bluuebunny/crossref_metadata_2025 huggingface dataset:
Myelin basic protein mRNA localization and polypeptide targeting
Authors: Boccaccio G. L. , Colman D. R.
Published: January 2005

Myelin basic proteins (MBPs), the major peripheral membrane proteins of central nervous system (CNS) myelin, are encoded by mRNAs that are selectively segregated to the myelinating processes of oligodendrocy tes. In order to test whether the intracellular mechanisms responsible for MBP mRNA translocation are oligodendrocyte‐specific, or alternatively, are present in other cell types and may therefore be more general, we have studied the localization of the 14 kD MBP mRNA and its encoded polypeptide (MBP14) in transiently transfected HeLa cells (a cervical carcinoma cell line) and in the rat pheochromocytoma cell line PC12. Unlike the situation in oligodendrocytes in situ, where MBP mRNAs are translocated and become “centrifugally” distributed, in both of the non‐glial cells MBP mRNA was primarily detected in the perinuclear region. The MBP14 polypeptide was found associated with intracellular membranes, and not exclusively with the plasma membrane. Our results indicate that the inability of HeLa and PC12 cells to correctly target MBP mRNAs to the cell periphery leads to a failure to incorporate MBP polypeptides directly into the plasma membrane. Further, the data lend credence to the concept that MBP mRNA segregation appears to be a specific feature of myelin‐forming cells which is required for the precise delivery of the encoded polypeptides to the forming myelin membrane. © 1995 Wiley‐Liss, Inc.
An antineuronal monoclonal antibody that reverses neurite growth inhibition by central nervous system myelin
Authors: Lozano A. M. , Labes M. , Roder J. , Roach A.
Published: January 2005

A component of adult mammalian central nervous system (CNS) myelin causes collapse of neuronal growth cones and inhibits axonal growth, properties that may be responsible for the lack of regrowth of injured axons in the CNS. The molecules and detailed mechanism through which the inhibitory activity acts are not known. To study the cellular molecules mediating the response to this inhibitor, we have used an in vitro neurite growth inhibition assay to screen a panel of monoclonal antibodies raised against rat neuronal membrane proteins, for clones capable of blocking the response. One monoclonal antibody (10D) neutralized the inhibition of neurite growth seen when primary sympathetic neurons, PC12 cells or NG108‐15 cells were grown on inhibitory CNS myelin substrates, but did not promote growth on noninhibitory substrates. 10D reacted with neuronal cells but not myelin substrate proteins. The antigen recognized by 10D appears to play a role in the interaction between neurons and their growth substrates, and is a novel candidate for a cellular receptor or associated signalling molecule mediating the response to myelin inhibitors. © 1995 Wiley‐Liss, Inc.
Increased production of gelatinase B (matrix metalloproteinase‐9) and interleukin‐6 by activated rat microglia in culture
Authors: Gottschall P. E. , Yu X. , Bing B.
Published: January 2005

Activated macrophages produce several matrix metalloproteinases (MMPs), a family of extracellular matrix (ECM)‐degrading enzymes, during wound healing and in other inflammatory states. In response to brain injury, brain microglia become “activated,” in a way similar to peripheral tissue macrophages, a process which includes differentiation and probably invasion and proliferation. Little is known about the ECM‐degrading MMPs that are secreted by microglia upon activation. Thus, it was of interest to determine whether activated microglia secrete MMPs. Conditioned media samples obtained from cultured microglia that were stimulated with various activating agents were subjected to gelatin‐substrate zymography. Microglia constitutively express low levels of a 94‐kDa gelatinase (GLase) activity. Treatment with LPS, zymosan, and fixed Staphylococcus aureus for 24 hr stimulated the activity of the 94‐kDa GLase, 4‐20‐fold, in a dose‐dependent manner. Addition of INFγ inhibited the LPS‐stimulated activity of MMP‐9. LPS, zymosan, and fixed Staphylococcus aureus also stimulated the secretion of IL‐6 from microglia in a dose‐dependent manner. The 94‐kDa GLase activity was Ca++ dependent, it was inhibited by 1,10‐phenanthroline, and it was activated by organomercurial compounds. When immunoblots were performed using specific antisera against the 94‐kDa gelatinase B (MMP‐9) with untreated and LPS‐stimulated conditioned medium samples, a 94‐kDa immunopositive band was observed. Thus, it appears that the 94‐kDa GLase is gelatinase B (MMP‐9). These results indicate that activators of peripheral macrophages are potent secretagogues for the MMPs in cultured microglia. The ability of activated microglia to secrete MMPs suggests that these enzymes may play an important function in the brain parenchyma during inflammatory states. © 1995 Wiley‐Liss, Inc.
Brain injury and tumor necrosis factors induce calbindin D‐28K in astrocytes: Evidence for a cytoprotective response
Authors: Mattson M. P. , Cheng B. , Baldwin S. A. , Smith‐Swintosky V. L. , Keller J. , Geddes J. W. , Scheff S. W. , Christakos S.
Published: January 2005

Calbindin is a 28 kDa calcium‐binding protein expressed in restricted neuronal populations in the mammalian brain where it may play a role in protecting neurons against excitotoxic insults. Recent findings indicate that electrical activity and some neurotrophic factors can induce the expression of calbindin in neurons. We now report that brain injury, effected by systemic administration of the excitotoxin kainate or mechanical trauma, induces expression of calbindin in cells of the corpus callosum and subcortical white matter. Immunohistochemical analysis using antibodies to the astrocyte‐specific proteins (glial fibrillary acidic protein and S‐100β) established the identity of calbindin immunoreactive cells as astrocytes. Because brain injury is known to induce the expression of several neurotrophic factors and cytokines, we employed cultures of hippocampal and neocortical astrocytes to test the hypothesis that such factors can induce expression of calbindin in astrocytes. Tumor necrosis factors (TNFβ and TNFβ), cytokines that are expressed in response to brain injury, induced the expression of calbindin in cultured rat hippocampal and neocortical astrocytes. Two neurotrophic factors, basic fibroblast growth factor and nerve growth factor, did not induce calbindin in astrocytes. TNF‐treated, calbindin‐expressing astrocytes were resistant to acidosis and calcium ionophore toxicity, suggesting that TNFs and calbindin may serve a cytoprotective role in astrocytes in the injured brain. © 1995 Wiley‐Liss, Inc.
Ion channels in rat microglia and their different sensitivity to lipopolysaccharide and interferon‐γ
Authors: Visentin S. , Agresti C. , Patrizio M. , Levi G.
Published: January 2005

