Alpha 2-macroglobulin is an astroglia-derived neurite-promoting factor for cultured neurons from rat central nervous system

The neurite promoting factors in the astroglial conditioned medium (As-CM) were characterized by using primary cultures of embryonic rat neocortical neurons. The factors in the As-CM bind to lectins such as wheat germ agglutinin (WGA), suggesting that they contain sugar moieties. When the WGA-bound fractions were applied on a Superose 6 column, the activity was recovered mainly in two fractions, peak I and peak II. The peak II fraction was further purified by Mono Q anion exchange chromatography. A single protein band of 180 kDa was detected in the final Mono Q fraction by sodium dodecylsulfate polyacrylamide gel electrophoresis. The molecular weight coincided with that of alpha 2-macroglobulin (alpha 2M). Western blotting showed that the single protein band was reacted with anti-alpha 2M antibody but not with anti-fibronectin and anti-laminin antisera. The neurite-promoting activity of the Mono Q fraction was inhibited by anti-alpha 2M antibody. Furthermore, commercially available alpha 2M also promotes neurite outgrowth in our assay system. These results strongly suggested that alpha 2M is one of the neurite-promoting factors in the As-CM.

[The new cassette EEG recording system: its application to epileptic children]

We designed a new cassette EEG recording system which consists of a recording block (an ambulatory-type data recorder and a newly developed pre-amplifier) and a reproduction block (a fixed-type data recorder, a personal computer equipped with A/D converting board and an intervening EEG device for a bandpass filter). This system was applied to 36 epileptic children, and 33 ictal records were obtained. The seizure type could be precisely classified by a comparative analysis of the data computed from this system and from the ictal symptoms. Three representative cases were presented with actual analysis procedures.

Tetrahydrobiopterin-dependent production of L-dopa in NRK fibroblasts transfected with tyrosine hydroxylase cDNA: future use for intracerebral grafting

In the present study, tyrosine hydroxylase (TH; EC 1.14.16.2) cDNA was transfected into cultured fibroblasts and the production of L-3,4-dihydroxyphenylalanine (L-DOPA) was determined. Type 2 TH cDNA was transfected into fibroblasts (NRK-49F) derived from the normal rat kidney, and the expression of the TH minigene was screened by immunocytochemical staining and immunoblotting analysis with TH antiserum. Several clones of the NRK transfectants that produce TH molecules were obtained. The expressed TH molecules showed high enzyme activity in a complete assay system in vitro. However, L-DOPA was not detected in the cultured cells due to the possible absence of de novo synthesis of (6R)-L-erythro-tetrahydrobiopterin (BH4) in these cells. When BH4 was added to the medium, a large amount of L-DOPA was detected not only in the cells but also in the medium. These findings may aid in regulating the amount of L-DOPA secretion from cells after they are transplanted into the brain.

Histochemical studies on hyaluronic acid in the developing human retina

Changes in the distribution of hyaluronic acid in the developing human retina were investigated histochemically with alcian blue staining and the Streptomyces hyaluronidase digestion method using 56 human embryos and fetuses ranging from 5 to 41 weeks of gestational age. Hyaluronic acid was first detected in the inner layer of the retina at 12 weeks. The site of accumulation extended towards the outer layer by 20 weeks. At the neonatal stage, longitudinal fibers, possibly the processes of Müller cells, were proved to contain hyaluronic acid. These findings suggest that Müller cells produce hyaluronic acid transiently from 12 weeks' gestation to the neonatal stage.

Xenogeneic neural transplantation: role of vasculature and MHC antigen in immunological rejection

The reconstruction of blood vessels in a graft is one of the important events inducing immunological rejection. First, we investigated the reconstruction of blood vessels in a graft by using a monoclonal antibody against mouse endothelial surface antigen 1. Secondly, the lymphocyte proliferative response to Ia antigen were examined in mixed lymphocyte cultures by using monoclonal antibodies against Ia antigen. The results show that the blood vessels originating in the host tissue inoculate with those originating in the donor graft tissue and that the expression of Ia antigen on the vascular endothelial cells plays an important role in the immunological rejection through sensitization of peripheral lymphocytes.

[An analysis of ictal EEGs by a newly developed ambulatory cassette EEG system]

We evaluated the efficiency of a newly developed cassette EEG recording device and our system for detecting and analyzing ictal EEGs in epileptic children. We got 13 ictal records from 16 epileptic children. We could precisely differentiate and diagnose their classifications of seizures by comparative analyses of ictal records and clinical symptoms. We discussed the characteristics of our system, and described actual analysis methods in 3 cases as examples. It was concluded that our system offered valuable information about ictal events in epileptic children.

[Regulation of neuronal development by astroglia]

Accumulating lines of evidence indicated that glial cells play important roles in regulating the neuronal development. It has been reported by a number of authors that astroglia promote the survival of neurons and the neurite outgrowth by several diffusible factors and membrane-associated factors. In the present article, we have reviewed the astroglia-derived bioactive substances which possibly affect the neuronal development in the central nervous system.

