bluuebunny/crossref_metadata_2025 huggingface dataset:
Time‐course of modifications elicited by reserpine on the density and mRNA synthesis of the vesicular monoamine transporter, and on the density of the membrane dopamine uptake complex
Authors: Naudon L. , Leroux‐Nicollet I. , Raisman‐Vozari R. , Botton D. , Costentin J.
Published: December 2004

The long‐term effects of a unique injection of reserpine (5 mg/kg s.c.) on the vesicular monoamine transporter and dopamine uptake complex have been investigated, in parallel with behavioral and neurochemical effects. Early after treatment, a dramatic decrease in locomotor activity, as well as a marked depletion in striatal dopamine (DA), associated with a prominent enhancement in dopaminergic turnover were observed in reserpine‐treated rats. From 2 to 60 days after reserpine injection, a recovery in locomotor activity occurred, in parallel with an increased DA content in the striatum, reaching about 50% of controls at day 60. At this time, the dopamine turnover was quite normal. The density of the dopamine uptake sites in the striatum, studied with 3H GBR12783, was unchanged after reserpine treatment at any time studied up to 60 days. By contrast, the density of binding sites for 3H dihydrotetrabenazine (3H TBZOH), a marker for the vesicular monoamine transporter, remained dramatically decreased in the striatum all over the time of the study (> −90% of controls at day 2 and −80% at day 30 and 60). A lesser decrease (−60%) was observed in the substantia nigra pars compacta (SNc), 2 and 30 days after reserpine treatment. This suggests that at least 60% of the vesicular monoamine transporter is sensitive to reserpine in this cell bodies region, indicating that this proportion of the transporter is integrated in functional vesicles, a prerequisite for reserpine binding. On the other hand, in spite of profound modifications of DA levels and neuronal activity, induced by a persistent blockade of the vesicular uptake process, the density of mRNA encoding the vesicular monoamine transporter remained constant in the SNc from 2 to 60 days following reserpine injection. © 1995 Wiley‐Liss, Inc.
Subcellular localization of synaptophysin in noradrenergic nerve terminals: A biochemical and morphological study
Authors: Annaert Wim G. , Llona Isabel , De Ridder Erik , Weyns Andre , Quatacker Jos , De Potter Werner P.
Published: December 2004

The subcellular localization of synaptophysin was investigated in noradrenergic nerve terminals of bovine vas deferens and dog spleen and compared with membrane‐bound and soluble markers of noradrenergic storage vesicles. At the light microscopical level chromogranin A‐ and cytochrome b561‐ immunoreactivity revealed an identical and very dense innervation of the entire vas deferens. In the case of synaptophysin, most immunoreactivity was found only in the outmost varicosities closest to the lumen, which were also positive for chromogranin A. Small dense‐core vesicles of dog spleen were purified using a combination of velocity gradient centrifugation and size exclusion chromatography. Small dense‐core vesicles were enriched 64 times as measured by the noradrenaline content. Enrichments for dopamine‐β‐hydroxylase were in a similar range. Synaptophysin‐containing vesicles were smaller in size and they did not contain the typical noradrenergic markers dopamine‐β‐hydroxylase, cytochrome b561, and noradrenaline. Instead, they might store adenosine triphosphate (ATP). A greater part of synaptophysin immunoreactivity was consistently found at high sucrose densities at the position of large dense‐core vesicles. © 1995 Wiley‐Liss, Inc.

We conclude that in the noradrenergic nerve terminal: (1) small dense‐core vesicles have a membrane composition similar to large dense‐core vesicles, indicating that the former are derived from the latter; and (2) synaptophysin seems not to be present on small dense‐core vesicles. We suggest the possibility that synaptophysin‐containing vesicles form a residual population whose role in neurotransmission has been taken over by large and small densecore vesicles following noradrenergic differentiation.
Plastic effect of soiled bedding on the structure of synapses in rat accessory olfactory bulb
Authors: Ichikawa Masumi , Matsuoka Masato , Mori Yuji
Published: December 2004

The effects of exposure to soiled bedding on synaptic morphology in the accessory olfactory bulb (AOB) were examined in adult male rats. Forty‐day‐old male rats were isolated. One group was exposed to bedding soiled by male and female rats (EC). Another group was exposed only to male‐soiled bedding (SC). A third group was exposed to clean bedding (IC). After 2 months, the animals were sacrificed for electron microscopy. The size and the numerical density of synapses were measured in the glomerulus and the granule cell layer. In the glomerulus, the mean size of the synapses was significantly greater in the EC than in the IC group, whereas that in the SC group appeared to be intermediate between those in the EC and the IC groups but was not significantly different from those in the EC and the IC groups. There was no statistically significant difference in the density of synapses among the three groups. Synapses in the granule cell layer are classified into two types: (1) perforated synapses, which are characterized by discontinuities in their postsynaptic thickenings, and (2) nonperforated synapses. The mean size of perforated synapses was significantly greater in the EC than in the IC and SC groups; however, no statistically significant difference was observed in the size of nonperforated synapses among the three groups. Moreover, no statistically significant difference was observed in the numerical densities of either perforated or nonperforated synapses among the three groups. These results suggested that exposure to a more complex soiled bedding environment (i.e., to bedding soiled by both male and female rats) can induce greater structural changes of the synapses in the AoB of male adult rats. © 1995 Wiley‐Liss, Inc.
Electrochemical evidence of increased dopamine transmission in prefkontal cortex and nucleus accumbens elicited by ventral tegmental μ‐opioid receptor activation in freely behaving rats
Authors: Noel Miriam Beth , Gratton Alain
Published: December 2004