In order to study the voltage‐dependent ion channels in microglia, and their possible modulation by proinflammatory substances like lipopolysaccharide (LPS) and interferon‐γ (IFN‐γ) we employed the patch‐clamp technique on purified rat microglial cell subcultures grown for 1–5 days in control condition or after a 24 hour treatment with those agents. Regardless of the culture condition, almost 100% of the cells presented inward‐rectifying (IR) K+ currents identified by the following features: (a) extracellular K+ ‐dependence of Vrev and whole‐cell conductance; (b) inward‐rectifying property; (c) channel blocking mechanism by Cs+; and (d) single channel conductance of 27 pS.

A ‘n’ type outward‐rectifying (OR) K+ current was present in 30% of the cells during the first 2 days of subcultivation. Its occurrence was strongly dependent on the preparation, varying from 0% to almost 80%, and it decreased to 13% of the cells after three days in culture. It showed the following features: (i) threshold of activation close to ‐30 mV; (ii) sigmoid current onset; (iii) voltage‐% kinetics; and (iv) sensitivity to 4‐aminopyridine (4‐AP) and tetraethylammonium (TEA). Furthermore, we detected two ion currents not previously described in microglia: (i) a slowly activating outward current which appeared at potentials more positive than +20 mV and with a reversal potential close to 0 mV, tentatively identified as a proton current; and (ii) a Cl− conductance identified in ion substitution experiments as the current sensitive to the Cl− channel blocker SITS.

The two agents, LPS (20–2,000 ng/ml) and IFN‐γ (10–100 u/ml), shared the following effects: (a) enhancement of membrane capacitance, and (b) increase of OR current amplitude and frequency of occurrence. Moreover, IFN‐γ was also able to increase IR current density, especially in cells with ameboid morphology, while LPS was ineffective. We conclude that the voltage‐dependent ion channel pattern of microglia is more complex than previously thought and that activating agents such as LPS and IFN‐y share some electrophysiological effects, but differ in others. © 1995 Wiley‐Liss, Inc.
Developmental changes of epidermal growth factor‐like immunoreactivity in the human fetal brain
Authors: Kato M. , Mizuguchi M. , Takashima S.
Published: January 2005

We investigated the immunohistochemical localization of epidermal growth factor (EGF) in the developing human brain from 6 weeks of gestation to 3 months postpartum. EGF‐like immunoreactivity varied in its localization and intensity according to the stage of development. At 10‐20 weeks of gestation, EGF‐like immunoreactivity appeared in proliferating and migrating cells in the cerebrum, disappeared thereafter, and appeared again in cortical neurons after 27 weeks of gestation. Astrocytes also showed EGF‐like immunoreactivity from 27 weeks of gestation. These results suggest developmental regulation of EGF expression in the human brain, suggesting Its physiological role in both neuronal and glial cells. © 1995 Wiley‐Liss, Inc.
Chronic opioid treatment of neuroblastoma X dorsal root ganglion neuron hybrid F11 cells results in elevated GM1 ganglioside and cyclic adenosine monophosphate levels and onset of naloxone‐evoked decreases in membrane K+ currents
Authors: Wu G. , Fan S. F. , Lu Z.‐H. , Ledeen R. W. , Crain S. M.
Published: January 2005

Prolongation of the action potential duration of dorsal root ganglion (DRG) neurons by low (nM) concentrations of opioids occurs through activation of excitatory opioid receptors that are positively coupled via Gs regulatory protein to adenylate cyclase. Previous results suggested GM1 ganglioside to have an essential role in regulating this excitatory response, but not the inhibitory (APD‐shortening) response to higher (μM) opioid concentrations. Furthermore, it was proposed that synthesis of GM1 is upregulated by prolonged activation of excitatory opioid receptor functions. To explore this possibility we have utilized cultures of hybrid F11 cells to carry out closely correlated electrophysiological and biochemical analyses of the effects of chronic opioid treatment on a homogeneous population of clonal cells which express many functions characteristic of DRG neurons. We show that chronic opioid exposure of F11 cells does, in fact, result in elevated levels of GM1 as well as cyclic adenosine monophosphate (AMP), concomitant with the onset of opioid excitatory supersensitivity as manifested by naloxone‐evoked decreases in voltage‐dependent membrane K+ currents. Such elevation of GM1 would be expected to enhance the efficacy of excitatory opioid receptor activation of the Gs/adenylate cyclase/cyclic AMP system, thereby providing a positive feedback mechanism that may account for the remarkable supersensitivity of chronic opioid‐treated neurons to the excitatory effects of opioid agonists as well as antagonists. These in vitro findings may provide novel insights into the mechanisms underlying naloxone‐precipitated withdrawal syndromes and opioid‐induced hyperalgesia after chronic opiatf addiction in vivo. © 1995 Wiley‐Liss, Inc.
Zebrafish neurons express two L1‐related molecules during early axonogenesis
Authors: Tongiorgi E. , Bernhardt R. R. , Schachner M.
Published: January 2005