Mosaic reconstruction of blood vessels in mouse neocortical tissue transplanted into the third ventricle of rat brain

Newborn mouse neocortical tissue was transplanted into the third ventricle of rat brain and the reconstruction and the origin of the blood vessels were investigated by using a monoclonal antibody against mouse endothelial surface antigen-1 (MESA-1). It was clearly demonstrated that some of the blood vessels in the graft originated in the donor mouse neocortical tissue. An India ink perfusion experiment revealed that the blood was supplied to the MESA-1-positive blood vessels. Furthermore, electron microscopic immunohistochemical studies demonstrated the existence of a mosaic reconstruction of blood vessels which consisted of mouse- and rat-derived vascular endothelial cells. It was concluded that the blood vessels originating in the donor tissue and those originating in the host tissue inoculate with each other in the grafted tissue.

Synthesis of L-3,4-dihydroxyphenylalanine by tyrosine hydroxylase cDNA-transfected C6 cells: application for intracerebral grafting

In the present study, we obtained genetically manipulated nonneuronal cells which synthesize a catecholamine precursor for future use in intracerebral grafting. Human type 1 tyrosine hydroxylase (TH; EC 1.14.16.2) cDNA was inserted into eukaryotic expression vector pKCRH2 and was co-transfected into C6 cells with plasmid pSV2neo. Expression of the TH minigene was screened by immunohistochemical staining with TH antibody and immunoblotting analysis. Several clones of the C6 transfectants that produce TH molecules were obtained. These cells showed TH activity, and the product, L-3,4-dihydroxyphenylalanine (L-DOPA), was detected intracellularly due to the absence of L-amino acid decarboxylase (EC 4.1.1.28) activity. It was found that a large amount of L-DOPA was released from the cells into the culture medium. These transfectants were transplanted into rat brain, and the expression of TH was examined immunohistochemically. On the 10th day following transplantation, a mass of C6 cells which was heavily stained with TH antibody was observed in the brain. These findings may provide us with an opportunity to investigate the effects of intracerebral transplantation of nonneuronal cells that produce catecholamine or its precursor.

[Current advances in neural transplantation]

In the present study, we obtained genetically manipulated non-neuronal cells which synthesize a catecholamine precursor for future use in the intracerebral grafting. Human type 1 tyrosine hydroxylase (TH, EC 1. 14. 16. 2) cDNA was inserted into eukaryotic expression vector pKCRH2 and was co-transfected into C6 cells with plasmid pSV2neo. Expression of the TH minigene was screened by immunocytochemical staining with TH antibody and immunoblotting analysis. Several clones of the C6 transfectants that produce TH molecules were obtained. These cells showed TH activity and the product, L-DOPA, was detected intracellularly due to the absence of L-amino acid decarboxylase (AADC, EC 4. 1. 1. 28) activity. It was found that a large amount of L-DOPA was released from the cells into the culture medium. These transfectants were transplanted into rat brain and the expression of TH was examined immunohistochemically. At the 10th day following transplantation, a mass of C6 cells which was heavily stained with TH antibody was observed in the brain. These findings may provide us an opportunity to investigate the effects of intracerebral transplantation of non-neuronal cells that produce catecholamine or its precursor.

[Morphological studies on cataract and small lens formation in neonatal rats treated with monosodium-L-glutamate]

Changes in the transparency and size of lenses in rats were investigated following administration of monosodium-L-glutamate (MSG), MSG (5 mg/g b.w.) was injected subcutaneously on the 9th and 10th days after birth. Morphological changes of the lenses were examined ophthalmoscopically and histologically. Ophthalmoscopically, localized opacity was apparent at the posterior pole of the lens corresponding to the attached portion of hyaloid artery at 1 months of age. The incidence of cataract increased with age, reaching more than 75% at 4 months of age. Morgagni's globules were histologically detected in the opacity of the posterior lens cortex. Degenerative changes of the lens epithelium were observed in the mature cataract. However, the capsules of the lens were well preserved. The size and weight of the lens were smaller than those of controls. Although the pathogenesis of the cataract and small lenses are not clear at the moment, these findings indicate that administration of MSG could be an etiologic factor in cataract formation in the developing rat.

[Experimental studies on microphthalmos formation in neonatal rats treated with monosodium-L-glutamate]

Changes in the eyeball size were investigated in rats treated with monosodium glutamate (MSG) during the neonatal period. Correlations among ocular size and degenerative changes of the retina and optic nerve were also studied ophthalmoscopically and histologically. Rats received MSG 5 times, 2 times or once. In rats which received MSG 5 times, the administration was made at 1, 3, 5, 7 and 9 days of birth. In rats, which received MSG 2 times, the administration was made on 2 subsequent days (1 and 2, 3 and 4, 5 and 6, 7 and 8, 9 and 10, 12 and 13 or 15 and 16 postnatal days). In the group of rats, which received MSG once, the administration was made on each from the 1st to the 15th postnatal day. Microphthalmos formation was clearly observed only in rats with 5 times and 2 times (9 and 10 days) injection of MSG. In these rats, narrowing of retinal vessels, paleness and excavation of optic disks were observed ophthalmoscopically. Total liquefaction of the vitreous body were seen in the same groups. Histological examinations also revealed degeneration of the inner layers of the retina. These findings indicated that the administration of MSG at critical stages during postnatal development induces disturbances of eyeball growth. It was also suggested that the growth of the eyeball is closely associated with the postnatal development of the retina.

