citation(s) in RCA: 182] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The present study describes a series of experiments which have led to a substantially improved serum-free, chemically defined medium (CDM) for long-term culturing of reaggregated fetal rat cerebral cortex tissue. A reduction of the original medium concentrations of the hormones insuline, T3 and corticosterone, on the one hand, and an enrichment of the medium with the vitamins A, C and E, the unsaturated fatty acids linoleic and linolenic acid, and biotin, L-carnitine, D(+)-galactose, glutathione (reduced) and ethanolamine, on the other hand, formed the most important chemical adjustments of the medium. With the aid of this CDM (encoded R12), the light- and electron microscopic architecture of the tissue could be kept in a good condition (superior to that seen earlier in serum-supplemented medium) up to 23 days in vitro. From that time on, the neuronal network lying between the reaggregates degenerated for the largest part, while a portion of the large neurons (probably pyramidal cells) plus some of the neuronal network within the reaggregates degenerated too. This degeneration process continued during the following weeks, but the reaggregates nevertheless retained most of their mass, so that both small and large neuronal cell bodies (visible in transparent regions at the edge of the reaggregates) remained in good condition up to at least 103 DIV. Stout, thick nerve bundles interconnecting the reaggregates, also survived up to this point. Electron microscopic evaluation of such 'aged' reaggregates revealed degenerating as well as healthy regions. The latter had indeed retained healthy-looking pyramidal and non-pyramidal neurons, embedded within a dense neuropil which was often traversed by myelinated axons. The numerical synapse density in such selected, healthy tissue regions reached its maximum during the sixth week in vitro, followed by a rapid decrease and a stabilization at about half the peak values. The present culture system has opened the possibility for performing controlled quantitative studies on the relationship between structure and function of cerebral cortex tissues during development and aging, on its dependence on nutrients, hormones and drugs, and on special factors synthesized by the tissue and released into the nutrient medium.
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11
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Eccleston PA, Silberberg DH. The differentiation of oligodendrocytes in a serum-free hormone-supplemented medium. Brain Res 1984; 318:1-9. [PMID: 6386106 DOI: 10.1016/0165-3806(84)90056-7] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Primary mixed cultures of trypsin-dissociated fetal and newborn rat brain and spinal cord have been grown in a serum-free medium. This medium, containing insulin, selenium, transferrin and triiodothyronine, was optimized for oligodendrocyte survival by determining the number of cells which expressed surface galactocerebroside. Comparison of cultures in serum-containing and serum-free media revealed that galactocerebroside positive (GalC+) oligodendrocytes could be detected earlier in the absence of serum. This early differentiation occurred in the absence of the added hormones and nutrients, whose main function appeared to be to prolong survival of the cells. The effect of serum on the differentiation of oligodendrocytes was studied by comparing the expression of surface GalC in media containing 2.5% or 10% fetal calf serum. At a given time a much greater number of GalC+ oligodendrocytes could be detected at the lower serum concentration. However, when cultures were transferred from 10% serum to serum-free medium (or 1% serum) large numbers of GalC+ oligodendrocytes subsequently appeared, showing that precursors were present in the high-serum medium, but that they were unable to differentiate. Possible explanations of the effect of serum on oligodendrocyte differentiation are discussed.
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12
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Noguchi T, Sugisaki T, Tsukada Y. Stimulation ofSnell dwarf mouse neuronal growth by GH and T4. ACTA ACUST UNITED AC 1984; 2:123-38. [PMID: 6544386 DOI: 10.1007/bf02834251] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
An investigation of the Snell dwarf motor cortex, area 6 of Caviness, was carried out by means of a modified Golgi silver impregnation method. The pyramidal neurons located in layer V were found to have small perikarya, short primary dendrites with sparse branchings. Following administration of bovine growth hormone (bGH) and thyroxine (T4) during the first 20 d of postnatal life, this retarded neuronal growth was restored to normal: neuronal perikarya were enlarged, and the dentrites were thicker with denser branchings. These results were confirmed in the sections stained for neuron specific enolase (NSE). These findings demonstrate that exogenous GH and T4, will enhance neuronal growth in the Snell dwarf cerebrum, and restore neuronal arborization to normal.