Partial clones coding for two L1‐related genes, zebrafish L1.1 and L1.2, were isolated from a zebrafish embryonic cDNA library. The homology analysis, based on the deduced amino acid sequences of L1.1 and L1.2, revealed that the two molecules are most closely related to each other and to mouse L1. Analysis by in situ hybridization revealed that during embryonic development of the nervous system the L1.1 and L1.2 messages are restricted to postmitotic neurons and that the onset of expression correlates with the initiation of axonogenesis. L1.1 is expressed by all known classes of neurons, consistent with an important general function during axonal outgrowth. Most of the neurons also express L1.2. However, L1.2 either is undetectable or is expressed at very low levels in the neurons of the olfactory placodes, anterior lateral line/acoustic ganglia complex, posterior lateral line ganglion, and in late developing hindbrain neurons. In the spinal cord, L1.2 message is detected only in a subpopulation of Rohon‐Beard cells. This suggests the possibility that different levels of L1.2 expression may serve to distinguish different populations of neurons and their axons. © 1995 Wiley‐Liss, Inc.
Regulation of the rat S100β gene expression: The role of the 2 kb 5′‐upstream sequence in glial specific expression
Authors: Hagiwara N. , Sueoka N.
Published: January 2005

We have studied the role of the 2047 by 5′‐upstream region and 232 by first exon sequence of the rat S100β gene in glial specific expression. S100β luciferase expression vectors carrying serial deletions of the S100β 5′; upstream sequence were constructed and transiently transfected into the peripheral nervous system (PNS) glial‐type cell line RT4‐D6, the PNS neuronal‐type cell line RT4‐E5, and the central nervous system (CNS) glial‐type cell line C6. The hepatoma cell line HTC was also transfected as a non‐neural control. From this functional analysis, we found a glial‐specific positive regulatory sequence(s) mapped between −583 and −106 relative to the transcriptional start site. This region confers a significantly higher level of luciferase expression in the glial‐type cell lines RT4‐D6 and C6 than in the neuronal cell line RT4‐E5 and the hepatoma cell line HTC. Also, a non‐cell type specific positive regulatory element was identified in the first exon sequence between + 78 and + 232. Though non‐cell type‐specific, it was found to have a predominant effect in glial cells. From these observations, we have concluded that the 2047 by 5′;‐upstream region and 232 by of the first exon sequence confers the high levels of S100β expression in glial cells through these two positive elements. © 1995 Wiley‐Liss, Inc.
Developmental changes of nitric oxide synthase in the rat superior colliculus
Authors: Tenório F. , Giraldi‐Guimarães A. , Mendez‐Otero R.
Published: January 2005

We used the activity of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH‐d) to detect the presence of nitric oxide synthase (NOS) in the developing rat superior colliculus. Our results showed that NOS is present in cells and nenropil in the developing and adult rat superior colliculus. The first NOS‐positive cells were detected at postnatal day 7 and were weakly stained. During the following days the number of stained cells increased markedly, reaching a peak by postnatal day 15, coinciding with the time of eye opening in the rat. By the end of the third postnatal week, both the number and intensity of stained cells showed an adult‐like pattern. We conclude that NOS expression lags behind the initial period of reorganization of the retinotectal projection. However, NOS activity could be involved in the subsequent synaptic remodeling and plasticity of the retinocollicular projection. © 1995 Wiley‐Liss, Inc.
Brain‐derived neurotrophic factor induces functional expression and phenotypic differentiation of cultured fetal neuropeptide Y‐producing neurons
Authors: Barnea A. , Cho G. , Lu G. , Mathis M.
Published: January 2005

A series of studies from our laboratory has established an aggregate culture system of fetal rat brain cells that can serve as a model for studying regulatory processes of the developing neuropeptide Y (NPY)‐producing neurons. Using aggregate cultures derived from 17‐day‐old fetal rat cortex, we addressed these questions: (1) Does brain‐derived neurotrophic factor (BDNF) stimulate NPY production, and if so, is stimulation a function of the developmental state of the cultured NPY neuron? (2) Does BDNF induce phenotypic differentiation of NPY neurons? BDNF led to an increase in NPY production and the accumulation of NPY‐mRNA in a dose dependent manner. BDNF did not alter the stability of NPY‐mRNA, judged by the disappearance rate of NPY‐mRNA after blockade of RNA synthesis (estimated t½ was 6‐8 hr). BDNF stimulation of NPY production was dependent on length of exposure to BDNF and on culture‐age. A continuous 8‐day exposure to BDNF resulted in a significantly higher level of NPY production than a pulse of 2 days (comparing BDNF exposure on days 0‐8 vs. 6‐8, or days 8‐17 vs. 15‐17). Moreover, older neurons (age 17 days) produced twice as much NPY as younger (age 8 days) neurons in response to a 2‐day pulse of BDNF (50 ng/ml). BDNF was significantly more effective than NT‐3 in inducing NPY production, and NGF was ineffective. Immunocytochemical analysis of 8‐day NPY neurons revealed that a 2‐day pulse of BDNF induced the appearance of an abundance of morphologically well‐defined neurons bearing an elaborate network of neurites. This was in contrast to the control‐treated NPY neurons, which were morphologically undefined.