Expression of Ia antigen on vascular endothelial cells in mouse cerebral tissue grafted into the third ventricle of rat brain

The mechanisms of the immunological rejection after xenogeneic neural transplantation were investigated with special reference to the expression of class II major histocompatibility complex (MHC) antigen (Ia antigen) on the grafted tissue. Tissue from a newborn mouse cerebral cortex was transplanted into the third ventricle of a 4-week-old rat brain. Infiltration of cytotoxic T-cells into the grafted tissue was investigated immunohistochemically by using a monoclonal antibody (OX-8). The infiltration began 8 days after transplantation and continued until about 4 weeks when the tissue was completely rejected. The expression of Ia antigen was also investigated immunohistochemically. The Ia antigen was first detected in the grafted tissue at 6 days after transplantation. The Ia antigen was considered to be expressed on the vascular endothelial cells judging from the staining patterns and the location of India ink which was perfused from the host's left cardiac ventricle. The perfusion experiments with India ink also revealed that blood was supplied to the grafted tissue from 5 days after transplantation. These results suggest that the expression of Ia antigen on the vascular endothelial cells renders the grafted tissues competent to initiate and participate in the immune reaction. The results also raise a possibility that the expression of Ia antigen is triggered by blood supplied from the host brain. In addition, the results indicate that the Ia-positive blood vessels do not originate in the host brain but are intrinsic to the grafted tissue.

Changes in ganglioside composition and morphological features during the development of cultured astrocytes from rat brain

Changes in ganglioside content over a period of days were examined in astrocytes obtained via cell passage from rat cerebral cortex. Thin-layer chromatography revealed that, in the astrocytes, ganglioside GM1 was absent, the predominant ganglioside being GM3. Also, an increased GD3 content in long-term astrocyte cultures was detected. The morphological features of astrocytes were also studied using immunoperoxidase staining. Astroglial features were characterized by high levels of glial fibrillary acidic protein (GFAP) and vimentin, which are the major intermediate-filament proteins present in astrocytes at an early culture stage. In long-term-cultured (greater than 7 months) astrocytes, vimentin and GFAP were increased in process-bearing cells. Ganglioside GD3 recognized by R24 monoclonal antibody was also expressed in these cells. These results suggest that the increase of ganglioside GD3 in long-term-cultured astrocytes may be related to the appearance of multistellate cells showing strong reactivity against GFAP and vimentin during development over a specified period in culture.

[Morphological and immunohistochemical studies on degenerative changes of the retina and the optic nerve in neonatal rats injected with monosodium-L-glutamate]

Degenerative changes in the retina and the optic nerve were investigated morphologically and immunohistochemically following administration of monosodium-L-glutamate (MSG) in rats. MSG (5mg/g b.w.) was injected subcutaneously every other day for 5 times after birth. The retina and the optic disc was observed ophthalmoscopically at 1, 3 and 6 months after birth. At the same stage, morphological and immunohistochemical changes were also investigated under light microscopy. The neuron of the retinal ganglion cell was identified immunohistochemically with antiserum to neurofilament 200 kD (NF). Glial cells were stained with antisera to glial fibrillary acidic protein (GFAP) and S-100 beta protein, and myelin of oligodendrocytes was also stained with antiserum to myelin basic protein (MBP). Histologically the inner layer of the retina was selectively destroyed, and the optic nerve also showed degeneration, changing into a thin strand. The retinal vessels were narrow and coarse, however, they extended to the peripheral region. Although immunohistochemical staining with NF antiserum was scarcely detected both in the retina and in the optic nerve, glial stainings with GFAP and S-100 beta protein antisera were widely observed in the perivascular space of the retina and in the glial column of the optic nerve. These findings indicated that the ganglion cells and their neurons are significantly affected by MSG, but the retinal vessels and glial cells are rarely affected. Ophthalmoscopically, the optic discs of rats treated with MSG were small and deeply excavated. The vitreous vessels persisted in most cases even at 6th months after birth.(ABSTRACT TRUNCATED AT 250 WORDS)

Reorganization of cerebellar cell suspension transplanted into the weaver mutant cerebellum and immunohistochemical detection of synaptic formation

Dissociated cells prepared from the cerebellar primordia of normal 15-day mouse embryos were grafted into the cerebellum of 1-month-old weaver mutant mice which are characterized by degeneration of cerebellar granule cells during the early postnatal period. The growth of the grafted cells was investigated at 1 month after the operation. Implanted cells were highly developed to form a large mass of tissue in the host cerebellar folia. Histological examination revealed that a trilaminar cortical structure was partially developed in certain areas of the grafted tissue. The implanted granule-like cells were labeled with [3H]thymidine which was injected into the host, suggesting that the granule-like cells actively proliferate in the host cerebellum after the transplantation. In this area, strong immunoreactivity with synapsin I was detected indicating that the dissociated granule cells of the cerebellar primordia are able to develop a synaptic organization in the weaver mouse cerebellum.