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13
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Noguchi T, Sekiguchi M, Sugisaki T, Tsukada Y, Shimai K. Faulty development of cortical neurons in the Snell dwarf cerebrum. Brain Res 1983; 312:125-38. [PMID: 6197143 DOI: 10.1016/0165-3806(83)90127-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
In the Snell dwarf motor cortex, area 6 of Caviness, the cell number, the stratification of neurons and the portion of layer-widths were absolutely identical to those of the controls. By means of the Golgi-Cox method modified by Ramon-Moliner, however, the pyramidal neuron was found to have small perikarya, short primary dendrites with sparse branchings, and a low spine density on the dendrites. The corpus callosum of the dwarf contained a reduced number of fibers compared to that of the controls, and the staining for myelin basic protein revealed a considerable reduction of positive-fibers of radiation in this area. The content of Thy-1 antigen in the cerebrum, cerebellum and brainstem, was significantly lower than that of controls, but the monoamine content was normal in the cerebrum and brainstem. From these results, it appears that the Snell dwarf cerebrum shows retarded neuronal growth; a reduction in size of neurons, an underdevelopment of axons and dendrites, and a retarded maturation of spine, in addition to arrested glial proliferation. At present, it is unclear which hormone deficient in these mutants, growth hormone or thyroxine, is the essential potentiator for neuronal growth.
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14
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Fishman RH, Gaathon A, Yanai J. Early barbiturate treatment eliminates peak serum thyroxine levels in neonatal mice and produces ultrastructural damage in the brains of adults. Brain Res 1982; 281:202-5. [PMID: 7139349 DOI: 10.1016/0165-3806(82)90158-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Serum thyroxine levels peak sharply at the end of the second postnatal week in mice. Treating neonatal mice with barbiturates (PhB) completely eliminates this marked thyroxine (T4) peak without significantly affecting nonpeak levels at other ages. PhB treatment at this same time also establishes or induces long-lasting degenerative processes that continue to result in ultrastructural neural deficits in adults, long after treatment has been discontinued. Similar neural deficits have been observed in animals which were deficient in T4 during this same period of development.
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15
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Noguchi T, Sugisaki T, Tsukada Y. Postnatal action of growth and thyroid hormones on the retarded cerebral myelinogenesis of Snell dwarf mice (dw). J Neurochem 1982; 38:257-63. [PMID: 6286878 DOI: 10.1111/j.1471-4159.1982.tb10878.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Snell dwarf mice (dw) showed a lower CNPase activity (59% of the normal controls) only in the cerebrum among different parts of the CNS, and a strikingly reduced level of spontaneous locomotion activity with an indistinct diurnal periodicity in a 24-h record at 40 days of age. Daily administration of bGH and T4 to the dwarfs during the first 40 days of postnatal life restored CNPase activity to the level of the normal controls, and was accompanied by normalization of the pattern of spontaneous locomotion activity. Daily administration of bGH alone also restored CNPase activity and spontaneous locomotion, but to a lesser extent. The daily administration of thyroid stimulating hormone (TSH) alone, however, failed to restore CNPase activity, in spite of the fact that the thyroid glands of the TSH-treated dwarfs were indistinguishable from the normal controls in organization and appearance. These results indicate that the restoration of both the retarded myelinogenesis and abnormal behavior of the Snell dwarf mice might essentially depend upon GH levels and the synergistic effects of T4.
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16
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17
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Bhat N, Rao G, Pieringer R. Investigations on myelination in vitro. Regulation of sulfolipid synthesis by thyroid hormone in cultures of dissociated brain cells from embryonic mice. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)69944-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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18
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Johanson IB. Development of olfactory and thermal responsiveness in hypothyroid and hyperthyroid rat pups. Dev Psychobiol 1980; 13:343-41. [PMID: 7380106 DOI: 10.1002/dev.420130309] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Hypo- and hyperthyroid rat pups were tested for their responsiveness on an olfactory and a thermal gradient in an attempt to evaluate the effects of perinatal thyroid manipulation on the ability of the pups to use these cues in orientation. Hypothyroid pups showed a delay and hyperthyroid pups an acceleration in the development of orientation along the olfactory gradient, relative to controls. None of the pups was able to utilize a thermal gradient in directed orientation but pups moved less at the warm end of the gradient than at the cool end. This differential responsiveness was strongest in the hypothyroid pups, suggesting that these pups could utilize thermal cues in an orthokinetic orientation.
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19
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Cullen MJ, Webster HD. Remodelling of optic nerve myelin sheaths and axons during metamorphosis in Xenopus laevis. J Comp Neurol 1979; 184:353-62. [PMID: 762287 DOI: 10.1002/cne.901840209] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Whole mounts and transverse sections of Xenopus optic nerves were examined with the light and electron microscopes before, during, and after metamorphosis. In stage 52--58 tadpoles, almost all myelin sheaths were circular in transverse sections. Early in metamorphosis (stages 60--61) large redundant myelin loops surrounded many large axons in central regions of the nerve. The loops subsequently were broken down into ovoids and lamellar segments that remained mostly within oligodendrocytes. These myelin changes were not observed in the chiasm or next to the eye. They were not associated with significant axonal degeneration and were no longer apparent in optic nerves of young frogs. Xenopus optic nerves also became shorter during metamorphosis. We therefore suggest that myelin sheaths with redundant loops which degenerate and disappear are being remodelled as the nerve decreases in length.