In summary, the age‐dependent effect of BDNF on NPY production is consistent with induction of functional expression, rather than promotion of survival, of cultured NPY neurons. The neurotrophin specificity for stimulation of NPY production, and the lack of effect of BDNF on the stability of NPY‐mRNA, implicate the TrkB receptor in mediating transcriptional activation of the NPY gene. Thus, BDNF exerts a dual effect on developing cultured NPY neurons: induction of functional expression, and phenotypic differentiation of immature neurons into mature neurite‐bearing neurons. © 1995 Wiley‐Liss, Inc.
Hyperphosphorylation of TAU and filopodial retraction following microinjection of protein kinase C catalytic subunits
Authors: Cressman C. M. , Shea T. B.
Published: January 2005

Limited proteolysis of protein kinase C (PKC) by calcium‐activated proteolysis cleaves the regulatory and catalytic subunits of PKC, generating a free, constitutively activated kinase (“PKM”) that, unlike the intact parent enzyme, is not calcium‐dependent, and is not restricted to the plasma membrane. These latter properties leave open the possibility that PKM may have access to, and may therefore phosphorylate, substrates normally unavailable to intact PKC. We examined the potential involvement of such aberrant phosphorylation in certain aspects of the neurodegeneration accompanying Alzheimer's disease by microinjecting PKC and PKM, along with a rhodamine‐conjugated dextran tracer, into undifferentiated NB2a/d1 mouse neuroblastoma cells. After 4 hr, cultures were fixed and processed for immunofluorescence with monoclonal antibodies (PHF‐1, ALZ‐50, Tau‐1, AT8) directed against tau in various phosphorylation states followed by fluorescein‐conjugated secondary antibodies. Microinjected cells were localized via co‐injected rhodamine‐conjugated dextran tracer under rhodamine illumination, after which antibody immunoreactivity was examined under fluorescein illumination. Microdensitometric analyses indicated that microinjection of PKC did not increase basal immunofluorescent intensities of the antibodies; by contrast, microinjection of PKM induced threeand twofold increases in PHF‐1 and ALZ‐50 levels, respectively. By contrast, no significant alteration was observed in AT8 and Tau‐1 immunofluorescence following either PKC or PKM microinjection. Whereas undifferentiated NB2a/d1 cells typically elaborate short, filopodia‐like neurites, phase‐contrast microscopy revealed the absence of fllopodia or neurites on PKM‐injected cells, while a similar percentage of PKC‐injected cells elaborated filopodialike neurites as did uninjected cells. Cell‐free analyses confirmed the ability of PKC, in the presence of necessary co‐factors, and PKM to increase PHF‐1 and ALZ‐50 immunoreactivity; no change was observed in AT8 or Tau‐1 immunoreactivity. These findings underscore the possibility that an abnormal amplification in limited PKC proteolysis to generate PKM could, under certain pathological conditions, contribute to neuronal degeneration. © 1995 Wiley‐Liss, Inc.
Acute treatment with pulsed electromagnetic fields and its effect on fast axonal transport in normal and regenerating nerve
Authors: Sisken B. F. , Jacob J. M. , Walker J. L.
Published: January 2005

The mechanism whereby low‐frequency electromagnetic fields accelerate axonal regrowth and regeneration of peripheral nerve after crush lesion is not known. One candidate is an alteration in axonal transport. In this study we exposed unoperated rats for 15 min/day, and rats that had undergone a crush lesion of the sciatic nerve, for 1 hr/day for 2 days, to 2‐Hz pulsed electromagnetic fields. To label fast transported proteins, [3H]‐proline was microinjected into the spinal cord, and the sciatic nerves were removed 2, 3.5, and 5 hr later. The rates of fast axonal transport were obtained for animals in all groups by counting sequential 2‐mm segments of nerves. The following transport rates were found: in unoperated normal sciatic nerve not exposed to PEMF, 373 ± 14 mm/day; in unoperated normal nerve exposed to PEMF, 383 ± 14 mm/day; in sham crush nerves not exposed to PEMF, 379 ± 19 mm/day; in sham crush nerve exposed to PEMF, 385 ± 17 mm/day; in crushed nerves not exposed to PEMF, 393 ± 16 mm/ day; and in crushed nerves exposed to PEMF, 392 ± 15 mm/day. The results of these experiments indicate that (1) a crush injury to the sciatic nerve does not alter the rate of fast axonal transport, and (2) low‐frequency pulsed electromagnetic fields do not alter fast axonal transport rates in operated (crush) or unoperated sciatic nerves. © 1995 Wiley‐Liss, Inc.
Neuritogenic effect of estradiol on rat ventromedial hypothalamic neurons co‐cultured with homotopic or heterotopic glia
Authors: Cambiasso M. J. , Díaz H. , Cáceres A. , Carrer H. F.
Published: January 2005

In sexually segregated cultures of dissociated neurons taken from ventromedial hypothalamus of rat fetuses at embryonic day 16 (E16), it is demonstrated that only neurons from males respond with increased axonal growth to the addition of 17‐β‐estradiol 100 nM (E2) to the culture medium. Moreover, this response is contingent upon co‐culture with heterotopic glia from a target region (amygdala), whereas in the presence of homotopic glia or in cultures without glia, E2 has no effect. It is concluded that before neurons are exposed to gonadal steroids in utero there is a sexual difference in the response to E2, probably explained by earlier maturation of neurons from males as compared to females. The possibility that the observed axogenic effect may be the consequence of an interaction among E2, cells equipped with specific receptors, and glia‐producing trophic factors is discussed. © 1995 Wiley‐Liss, Inc.
Widespread expression of the peripheral myelin protein‐22 gene (pmp22) in neural and non‐neural tissues during murine development
Authors: Baechner D. , Liehr T. , Hameister H. , Altenberger H. , Grehl H. , Suter U. , Rautenstrauss B.
Published: January 2005