Immunohistochemical studies on the proliferation of reactive astrocytes and the expression of cytoskeletal proteins following brain injury in rats

The appearance of reactive astrocytes following brain injury was investigated in 4-week-old rats with special reference to their proliferation and chronological changes in the cytoskeletal proteins. Two days after the injury, glial fibrillary acidic protein (GFAP)-positive cells had increased in number around the lesion and spread to the entire ipsilateral cortex by 3 days after the injury. To investigate the distribution of mitotic cells and its chronological change, immunohistochemical staining with monoclonal antibody to bromodeoxyuridine (BrdU) was performed. BrdU-positive cells began to appear around the lesion and spread to the entire ipsilateral cortex by 3 days and their distribution was the same as that of GFAP-positive cells. To investigate the association of GFAP-positive cells with cell division, double labeling experiments using [3H]thymidine autoradiography and immunohistochemical staining with antiserum to GFAP were performed. Cells doubly labeled with GFAP and [3H]thymidine were localized in the area adjacent to the lesion, in the molecular layer of the cortex and in the white matter. By contrast, none of the cells were doubly labeled in the IInd to VIth layers of the cortex. Furthermore, only astrocytes in the former areas expressed vimentin transiently from 2 to 10 days after the injury. In the rats administered vincristine, cells arrested during mitosis were found in the regions which express vimentin. From these results, it was suggested that astrocytes in the molecular layer of the cortex and the white matter adjacent to the lesion proliferated in response to the injury and expressed vimentin transiently, then acquired GFAP, and that astrocytes in the IInd to VIth layers of the cortex became reactive astrocytes without mitosis.

Motor cortical kindling in cats: a comparison of adult cats and kittens

We compared the establishment of motor cortex kindling by daily electrical stimulation in adult cats and in 4-week-old kittens. All the adult cats and kittens examined reached a stable state of kindled seizures. There was no significant difference in afterdischarge (AD) thresholds, the course of clinical seizure development, or the number of stimuli required for the establishment of kindling between adult cats and kittens. During the development of the kindling stage, AD frequency increased in both adult cats and kittens, although AD duration did not show a clear change.

Immunohistochemical studies on synapse formation by embryonic cerebellar tissue transplanted into the cerebellum of the weaver mutant mouse

Normal cerebellar tissue, obtained from 15-day-old CBA/JNCij mouse embryos, was transplanted into the cerebellum of 4-week-old weaver mice. At the 6th week after the transplantation, the grafted tissue was distinguishable from the host cerebellum, developing a trilaminar organization. The formation of synapses by the implanted granule cells was analyzed immunohistochemically with antiserum against synaptic vesicle protein, Synapsin I. Some areas in the host cerebellum as well as in the grafted tissue were intensely stained by anti-Synapsin I serum, suggesting that the implanted granule cells make synaptic contacts with the neuronal cells.

Subcultured astrocytes suppress the proliferation of neuroblasts in vitro

The effects of subcultured astrocytes on the proliferation of neuronal precursor cells (neuroblasts) from rat embryonic cerebral hemispheres were examined. The survivability of neurons and the neurite outgrowth were significantly enhanced by the subcultured astrocytes compared to those of neurons plated on poly-L-lysine-coated coverslips. The incorporation of [3H]thymidine into neuroblasts was remarkably suppressed by the subcultured astrocytes indicating that the astrocytes inhibit the proliferation of neuroblasts. These results suggest that astrocytes enhance the maturation of neuroblasts possibly via either cell-cell contact or trophic substances.

Possible association of platelet-derived growth factor (PDGF) with the appearance of reactive astrocytes following brain injury in situ

The association of platelet-derived growth factor (PDGF) with the appearance of reactive astrocytes following injury was investigated by using a specific antagonist of PDGF, Trapidil. The cerebral cortex of 4-week-old male rats was unilaterally injured with a 22-gauge needle. Immunohistochemical staining with antiserum to glial fibrillary acidic protein revealed that reactive astrocytes had increased in number around the wound by 2 days following the injury and had spread to the ipsilateral areas distant from the wound by 3 days. The appearance of reactive astrocytes in areas distant from the wound was dramatically suppressed by the administration of Trapidil. This finding indicates that PDGF might play a role in gliosis following injury.

The effect of arcuate nucleus transplantation on the development of the anterior pituitary in monosodium glutamate-treated rats

Treatment with monosodium glutamate (MSG) during the neonatal period is known to produce a selective lesion of the arcuate nucleus in rat brain, which is the major site of production of growth hormone releasing-hormone (GRH), followed by a secondary reduction in growth hormone (GH) synthesis in the anterior pituitary. Normal arcuate nuclei from hypothalamic areas of newborn rats were transplanted into the third ventricles of 27-day-old rats which were treated with MSG on alternate days for the first 10 days of life. Ninety days after birth, the anterior pituitaries were examined for GH synthesis by immunohistochemical staining with GH antiserum. The results indicated that the impaired GH synthesis in the anterior pituitary treated with MSG was partially restored in some recipients by grafts of arcuate nuclei in which the GRH-containing neurons were clearly detected by immunohistochemical staining with GRH antiserum.