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20
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Schwartz HL, Oppenheimer JH. Physiologic and biochemical actions of thyroid hormone. PHARMACOLOGY & THERAPEUTICS. PART B: GENERAL & SYSTEMATIC PHARMACOLOGY 1978; 3:349-76. [PMID: 203955 DOI: 10.1016/s0306-039x(78)80002-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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21
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Weimar WR, Neims AH. The effects of postnatal hyper- and hypothyroidism on the development of D-amino acid oxidase in rat cerebellum and brain stem. Brain Res 1977; 138:139-50. [PMID: 22391 DOI: 10.1016/0006-8993(77)90789-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Treatment of rats with propylthiouracil for the first 30 days of postnatal life drastically retards the ontogenesis of D-amino acid oxidase in the brain stem and cerebellum. There is a marked terminal deficit of D-AAO in both the brain stem (--64%) and cerebellum (--67%) at 94 days (adults) despite the near euthyroid status at this age. If initiated early enough, thyroxine replacement therapy reverses the effects of PTU on the development of D-AAO. Hyperthyroidism significantly accelerates the development of D-AAO in both brain stem and cerebellum. Nonetheless, animals treated with thyroxine the first month of life display a net deficit of cerebellar D-AAO content in adulthood. The results are discussed in terms of the localization of D-AAO in cell types especially sensitive to thyroid hormone: (1) a cell type which is among the last to derive from the external germinal zone in the developing cerebellum, and which in the adult is located adjacent to the Purkinje cell soma; and (2) mossy fiber neurons and cerebellar glomeruli.
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22
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Druse MJ, Hofteig JH. The effect of chronic maternal alcohol consumption on the development of central nervous system myelin subfractions in rat offspring. Drug Alcohol Depend 1977; 2:421-9. [PMID: 562252 DOI: 10.1016/0376-8716(77)90043-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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23
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Effects of altered thyroid function on galactosyl diacylglycerol metabolism in myelinating rat brain. J Biol Chem 1977. [DOI: 10.1016/s0021-9258(17)40103-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Murad S, Strycharz GD, Kishimoto Y. Alpha-Hydroxylation of lignoceric and nervonic acids in the brain. Effects of altered thyroid function on postnatal development of the hydroxylase activity. J Biol Chem 1976. [DOI: 10.1016/s0021-9258(17)33152-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Patel AJ, Rabié A, Lewis PD, Balázs R. Effect of thyroid deficiency on postnatal cell formation in the rat brain: a biochemical investigation. Brain Res 1976; 104:33-48. [PMID: 1247907 DOI: 10.1016/0006-8993(76)90645-4] [Citation(s) in RCA: 89] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In thyroid deficiency, interference with postnatal cell formation seems to be confined to those regions of the brain where postnatal neurogenesis is significant. In comparison with controls the increase in cell number in the cerebellum is retarded in the second week of life, but a normal number is reached by 35 days. In contrast the DNA content of the olfactory bulbs is apparently irreversibly depressed. Mitotic activity, in terms of incorporation of [2-14C]thymidine into DNA, is mainly affected in the cerebellum: in thyroid deficient rats, it is depressed below control levels at day 12, but it is about 4 times higher than in controls at day 21 when, under normal conditions, cell proliferation has virtually ceased. The time course (15-240 min) of [14C]thymidine metabolism at day 14 shows regional differences in control rats. The rate of conversion of [14C]thymidine to [14C]thymidine nucleotides, and of these in turn to [14C]DNA is slower in the forebrain - where cell proliferation occurs on a smaller scale - than in the cerebellum. Consequently, in the forebrain nearly linear DNA synthesis rate is maintained for a longer time than in the cerebellum (1 h vs. 0.5 h), and since less 14C is conserved in DNA a significant efflux of unconverted [14C]thymidine is evident during the experimental period. The effect of thyroid deficiency on [14C]thymidine metabolism in the brain is only slight, and is due to an abnormally large supply of [14C]thymidine consequent to depressed systemic utilization of this precursor.