The gene encoding the peripheral myelin protein PMP22 is affected by various mutations in the hereditary peripheral neuropathies Charcot‐Marie‐Tooth disease type 1A (CMT1A), Déjérine‐Sottas syndrome (DSS) and hereditary neuropathy with liability to pressure palsies (HNPP). In contrast to the recent remarkable progress in the genetics of the PMP22 gene, the biological function of PMP22 remains largely unknown. In this report, we have confirmed by using in situ hybridization techniques that high levels of PMP22 niRNA are present in maturing peripheral nerves of the 2‐week‐old mouse, a finding consistent with the PNS‐specific defect observed in hereditary peripheral neuropathies. However, high levels of PMP22 transcripts were also found in the villi of the adult gut, and PMP22 expression was detected in various non‐neural tissues during embryonic mouse development. In early embryogenesis (9.5 days postconception, dpc), PMP22 RNA expression appears restricted to the epithelial ectodermal layer. During early organogenesis (11.5 dpc), particularly high levels of expression are present in the capsule surrounding the liver and in the forming gut, while low levels of PMP22 mRNA can be fund in precartilagous condensations forming the vertebrae and the ventricular layer of the myelencephalon. During midgestation development (14.5 dpc to 16.5 dpc), the number of PMP22‐positive tissues increases, and high expression is detected in several mesoderm‐derived tissues, in particular connective tissues of the face region, bones including the vertebrae, the lung mesenchym, and in muscles. In addition, high expression is also found in ectoderm‐derived tissues, especially the epithelia of the lens and the skin. These findings strongly suggest that PMP22 serves not only a PNSspecific function but is also of broader biological significance in cell proliferation and/or differentiation. ©1995 Wiley‐Liss, Inc.
Comparative distribution of GAD65 and GAD67 mRNAs and proteins in the rat spinal cord supports a differential regulation of these two glutamate decarboxylases in vivo
Authors: Feldblum S. , Dumoulin A. , Anoal M. , Sandillon F. , Privat A.
Published: January 2005

Gamma‐aminobutyric acid (GABA) synthesis can result from the action of at least two glutamic acid decarboxylase (GAD) isoforms, GAD65 and GAD67, possibly involved in distinct mechanisms. We have made the hypothesis that GAD65 may respond to short‐term changes and is present in neurons with a phasic activity, while GAD67 may rather provide GABA for the metabolic pool and for supporting tonic levels of synaptic transmission (Erlander et al.: Neuron 7:91–100, 1991; Feldblum et al.: J Neurosci Res 34:689–706, 1993). In the present work we have tested this hypothesis in the rat spinal cord where both types of activities have been identified. The correlation of GABA immunodetection with the distribution of GAD65 and GAD67 mRNAs and proteins has evinced in the dorsal horn a differential regulation of the two isoforms. In situ hybridization has revealed, in the dorsal horn, relatively higher levels of GAD67 mRNA than of GAD65, while immunodetection of the proteins demonstrated numerous punctate profiles with both GAD antisera. Reverse transcription‐polymerase chain reaction (RT‐PCR) data confirmed the abundance of the GAD67 transcripts compared to GAD65 in the rat spinal cord. In contrast, within the ventral horn, there was a greater number of GAD67‐immunoreactive (IR) profiles mostly located around motoneurons. The paucity of GAD65 immunoreactivity in the ventral horn cannot be related to a different accessibility of the antigens to the epitopes since on the same section a dense GAD65 staining was detected in the dorsal horn. Hence, a number of biochemical and electrophysiological data support the concept of the involvement of glycine as the major inhibitory system within the ventral horn which may explain the low levels of GAD transcription in this region. The paucity of GAD65 in the ventral horn may also reflect a functional difference, suggesting a predominance of GAD67 in neurons under tonic activity. In the dorsal horn, where neurons with phasic and tonic firing patterns have been disclosed, GAD65 may, in addition, provide GABA for responses to short‐term changes. ©1995 Wiley‐Liss, Inc.
Exogenous myelin basic protein promotes oligodendrocyte death via increased calcium influx
Authors: Tzeng S.‐F. , Deibler G. E. , DeVries G. H.
Published: January 2005

Treatment of cultured oligodendrocytes (OLGs) with micromolar quantities of myelin basic protein (MBP) caused a rapid, MBP‐dose dependent cell death. In contrast, a 72‐hr incubation of OLGs with MBP peptides (1–44, 47–87, 88–151, or 152–167) at comparable concentrations had no effect on cell viability. MBP and MBP peptides (1–44 and 88–151) have been shown to interact with ganglioside GM1 (Tzeng et al.: J Neurochem Res: 42:758–767, 1995). This interaction has been reported to increase calcium influx. Therefore, using the fluorescent dye Indo‐1 and an ACAS laser cytometer, we examined the level of intracellular calcium in OLGs after MBP treatment. MBP was shown to provoke a rapid, dramatic, and sustained rise of intracellular calcium in most OLGs. The levels of elevated intracellular calcium were sustained and did not return to baseline even after 10 min. This increase of intracellular calcium was suppressed in the presence of EGTA, indicating that the [Ca2+]i rise was due to the entry of extracellular calcium. Incubation of cultured OLGs with MBP peptides (1–44 or 88–151) caused a modest and transitory elevation of intracellular calcium ions in a lower percentage of OLGs. The potent OLG cytotoxicity of intact MBP and the loss of potency after proteolysis raise the possibility that MBP proteolysis during demyelination protects OLGs from death. ©1995 Wiley‐Liss, Inc.
Neurotransmitter synthesis by SN6 cell lines, a family of hybrid cell lines of embryonic septal origin
Authors: Gallyas F. , Satoh J. , Endoh M. , Kunishita T. , Tabira T.
Published: January 2005

Previously, we reported the presence of multiple neurotransmitters in subclones of SN6, a septal cholinergic hybrid cell line. To obtain information concerning the functionality of these transmitters, we measured transmitter contents, activities of transmitter‐producing enzymes, and the effect of serum‐free culture medium in two different batches (SN6.1.6 and SN6.10.2.2) and two subclones of the SN6 cell line (SN6.2a and SN6.1b). Except for SN6.1b, SN6 cell lines and subclones had basically the same neurotransmitter characteristics. Among the transmitters, only acetylcholine seemed to be functional. Monoamine oxidase was missing and activity of aromatic amino acid decarboxylase was diminished in SN6 cell lines. Even in serum‐containing medium, SN6.1b had a more mature morphology than the other cell lines, and it contained choline acetyltransferase and acetylcholine but not tyrosine hydroxylase or catecholamines. Similar characteristics were acquired by the mother cell line in response to serum‐free conditions. Thus, SN6.1b is the most mature of these central cholinergic neuronal cell lines, at least with regard to neurotransmitter profiles. ©1995 Wiley‐Liss, Inc.
Perinatal morphine II: Changes in cortical plasticity
Authors: Germani E. , Lesma E. , De Biasi S. , Di Giulio A. M. , Bertelli A. , Gorio A.
Published: January 2005