Production of monoclonal antibody to 2',3'-cyclic nucleotide 3'-phosphodiesterase from bovine cerebral white matter

Lewis rats were immunized with partially purified 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) from bovine cerebral white matter and the spleen cells were fused with cell of a mouse myeloma cell line (SP-2). The production of monoclonal antibody was detected by enzyme-linked immunoadsorbent assay, immunohistochemical staining of bovine cerebrum, Western blotting analysis, and CNPase binding assay. Monoclonal antibody that specifically binds CNPase molecules was obtained. However, the antibody did not suppress the enzyme activity. Western blotting analysis demonstrated that the monoclonal antibody binds both CNa (Wla) and CNb (Wlb). The monoclonal antibody was identified as being of the IgG2c subclass. Immunohistochemical examination revealed that the myelin sheath in the CNS was heavily stained with the monoclonal antibody in several species (bovine, mouse, rat, and human). In contrast, peripheral nervous system myelin was not stained even in bovine tissue. These results suggest that the monoclonal antibody obtained in the present study specifically recognizes the CNPase molecules in the CNS.

Septal deafferentation enhances the neurotrophic effects of rat hippocampus on cultured neural cells from the central nervous system

Neurotrophic effects (NTEs) of various brain regions of 4-week-old rats were examined in primary culture of rat embryonic cerebral hemispheres. Extracts of the hippocampus, brainstem and septal nucleus highly enhanced the survivability of neuronal cells and the division of non-neuronal cells by 9 days. The septohippocampal tract (fimbria fornix) was cut and the effect on the neurotrophic activity in the hippocampus was examined. The NTEs of hippocampal extracts remained unchanged 3 days after septal deafferentation, was significantly increased by 7 days, peaked at 14 days and returned to the basal level by 21 days.

Transplantation of bulk-separated oligodendrocytes into the brains of shiverer mutant mice: immunohistochemical and electron microscopic studies on the myelination

Normal oligodendrocytes were separated from 7-day-old mouse (BALB/c) brains by the Percoll gradient method. Immunohistochemical staining with an anti-galactocerebroside serum revealed that about 85% of the separated cells were oligodendrocytes. The oligodendrocytes were transplanted into the corpus striatum of 4-week-old shiverer mutant mice which are characterized by the lack of myelin basic protein (MBP). Myelination by the implanted oligodendrocytes was investigated immunohistochemically and electron microscopically 6 weeks after the operation. Certain areas in the corpus striatum were intensely stained with antiserum to MBP. Electron microscopic examination showed that some axons were surrounded by normal type myelin sheaths with major dense lines. These results clearly indicate that matured oligodendrocytes are able to survive and myelinate the host axons even in the adult brain.

Effects of glycoprotein synthesis inhibitor on myelination in rat cerebellum

Effects of a glycoprotein synthesis inhibitor on myelination were investigated in rat cerebellum. The glycoprotein synthesis inhibitor, tunicamycin (TM), was injected intracranially into newborn rats. The activity of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) in the cerebellum was significantly reduced in 2-week-old animals and was restored to the normal level by age 3 weeks. When TM was injected into newborn rats every 3-4 days for a total of 6 times, CNPase activity was still low at 3 and 4 weeks. Immunohistochemical stainings for CNPase and myelin-associated glycoprotein (MAG) were performed on paraffin sections of multiple-TM-injected cerebellum at 3 weeks. The intensity of the staining with MAG antiserum in the white matter was clearly decreased in TM-treated cerebellum compared with the control. The myelin in the granule cell layer was poorly stained with CNPase antiserum in TM-treated cerebellum. Subcellular fractionation was carried out and the CNPase activity in each fraction was measured. The CNPase activity in the myelin fraction (P2A) from the TM-treated cerebellum was significantly lower than that in the control. In contrast, the activity in the synaptosomal (P2B) and microsomal (P3) fractions from the multiple-TM-injected cerebellum was higher than in those from the controls. Polyacrylamide gel electrophoretic patterns of the P2A fractions were analyzed. The P2A fraction from TM-treated cerebellum contained less Wolfgram protein than the control. These results suggest that glycoprotein synthesis plays certain roles in myelination in the central nervous system.

Disorders in myelination in the twitcher mutant: immunohistochemical and biochemical studies

The twitcher is an autosomal recessive mutant mouse characterized by absence of galactosylceramidase. The twitcher shows clinical and histological features similar to those of human Krabbe-type leukodystrophy. We here present the results of a neurochemical and immunohistochemical analysis of the twitcher. Electrophoretic analysis revealed that in the particulate fraction of the spinal cord, myelin basic proteins (MBP) and proteolipid protein were decreased, and in the sciatic nerve fibers, PO protein, X, Y and MBP were clearly decreased. 2',3'-Cyclic nucleotide 3'-phosphodiesterase (CNPase) activities of the pallium cerebri, brain stem and spinal cord of the twitcher were about 20% less than those of the control. However, in the sciatic nerve, the activity was half that of the control. Immunohistochemical studies were carried out by means of antisera against MBP and CNPase. There were clear patches indicating both MBP- and CNPase-negative reactions in the white matter of the central nervous system from the twitcher. The reaction on the section of sciatic nerve fibers from the twitcher showed a positive reaction only in a very limited number of fibers with both MBP and CNPase antisera. A clear astrocytic hypertrophy was detected by the antiserum against glial fibrillary acidic protein (GFAP). Even in the grey matter of the cerebral cortex, strong GFAP-positive astrocytes were clearly observed.