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Lewis PD, Patel AJ, Johnson AL, Balázs R. Effect of thyroid deficiency on cell acquistion in the postnatal rat brain: a quantitative histological study. Brain Res 1976; 104:49-62. [PMID: 1247908 DOI: 10.1016/0006-8993(76)90646-6] [Citation(s) in RCA: 100] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The mechanisms underlying transient reduction of cell number in the developing cerebellum of thyroid-deficient rats have been studied by quantitative histological methods. Thyroid deficiency has no significant effect on the generation cycle of dividing cells in either the subependymal layer of the lateral ventricular walls or the external granulay layer of the cerebellum: the length of the cell cycle and the duration of the different phases of the cycle, including the DNA synthesis time appears to be normal. However, the external granular layer of the cerebellum contains fewer cells than in control at 12 days. Pyknotic nuclei are prominent in the granule cell layer of the hypothyroid cerebellum at this age. These amount to an estimated loss of about 1% of the total cerebellar cell population in 24 h. It is suggested that death of granule cells is for the most part a consequence of reduced Purkinje cell dendritic arborization, with failure of parallel fibre/Purkinje cell synaptogenesis. In the second postnatal week, granule cell death and reduced numbers of cells in the germinal zone can account to a great extent for the observed shortfall in cerebellar DNA content. The eventual attainment of normal cell numbers in the cerebellum of hypothyroid rats is related to a persistent external granular layer in the forth and fifth postnatal weeks.
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Hodge GK, Butcher LL, Geller E. Hormonal effects on the morphological differentiation of layer VI cortical cells in the rat. Brain Res 1976; 104:137-41. [PMID: 1247899 DOI: 10.1016/0006-8993(76)90653-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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28
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Hormones and Brian Development. PROGRESS IN BRAIN RESEARCH 1976. [DOI: 10.1016/s0079-6123(08)60988-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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29
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Lewis PD, Balázs R, Patel AJ, Johnson AL. The effect of undernutrition in early life on cell generation in the rat brain. Brain Res 1975; 83:235-47. [PMID: 1109296 DOI: 10.1016/0006-8993(75)90933-6] [Citation(s) in RCA: 86] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In undernourished rats aged up to 21 days, the DNA synthesis period in dividing cells of the subependymal and external granular layers is consistently and markedly prolonged, while rates of cell production from these layers are only slightly altered. Cell cycle times are unchanged up to the end of the first week of life and prolonged from day 12. The G1 phase is markedly shortened at 1, 6 and 12 days of age. It would appear that, in comparison with controls, disappearance of the external granular layer is delayed, and cell numbers in both germinal layers may be reduced.
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Clos J, Crépel F, Legrand C, Legrand J, Rabié A, Vigouroux E. Thyroid physiology during the postnatal period in the rat: a study of the development of thyroid function and of the morphogenetic effects of thyroxine with special reference to cerebellar maturation. Gen Comp Endocrinol 1974; 23:178-92. [PMID: 4837801 DOI: 10.1016/0016-6480(74)90127-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Peterson GR, Webster GW, Shuster L. Characteristics of choline acetyltransferase and cholinesterases in two types of cultured cells from embryonic chick brain. Dev Biol 1973; 34:119-34. [PMID: 4787599 DOI: 10.1016/0012-1606(73)90343-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Hajós F, Patel AJ, Balázs R. Effect of thyroid deficiency on the synaptic organization of the rat cerebellar cortex. Brain Res 1973; 50:387-401. [PMID: 4705507 DOI: 10.1016/0006-8993(73)90740-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Bass NH, Young E. Effects of hypothyroidism on the differentiation of neurons and glia in developing rat cerebrum. J Neurol Sci 1973; 18:155-73. [PMID: 4690640 DOI: 10.1016/0022-510x(73)90003-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Balázs R, Patel AJ. Factors affecting the biochemical maturation of the brain. Effect of undernutrition during early life. PROGRESS IN BRAIN RESEARCH 1973; 40:115-28. [PMID: 4153948 DOI: 10.1016/s0079-6123(08)60682-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Nicholson JL, Altman J. The effects of early hypo- and hyperthyroidism on the development of rat cerebellar cortex. I. Cell proliferation and differentiation. Brain Res 1972; 44:13-23. [PMID: 5056973 DOI: 10.1016/0006-8993(72)90362-9] [Citation(s) in RCA: 319] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Wysocki SJ, Segal W. Influence of thyroid hormones on enzyme activities of myelinating rat central-nervous tissues. EUROPEAN JOURNAL OF BIOCHEMISTRY 1972; 28:183-9. [PMID: 4341736 DOI: 10.1111/j.1432-1033.1972.tb01901.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Abstract
The number of synapses in the molecular layer of the rat cerebellum is reduced by early hypo-and hyperthyroidism within 30 days. Hypothyroidism retards synaptogenesis after 10 days, while hyperthyroidism accelerates synaptogenesis initially, but by 21 days the number of synapses is reduced. The sensitivity of developing synapses to thyroid hormone may permit analysis of the events triggering synaptogenesis.