We have previously shown that perinatal exposure to morphine impairs reactive plasticity of serotonin (5‐HT) neurons following selective neonatal lesion (Gorio et al., J Neurosci Res 34:462–471, 1993). This study shows that morphine inhibits also that the compensatory sprouting of intact axons after partial denervation. Neonatal 6‐OHDA injection causes norepinephrine (NE) depletion in the frontal cortex, which triggers a compensatory increase of dopamine, serotonin (5‐HT), and met‐enkephalin content correlated by the increased density of tyrosine hydroxylase– and 5‐HT–positive axons. In perinatal morphine‐treated rats, no compensatory changes are observed after neonatal 6‐OHDA depletion of NE in the frontal cortex. ©1995 Wiley‐Liss, Inc.
Attenuation and recovery of nerve growth factor receptor mRNA in dorsal root ganglion neurons following axotomy
Authors: Krekoski C. A. , Parhad I. M. , Clark A. W.
Published: January 2005

The actions of nerve growth factor (NGF) are mediated by two receptor proteins, trk and p75. Recent evidence indicates that NGF upregulates the expression of both trk and p75 in responsive neurons including rat dorsal root ganglion (DRG) neurons. Axotomy by disconnecting the neuron from its source of target‐derived NGF is predicted to lead to the downregulation of trk and p75 expression. However, previous studies of the effects of axotomy on trk and p75 mRNA expression in rat DRG have yielded discrepant results. We report that following sciatic nerve crush, trk and p75 mRNA levels in L4‐L6 DRG decrease to ∼50% of control levels at 4–14 days, return to control levels by 30 days, and are increased by ∼30% at 60 days. Similar changes are observed following nerve transection although mRNA levels are slower in returning to normal and do not exceed control levels at later timepoints. Thus, trk and p75 expression decline early following target disconnection and later recover irrespective of target reinnervation. These observations indicate that target derived NGF is required for the maintenance of NGF receptor expression in adult rat DRG neurons and that non‐target derived factors can appropriate this function following peripheral nerve injury. © 1996 Wiley‐Liss, Inc.
OX‐40 antibody enhances for autoantigen specific Vβ8.2+ T cells within the spinal cord of lewis rats with autoimmune encephalomyelitis
Authors: Weinberg A. D. , Lemon M. , Jones A. J. , Vainiene M. , Celnik B. , Buenafe A. C. , Culbertson N. , Bakke A. , Vandenbark A. A. , Offner H.
Published: January 2005

The Vβ8.2 T cell receptor (TCR) component is the predominant Vβ gene product associated with antigen specific CD4+ T cell response to the major encephalitogenic epitope of myelin basic protein (MBP) in Lewis rats. Lewis rats were actively immunized with MBP in complete Freund's adjuvant and the Vβ8.2 positive and negative cells were analyzed for IFN‐γ mRNA production and OX‐40 cell surface expression during the onset of EAE. The Vβ8.2+ T cells isolated from the spinal cord produced the majority of mRNA for IFN‐γ and also showed a marked enhancement for OX‐40 expression compared to Vβ8.2+ T cells isolated from the lymph nodes. Only a fraction of IL‐2 receptor positive T cells examined ex vivo from the inflammatory compartments co‐expressed the OX‐40 antigen. These results suggested that OX‐40 cell surface expression could be used to identify and isolate the most recently activated T cells ex vivo. OX‐40+ T cells isolated from the spinal cord were highly enriched for the Vβ8.2 T cell receptor component compared to OX‐40− or unsorted spinal cord lymphocytes. OX‐40+ T cells isolated from the spinal cord had an enhanced response to MBP, whereas OX‐40+ cells isolated from the lymph nodes responded to both MBP and purified protein derivative. These data suggest that activated T cells can be isolated and characterized with the OX‐40 antibody which only respond to the antigens present at the local site. The data also imply that isolation of OX‐40+ T cells will be useful in identifying Vβ biases and autoantigen specific cells within inflamed tissues even when the antigen specificity is unknown. © 1996 Wiley‐Liss, Inc.

This article is a US Government work and, as such, is in the public domain in the United States of America
Methylphenylpyridium ion (MPP+) enhances glutamate‐induced cytotoxicity against dopaminergic neurons in cultured rat mesencephalon
Authors: Sawada H. , Shimohama S. , Tamura Y. , Kawamura T. , Akaike A. , Kimura J.
Published: January 2005

Parkinson's disease is characterized by chronic progression of dopaminergic neuronal death, the mechanism of which is still unknown. Although methyl‐4‐phenylpyridium ion (MPP+) or MPP+‐like substance, that can reduce mitochondrial complex I activity, is supposed to be a causative agent for Parkinson's disease, it is difficult to explain the chronic neuronal degeneration for years. It is important to identify other putative agents capable of causing chronic cell death besides MPP+. We hypothesized that treatment with small doses of MPP+, not causing severe damage to dopaminergic neurons but merely reducing the activity of mitochondrial complex I, can be a model of Parkinson's disease, and that glutamate can be a putative agent causing chronic neuronal degeneration. Using primary culture of the rat mesencephalon, we investigated glutamate‐induced cytotoxicity against dopaminergic and non‐dopaminergic neurons with or without the pretreatment with MPP+. Brief exposure to glutamate showed similar cytotoxicity against both dopaminergic and non‐dopaminergic neurons. An N‐methyl‐D‐aspartate receptor antagonist completely blocked the glutamate‐induced cytotoxicity against both dopaminergic and non‐dopaminergic neurons. In the dopaminergic neurons, MPP+ caused cytotoxicity that was not blocked by co‐administration of MK‐801. After pretreatment with small doses of MPP+, sub‐lethal doses of glutamate caused severe cell damage restricted to dopaminergic neurons, suggesting that MPP+ potentiates the glutamate‐induced cytotoxicity only against dopaminergic neurons. As glutamate is putatively capable of causing cytotoxicity against dopaminergic neurons, the present findings might be important in considering the pathogenesis of dopaminergic neuronal degeneration and a possible therapeutic application of glutamate receptor antagonists in Parkinson's disease. © 1996 Wiley‐Liss, Inc.
Alterations of dopamine release by rat caudate putamen tissues superfused with α2‐Macroglobulin
Authors: Hu Y.‐Q. , Liu B.‐J. , Dluzen D. E. , Koo P. H.
Published: January 2005