Immunohistochemical studies on mouse cerebral cortex grafted into the third ventricle of rats treated with cyclosporin A

Newborn mouse cerebral cortex was transplanted into the third ventricle of an adult rat brain. After the operation, the immunosuppressant cyclosporin A was administered daily for two weeks, and the grafted tissue was examined immunohistochemically at the 4th week. Neurons, astroglias and oligodendroglias were positively stained by antibodies against neurofilament, glial fibrillary acid protein and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), respectively. The CNPase staining indicated that myelination had occurred in the grafted tissue. Thus both neuronal and glial elements in the grafted tissue could survive and mature in the third ventricle of the different species upon administration of cyclosporin A.

Immunohistochemical localization of 2',3'-cyclic nucleotide 3'-phosphodiesterase and myelin basic protein in the central nervous system of the jimpy and the normal mouse

We describe the immunohistochemical localization of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) and myelin basic protein (MBP) in CNS of the jimpy mutant mouse which is characterized by dys- and demyelination. In controls, the CNPase and MBP were localized exclusively in white matter in the CNS. The jimpy mutant mice were severely affected: A very weak reaction was observed in the white matter. Very few CNPase- and MBP-positive myelin sheaths were observed, and some degradation products were also observed after reaction with antisera against both CNPase and MBP. The immunohistochemical reaction in the jimpy mice showed a similar localization in both CNPase and MBP.

Cyclosporin A enhances the survivability of mouse cerebral cortex grafted into the third ventricle of rat brain

The effect of the immunosuppressant cyclosporin A on the survivability of newborn mouse cerebral cortex transplanted into the third ventricle of adult rats was investigated. Hematoxylin staining revealed that the transplanted mouse brain tissue was rejected by 4 weeks after the transplantation in the control group. In contrast, a large mass of grafted tissue was clearly detected in the third ventricle even 4 weeks after the transplantation in the cyclosporin A-treated group, and the grafted tissue was heavily stained with Thy-1.2 mouse monoclonal antibody. The results indicate that cyclosporin A is an effective immunosuppressant in neuronal transplantation as well as in transplantation of other organs.

Impaired development of rat cerebellum induced by neonatal injection of the glycoprotein synthesis inhibitor, tunicamycin

The effects of the protein glycosylation inhibitor tunicamycin on the postnatal development of the rat cerebellum were examined in vivo. Tunicamycin (0.2 micrograms) was injected intracranially into 1-day-old rats. Inhibition of glycosylation of the macromolecules in the cerebellum by tunicamycin treatment was suggested by a reduced incorporation of [3H]glucosamine into the trichloroacetic acid (TCA)-insoluble fraction. The tunicamycin treatment did not affect gain in body weight significantly. However the cerebellar weight was significantly reduced by 30-40% compared with that of the controls. Development of GABAergic and cholinergic innervations in the hypoplastic cerebellum was examined by measuring the activities of glutamate decarboxylase (GAD) and choline acetyltransferase (ChAT). The specific activity and the total activity of GAD were significantly reduced in the tunicamycin-treated cerebellum. In contrast the specific activity of ChAT was significantly increased, whereas the total activity of ChAT per cerebellum was identical with that of the controls. These results suggest that the intracranial injection of tunicamycin affects the postnatal development of rat cerebellum, such as GABAergic and cholinergic innervations.

Clonazepam monotherapy for epilepsy in childhood

Sixty patients (age-range one month to 14 years) with other types of epilepsy than infantile spasms were treated with clonazepam. Disappearance of seizures and normalization of abnormal EEG with disappearance of seizures were recognized in 77% and 50%, respectively. Seizures disappeared in 71% of the patients with generalized seizures and 89% of partial seizures. Improvement of abnormal EEG was noticed in 76% of diffuse paroxysms and in 67% of focal paroxysms. In excellent cases, mean effective dosages were 0.086 +/- 0.021 mg/kg/day in infants and 0.057 +/- 0.022 mg/kg/day in schoolchildren, this difference was statistically significant (p less than 0.005). The incidence of side effects such as drowsiness and ataxia was only 5%.

Immunohistochemical study on oxytocin-like substance in the human placenta

Our previous studies have demonstrated that a large quantity of oxytocin (OT)-like substance exists in human placental tissue. In the present study, the localization of the OT-like substance in the human placenta was investigated by the PAP (peroxidase and antiperoxidase complex) immunohistochemical method. The results demonstrated that the site of syncytiotrophoblast was positively stained by specific antiserum to OT, whereas the tissue was not significantly stained by normal rabbit serum (NRS). These results suggest that the OT-like substance might be localized in syncytiotrophoblast of the placental tissue.