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Balázs R, Brooksbank BW, Patel AJ, Johnson AL, Wilson DA. Incorporation of ( 35 S) sulphate into brain constituents during development and the effects of thyroid hormone on myelination. Brain Res 1971; 30:273-93. [PMID: 5099171 DOI: 10.1016/0006-8993(71)90079-5] [Citation(s) in RCA: 72] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Kiernan JA, Rawcliffe PM. Effects of triiodothyronine on the cerebellar cortex of the new-born rat in tissue culture. EXPERIENTIA 1971; 27:678-9. [PMID: 4104115 DOI: 10.1007/bf02136957] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Balázs R, Kovács S, Cocks WA, Johnson AL, Eayrs JT. Effect of thyroid hormone on the biochemical maturation of rat brain: postnatal cell formation. Brain Res 1971; 25:555-70. [PMID: 5544324 DOI: 10.1016/0006-8993(71)90460-4] [Citation(s) in RCA: 172] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Patel AJ, Balázs R. Effect of thyroid hormone on metabolic compartmentation in the developing rat brain. Biochem J 1971; 121:469-81. [PMID: 5119783 PMCID: PMC1176595 DOI: 10.1042/bj1210469] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
1. The effects of treatment with thyroid hormone (tri-iodothyronine) and of neonatal thyroidectomy on the cerebral metabolism of [U-(14)C]leucine were investigated during the period of functional maturation of the rat brain extending from 9 to 25 days after birth. 2. Age-dependent changes in the labelling of brain constituents under normal conditions appear to depend on changes in the availability of blood-borne [(14)C]leucine resulting from differential rates of growth of body and brain; but developmental changes in the pool size of free leucine and in the rates of protein synthesis and oxidation of leucine are also involved. 3. Treatment with thyroid hormone had no significant effect on the conversion of leucine carbon into proteins and lipids; and the age-dependent changes in the concentration and specific radioactivity of leucine were similar to controls. On the other hand there was an acceleration in the conversion of leucine carbon into amino acids associated with the tricarboxylic acid cycle. These observations indicate that leucine oxidation was the process mainly affected. 4. The specific radioactivity of glutamine relative to that of glutamate was used as an index of metabolic compartmentation in brain tissue. Treatment with thyroid hormone advanced the development of metabolic compartmentation. 5. Neonatal thyroidectomy led to a marked decrease in the conversion of leucine carbon into proteins and lipids and to a significant increase in the amount of (14)C combined in the amino acids associated with the tricarboxylic acid cycle. The age-dependent increase in the glutamate/glutamine specific-radioactivity ratio was strongly retarded. 6. The increased conversion of leucine carbon into cerebral amino acids applied to glutamate and aspartate, but not to glutamine and gamma-aminobutyrate. This observation facilitated the understanding of the effects of thyroid deprivation on brain metabolism and provided new evidence for the allocation of morphological structures to the metabolic compartments in brain tissue. 7. In contrast with the marked effects of the thyroid state on metabolic compartmentation, it had relatively little effect on the developmental changes in the concentration of amino acids in the brain. 8. The rate of conversion of leucine carbon into the ;cycle amino acids' both under normal conditions and in thyroid deficiency indicated a special metabolic relationship between glutamate and aspartate on the one hand, and glutamine and gamma-aminobutyrate on the other.
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Cocks JA, Balázs R, Johnson AL, Eayrs JT. Effect of thyroid hormone on the biochemical maturation of rat brain: conversion of glucose-carbon into amino acids. J Neurochem 1970; 17:1275-85. [PMID: 5457630 DOI: 10.1111/j.1471-4159.1970.tb03376.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Jost A, Picon L. Hormonal control of fetal development and metabolism. ADVANCES IN METABOLIC DISORDERS 1970; 4:123-84. [PMID: 4922838 DOI: 10.1016/b978-0-12-027304-1.50010-7] [Citation(s) in RCA: 89] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Balázs R, Brooksbank BW, Davison AN, Eayrs JT, Wilson DA. The effect of neonatal thyroidectomy on myelination in the rat brain. Brain Res 1969; 15:219-32. [PMID: 5807766 DOI: 10.1016/0006-8993(69)90321-7] [Citation(s) in RCA: 168] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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