Monoamine‐activated alpha‐2‐macroglobulin (α2M) has been shown to decrease the dopamine concentrations in rat caudate putamen (CP) in vivo as well as inhibit choline acetyltransferase activities in the culture of basal forebrain neurons. In this study, we further investigated the effects of methylamine‐activated α2M (MA‐α2M) upon striatal rlopaminergic function by determining whether a direct infusion of this glycoprotein will alter dopamine (DA) release in vitro from superfused CP tissue fragments. In experiment 1, an infusion of 2.8 μM MA‐α2M produced a statistically significant increase in DA release compared with control superfusions. In experiment 2, varying doses (0, 0.7, 1.4, 2.8, 4.1 μM) of MA‐α2M were tested for their capacity to alter DA release. Only the 2.8 μM dose of MA‐α2M was effective in producing a significant increase of DA release. In experiment 3, the normal form of α2M (N‐α2M) at 2.8 μM was compared with the control superfusions. The infusion of N‐α2M produced an increase in DA release which was substantially lower than the DA increase induced by MA‐α2M, and not significantly different from that of the control superfusion. These results show that MA‐α2M, like some other neurotoxins, can markedly alter CP dapaminergic function as indicated by the acute increase in DA release following infusion of this glycoprotein, and these effects are exerted at a relatively narrow range of doses. Taken together, these data suggest that this glycoprotein, if allowed to accumulate in the central nervous system (CNS), may promote some neurodegenerative changes that can occur in disorders like Parkinson's disease. © 1996 Wiley‐Liss, Inc.
Disappearance of actin‐binding protein, drebrin, from hippocampal synapses in alzheimer's disease
Authors: Harigaya Y. , Shoji M. , Shirao T. , Hirai S.
Published: January 2005

The actin‐binding protein drebrin is localized in postsynaptic terminals in adult brain and is considered to be related to synaptic plasticity. Immunocytochemical study demonstrated that widespread drebrin immunoreactivity was observed in hippocampal formations of control human brains, while Alzheimer's disease (AD) brains showed remarkable reductions in this immunoreactivity. Western blot analysis demonstrated that drebrin E (116 kD) as well as drebrin A (125 kD) presented in adult human brains, and that these isoforms were decreased in parallel in AD brains. On the other hand, synaptic vesicle‐specific 38‐kD protein (SVP‐38), a presynaptic marker was not so changed in AD brains in comparison with control brains by both techniques. These findings suggest that drebrin E and A in the adult human brain may be co‐localized in postsynaptic terminals, and that drebrin may be more sensitive as a marker of synaptic damage than SVP‐38, and that the disappearance of drebrin may contribute to the pathogenesis of memory disturbance in AD. © 1996 Wiley‐Liss, Inc.
Identification and topography of neuronal cell populations expressing; TNFα and IL‐1α in response to hippocampal lesion
Authors: Tchélingérian J.‐L. , Le Saux F. , Jacque C.
Published: January 2005

In previous studies, we have shown that a traumatic lesion to the hippocampus of adult mice induces the transitory expression of TNFα and IL‐1α by neurons of different brain areas and also by glial cells at the site of injury. The aim of the present study was to establish whether the expression of TNFα and IL‐1α is restricted to defined subpopulations, or else is common to most of the central neuronal populations. Using polyclonal anti‐GAD 67, anti‐TH and monoclonal anti‐ChAT, and anti‐5‐HT antibodies in a double‐labeling immunohistochemical procedure in combination with murine anti‐TNFα and anti‐IL‐1α polyclonal antibodies, we show that most GABAergic, catecholaminergic, and serotoninergic neurons, and a subgroup of the cholinergic neurons, express these cytokines. Although not immunohistochemically characterized, neurons in some glutamatergic structures such as the hippocampus and the prefrontal cortex also express these cytokines. Thus, we conclude that the capacity of central neurons to express cytokines like TNFα and IL‐1α in reaction to a brain Injury is not restricted to peculiar neuronal subtypes, but could include most of the neuronal populations of the brain. © 1996 Wiley‐Liss, Inc.
Effects of MF‐268, a new cholinesterase inhibitor, on acetylcholine and biogenic amines in rat cortex
Authors: Zhu X.‐D. , Cuadra G. , Brufani M. , Maggi T. , Pagella P. G. , Williams E. , Giacobini E.
Published: January 2005

MF‐268 bitartrate [(3a S, 8a R)‐1,2,3,3a,8,8a‐hexahydro‐1,3a,8‐trimethylpyrrolo[2,3‐b]indol‐5‐ol[8‐(cis2, 6‐dimethyl‐morpholin‐4‐yl)octyl]‐carbamate L‐bitartrate hydrate; Mediolanum Farmaceutici, Milan, Italy] is a pseudo‐reversible carbamate‐type cholinesterase inhibitor (ChEI) which interacts with the catalytic and regulatory anionic site of the enzyme. Its effects on extracellular levels of acetylcholine (ACh), norepinephrine (NE), dopamine (DA), and serotonin (5‐HT, 5‐hydroxytryptamine) were studied in rat cortex by using a microdialysis technique coupled with high‐performance liquid chromatography‐electrochemical detection (HPLC‐ECD). Conscious, freely moving rats were systemically [per os (p.o.) and subcutaneously (s.c.)] administered MF‐268 with no ChEI in the probe. Cholinesterase inhibition in brain was assayed in parallel experiments.