Familial clustering of situs inversus totalis, and asplenia and polysplenia syndromes

We report on a family in which a male infant had the asplenia syndrome, a younger brother had the polysplenia syndrome, and their father had situs inversus totalis. The occurrence of the asplenia and the polysplenia syndromes in a sibship of the present family and in two other previously reported sibships indicates that the two syndromes are causally and pathogenetically related to each other. If it is assumed that the father had an incomplete form of the polysplenia complex, then the condition in this family either is an autosomal dominant trait or is multifactorially determined.

Immunohistochemical localization of 2',3'-cyclic nucleotide 3'-phosphodiesterase and myelin basic protein in the chick retina

Antisera against bovine 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) and against chick myelin basic protein (MBP) were raised in New Zealand white rabbits. The specificity of CNPase antiserum was examined by Ouchterlony double-immunodiffusion test and immunoadsorption assay. With use of the specific antiserum, immunohistochemical localizations of CNPase and MBP were investigated in the chick retina. Light microscopic immunohistochemical studies have shown that MBP is localized in the optic nerve fiber layer and that CNPase is localized in the optic nerve fiber and photoreceptor layers. Electron microscopic immunohistochemical examinations demonstrated that the myelin-like neural sheaths in the optic nerve fiber layer were clearly stained by both antisera, whereas the membranes of the Müller cell were not stained. In the photoreceptor layer, membranes of the inner and outer segments of rod and cone photoreceptor cells were intensely stained by CNPase antiserum. However, these portions were not stained by MBP antiserum. Membranes of bipolar cells, amacrine cells, horizontal cells, and ganglion cells were not stained by either antiserum.

Dissociation of enhanced ornithine decarboxylase activity and optic nerve regeneration in goldfish

The significance of a previously observed increase in retinal ornithine decarboxylase (ODC, EC 4.1.1.17) following optic nerve crush was investigated in goldfish using a specific irreversible inhibitor of ODC, alpha-difluoromethylornithine (DFMO). Retinal ODC activity and putrescine levels were reduced 80% and 40%, respectively, by intraperitoneal injection(s) of DFMO. In fish in which the right optic nerve was crushed and DFMO was injected at the time of crush, at 2 days and at 4 days later, retinal ODC levels were maximally decreased after the third injection and returned to normal levels by 14 days post-crush (PC). Retinal tubulin synthesis was examined at 10 days PC. No difference in the post-crush/normal ratio of tubulin synthesis was observed between saline-injected and DFMO-injected groups. Neuritic extension was also examined in retinal explant cultures from 11-day PC retina. The neuritic growth index of DFMO-treated retinas did not differ from that of control retinas. Behavioral studies revealed no difference in the rate of recovery of vision between the two groups. Similar results were obtained in experiments using fish maintained in a 0.1% DFMO solution. These results suggest that the increase in retinal ODC associated with nerve crush does not play a causal role in restoration of function.

Effects of bovine growth hormone on the retarded cerebral development induced by neonatal hydrocortisone intoxication

In comparison with normal controls, hydrocortisone-intoxicated rats (HC rats) had smaller cerebra, lowered 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) activity, and greatly reduced learning ability. The reduction in cerebral weight and DNA content was considered to be caused by a decrease in the number of proliferating glial cells, because the usual postnatal elevation of thymidine kinase (TK) activity was found to be suppressed in the cerebra from the HC rats. Electron microscopic observation of the pituitary gland revealed that the 5-day-old HC rat contained growth hormone (GH) secretory cells which were fully packed with GH granules, suggesting a disorder in the system which releases GH. In an attempt to promote cerebral development in the HC rats, we administered bovine GH (bGH) to some of the HC rats daily from the day of birth until weaning (HC + bGH rats). In the HC + bGH rats, the cerebral DNA was restored to normal levels and a concomitant increase in TK and CNPase activity was noted. Furthermore, in the brightness discrimination test, whereas the HC + bGH rats attained the learning ability of the normal controls after only 10 sessions, the HC rats were unable to reach an equivalent level even after 25 sessions.

2-Deoxyglucose incorporation in the cerebellum of weaver and nervous mutant mice

The 2-deoxyglucose autoradiographic method has been used to study activity in cerebellum of the weaver and nervous mutant mice. Patterns of 2-deoxyglucose incorporation into the cerebral hemispheres from weaver and nervous strains did not differ significantly from those of the controls. In the normal cerebellum, 2-deoxyglucose incorporation was maximal in the granular layer, where mossy fibers form synapses with the dendrites of granule cells. In the cerebellum of nervous mice, which lacks Purkinje cells, the incorporation of the 2-deoxyglucose was maximal in the granular layer, but the incorporation into the molecular layer appeared less than in the control. The incorporation into the cerebellum from weaver, which lacks granule cells, was much higher than that of the control, the maximal incorporation being found in the Purkinje cell layer and in cell masses located in the white matter. These data suggest that the heterologous synapses that mossy fibers or climbing fibers form with the cells in the Purkinje cell layer and the cells in the white matter in the weaver cerebellum are functional.

Increased activity of ornithine decarboxylase in goldfish following optic nerve crush

Ornithine decarboxylase (ODC) activity increased in goldfish retina, brain, and kidney several days following unilateral intraorbital optic nerve crush. Activity in both retinas followed a similar time course, an elevation being first detectable 3 days following crush, maximal on day 5 and returning to control levels by day 7. Increases were significantly higher in the retina on the lesioned side than in control retina. If one eye was surgically removed, a more prolonged elevation of ODC activity was seen in the remaining eye than was observed in control retinas following contralateral nerve crush. Sham operation or behavioral stress secondary to aversive electrical shock did not lead to significant increases in ODC activity in brain or retina. Explants of retinas whose optic nerve had been crushed 10--14 days prior to explantation, as well as those derived from the unlesioned side, showed increases in ODC activity following addition of beta-NGF to the medium. The response was greater in post-crush retinas than in control retinas. These results taken together suggest an increased responsiveness of the regenerating retina to stimuli that lead to increased ODC activity. While the nature of the in vivo signal(s) may be complex, it is inferred that degenerative changes in the distal stump play a significant role.

Ornithine decarboxylase activity in retinal explants of goldfish undergoing optic nerve regeneration

Retinal explants cultured in the presence of fetal calf serum (FCS) exhibit an increase in the activity of ornithine decarboxylase which is maximal several hours after explantation. The measured activity of this enzyme is higher in explants of retinas whose optic nerve had been crushed several days previously (post-crush, PC) than in control (normal, N) retinas. The addition of rabbit antibodies against nerve growth factor (NGF) to the incubation medium does not block this stimulatory effect of FCS, a result suggesting that factors other than NGF present in FCS are responsible for the observed stimulation. An inhibitor of ODC synthesis, diaminopropane (DAP), and an irreversible inhibitor of ODC activity, alpha-DL-difluoromethylornithine (alpha-DFMO), each suppressed the FCS-stimulated ODC activity when added to the culture medium. Since FCS addition also promotes neuritic outgrowth from PC goldfish retinal explants, we explored the possible relationship of the stimulated ODC activity and the ability of explants to extend neurites. Concentrations of DAP or alpha-DFMO that block ODC activity also suppress neuritic outgrowth. Possible non-specific actions of the drugs unrelated to the block of ODC are examined. While the increases in OCD activity seen in PC and N goldfish retinas explanted into FCS-containing medium may be a requisite, they cannot be sufficient to support neuritic outgrowth. Intrinsic changes in the retinal explant secondary to crush of its optic nerve as well as factor(s) present in FCS that may be unrelated to the stimulation of ODC activity also appear necessary for neuritic outgrowth.

Uridine metabolism in the goldfish retina during optic nerve regeneration: cell-free preparations

The activities of uridine kinase (EC 2.7.1.48), uridine monophosphate (UMP) kinase (EC 2.7.1.3.14), and uridine diphosphate (UDP) kinase (EC 2.7.4.6) were measured in retinal high-speed supernatant fractions following unilateral optic nerve crush in the goldfish. The enzyme activities followed a similar time course, with initial increases 2-3 days following nerve crush, peak activity at 4 days, and a gradual return to basal levels by day 21. The magnitude of the stimulation on day 4 was about 35% in each case. Activities of two enzymes of intermediary metabolism, pyruvate kinase (EC 2.7.1.40) and lactic dehydrogenase (EC 1.1.1.27), were not altered, indicating that the coordinate increases in nucleoside and nucleotide kinase activities were specific responses to the nerve injury. The increased labeling could not be explained by altered phosphohydrolytic activities. The nature of the enhancement was further studied in UDP kinase, the most active of the kinases examined. Neither low-molecular-weight components nor substrate availability could account for the observed increase in UDP kinase in the 4 day post-crush retinas. The Km for UDP was unaltered, and a mixing experiment did not support the possibility that stimulatory or inhibitory factors played a role. The enhancement of UDP kinase activity was blocked by injection of actinomycin D following nerve crush. The results suggest that the observed increases in enzymes of uridine metabolism result from their increased formation following nerve crush.

Uridine metabolism in the goldfish retina during optic nerve regeneration: whole retina studies

Accumulation of radioactivity from [3H]uridine in incubations of whole goldfish retinas is increased in the ipsilateral retina during a period of regeneration that follows unilateral optic nerve crush. Brief incubations to investigate the nature of enhanced labeling of the acid-soluble fraction showed a peak uptake 4 days following crush, with a gradual decrease to control levels by 21 days following crush. That nucleoside uptake may not mediate the effect is supported by the observation that the rate of uptake of 5'-deoxyadenosine, a nonmetabolizable nucleoside analog, is the same in post-crush (PC) and normal (N) retinal incubations. Following brief incubations of PC and N retinas with [3H]uridine, there is enhanced labeling in PC retinas relative to N retinas of recovered UMP, UDP, UTP, and uridine nucleotide sugars, whereas recovery of labeled uridine itself is slightly decreased. The results suggest that the increased accumulation of radioactivity in PC retinas following incubation with uridine reflects an increase in the activities of retinal uridine kinase and uridine nucleotide kinases.