Oral administration of MF‐268 (0.5, 2.0, and 5.0 mg/kg) produced a significant increase of extracellular ACh in cortex; the maximal increase was 300% [not significant (n.s.)], 460% and 1,200%, respectively. Maximal cholinesterase (ChE) inhibition was 2.3% (n.s.) at 9 hr and 9.7% (P < .05) at 12 hr after the 2.0 and 5.0 mg/kg doses, respectively. Norepi nephrine and DA levels were increased 180% and 100% after the 5.0 mg/kg dose, respectively; 100%, and 60% after the 2.0 mg/kg dose, respectively; and 70% for both amines after the 0.5 mg/kg dose, respectively. The elevation lasted at least 5 hr with the 2.0 and 5.0 mg/kg doses. There were no major changes in 5‐HT levels at these three doses.

Subcutaneous administration (0.5 and 2.0 mg/kg) produced a maximal 360% (5.5 hr) and 2,500% (5 hr) increase in extracellular ACh, respectively. Maximal ChE inhibition was 13% (0.5 mg/kg) and 41% (2.0 mg/kg). Neither 0.5 nor 2.0 mg/kg produced a consistent modification of NE. Only a transient increase in DA was seen with the 0.5 mg/kg dose. There were no changes in 5‐HT levels at these two doses. MF‐268‐treated animals showed slight cholinergic side effects (chewing, tremor) at both doses.

MF‐268 administered intracortically through the microdialysis probe at a concentration of 50 p.M induced a 5,900% increase in ACh levels at 6 hr. This effect started 30 min after injection and continued throughout the period of administration. MF‐268 produced a significant decrease in NE levels (−44%) starting at 30 min, and a slight but significant increase in DA levels of 45% at 2.5 hr. A significant increase of 5‐HT (58%) was also observed starting at 4 hr. Slight symptoms of cholinergic toxicity were observed during intracortical administration. © 1996 Wiley‐Liss, Inc.
Optimisation of processing conditions for infrared drying of cashew kernels with testa
Authors: Hebbar Umesh H , Ramesh MN
Published: January 2005

Cashew kernels are thermally processed to facilitate the removal of their outer skin (testa). Infrared (IR) processing of cashew kernels for differential drying is a novel approach. Processed cashew kernels are valued for their colour, size and texture. The kinetics of colour change and the effect of thermal processing on compressive strength (indicator of brittleness) during IR drying of cashew kernels were investigated. Kernels with testa were dried for different durations (15–55 min) over a range of temperatures (55–95 °C). The change in colour was expressed as total colour difference and browning index. The colour values increased with increasing drying temperature and duration, indicating darkening of the kernel colour. Increase in drying duration reduced the compressive strength, imparting the desired brittleness to the kernel. Optimisation of the drying conditions by response surface methodology and the peelability factor indicated that the best results could be obtained when cashew kernels were dried at 55 °C for 55 min. Copyright © 2004 Society of Chemical Industry
Oxidation studies with peroxomonophosphoric acid. II. A kinetic and mechanistic study of dimethyl sulfoxide oxidation in acid and alkaline media
Authors: Panigrahi G. P. , Panda Radhasyam
Published: January 2005

The kinetics of dimethyl sulfoxide (DMSO) oxidation by peroxomonophosphoric acid (PMPA) in aqueous medium at 308 K and I = 0.4 mol/dm3 follow the rate expressions
equation image
In the pH range from 0 to 2, where k1 and k2 are 5.092 × 10−1 dm3/mol sec and ≃ 0, respectively;
equation image
in the pH range from 4 to 7, where k2 = 8.127 × 10−3 and k3 = 2.90 × 10−3 dm3/mol sec; and
equation image
in the pH range from 10 to 13.6, where k4 ≃ 0, and k5 = 3.08 × 10−2 dm3/mol sec.

The reaction is interpreted in terms of mechanisms involving an electrophilic and a nucleophilic attack of the peroxomonophosphoric acid species, respectively, in acid and alkaline regions, on the sulfur atom of the sulfoxide molecule giving rise to S‐type transition states followed by oxygen‐oxygen bond fission to form the products.
Charcot on Parkinson's disease
Authors: Goetz Christopher G.
Published: January 2005

Charcot saluted Parkinson for his early observations, but condemned his use of the term “paralysis agitans.” He emphasized that patients were neither dramatically weak nor were they necessarily plagued with tremor. Charcot suggested the name “Parkinson's disease,” although he could not resist the comment in his amphitheater lecture series at the Salpětrièe that French physicians (unnamed) had probably described the disorder before 1817. Tremor, rigidity, postural instability, and bradykinesia were all recognized by Charcot. He classified the disorder as a “névrose,” meaning a neurologic disorder without a known pathologic lesion, and found little benefit from therapies available at the time, including belladonna and ergot products.
Pain in Parkinson's disease
Authors: Goetz Christopher G. , Tanner Caroline M. , Levy Mark , Wilson Robert S. , Garron David C.
Published: January 2005

We studied the prevalence and character of pain in Parkinson's disease (PD) and its association with motor fluctuations. Of 95 outpatients, 46% experienced pain they attributed to PD. Patients with pain were younger but no more disabled on objective motor scores than patients without pain. Musculoskeletal, dystonic, and join pains were most frequent. Painful episodes, especially musculoskeletal cramps, usually occurred when parkinsonian disability was maximal.