Chronoamperometry was used in combination with monoamine‐selective electrodes to monitor, in nucleus accumbens (NAcc) and prefrontal cortex (PFC) of freely behaving rats, changes in dopamine (DA)‐like electrochemical signals elicited by unilateral ventral tegmental microinjections of the selective μ‐opioid receptor agonist D‐Ma, N‐Me‐Phe‐Gly‐01‐Enkephalin (DAMGO; 0.01, 0.1, and 1.0 nmol). The results show that DAMGO dose‐dependently increased electrochemical signals both in NAcc and PFC within a few minutes of injection. While DAMGO elicited signal increases of comparable amplitudes in both regions, the increases recorded in PFC were significantly longer lasting than those in NAcc; at the highest dose tested (1.0 nmol), DAMGO produced signal increases that lasted (mean ± sem) 129 ± 7.3 min in PFC and 96 ± 12.5 min in NAcc. Pretreatment with the opioid receptor antagonist, naloxone (2 mgkg, sc), significantly attenuated the peak amplitude and reduced the duration of DAMGO‐in‐ duced (0.1 nmol) signal increases both in PFC and NAcc. In contrast, pretreatment with apomorphine (50 μg/kg, sc), a D1/D2 DA receptor agonist, significantly reduced the duration and the rate of rise of the signal increases in both regions but had little effect on the peak increases in signal. Unilateral ventral tegmental DAMGO administration (0.01, 0.1, and 1.0 nmol) also caused dose‐dependent increases in contraversive circling the duration of which approximated that of the signal increases recorded in NAcc. However, differences in the time courses of DAMGO‐induced contraversive circling and signal increases in NAcc suggest that the behavioral stimulant effect of ventral tegmental μ‐opioid receptor activation may not be mediated exclusively by meso‐NAcc DA neurons. The results of this study suggest that enkephalins modulate the activity of meso‐PFC DA neurons and that behaviorally relevant activation of μ‐opioid receptors in the ventral tegmental area increases DA transmission in PFC to a same, if not to a greater extent as in NAcc. These findings are discussed in relation to evidence indicating that the response of meso‐NAcc DA neurons to a variety of stimuli, including drugs of abuse, is indirectly regulated by a DA‐sensitive neurons in PFC. © 1995 Wiley‐Liss, Inc.
Elevations of nucleus accumbens dopamine and DOPAC levels during intravenous heroin self‐administration
Authors: Wise Roy A. , Leone Paola , Rivest Robert , Leeb Kira
Published: December 2004

Extracellular dopamine and DOPAC (3,4‐dihydroxyphenylacetic acid) levels in nucleus accumbens were sampled by microdialysis and quantified with high‐ performance liquid chromatography during intravenous heroin self‐administration sessions in rats. Dopamine levels in 10 and 20 min samples were elevated following the first injection of each session, reaching a plateau of elevation within the first two or three injections and falling back toward baseline only when drug access was terminated. Elevations were in the range of 150–300% when unit dosages of 0.05–0.2 mgkg were given. Increasing the work requirement from FR‐1 to FR‐10 did not appear to alter the degree of elevation of dopamine levels, and dopamine levels fell during extinction while lever‐pressing rates increased 20‐fold. While animals compensated for unit dose changes between 0.05 and 0.2 mg/kg/injection, adjusting their response rate such that the same hourly drug intake and the same asymptotic dopamine levels were maintained across these conditions, at 0.4 mg/kg/injection hourly drug intake and asymptotic dopamine levels were elevated beyond the levels sustained by the lower doses. These findings confirm that self‐administered doses of intravenous heroin are sufficient to activate the mesolimbic dopamine system and suggest that significant heroin “craving” can emerge when dopamine levels are still moderately elevated, long before the development of dopamine depletion associated with opiate withdrawal. © 1995 Wiley‐Liss, Inc.
CCKB receptors mediate CCK‐8S‐induced activation of dorsal hippocampus CA3 pyramidal neurons: An in vivo electrophysiological study in the rat
Authors: Gronier Benjamin , Debonnel Guy
Published: December 2004

The sulphated octapeptide C‐terminal fragment of cholecystokinin (CCK‐8s) is present in high concentration in the mammalian brain, where it acts via two types of receptor denoted CCKA, and CCKB. In the dorsal hippocampus, CCK‐8S exerts a potent excitatory effect on pyramidal neurons. The present electrophysiological study was undertaken to determine which CCK receptor type mediates this neuronal activation. Using in vivo extracellular unitary recordings of CA3 pyramidal hippocampal neurons, we compared the effect of SNF‐8702, a potent selective CCKB receptor agonist, to that of CCK‐BS, and assessed the effects of selective CCKA, and CCKB, antagonists. CCK‐8S and SNF‐8702, microiontophoretically applied on the same neurons produced a similar degree and pattern of activation. Both CCK‐8s‐ and SNF‐8702‐induced activations were suppressed by the microiontophoretic application of the CCKB antagonist CI‐988, but not by that of the CCKA, antagonist SR 27897. CCK‐8s‐induced activation was not significantly modified by the intravenous administration of the CCK, antagonists devazepide and SR 27897. However, it was reduced by the CCKB antagonist PD 135158, administered intravenously or intracerebroventricularly, and by the intravenous administration of the CCK, antagonist L‐365,260. The intravenous administration of PD 135158 also reduced SNF‐8702‐induced activations. These results indicate that CCKB, receptors mediate CC K‐8S‐induced activation of rat CA3 pyramidal neurons. © 1995 Wiley‐Liss, Inc.
Superoxide radicals mediate the biochemical effects of methylenedioxymethamphetamine (MDMA): Evidence from using CuZn‐superoxide dismutase transgenic mice
Authors: Cadet Jean Lud , Ladenheim Bruce , Hirata Hiroshi , Rothman Richard B. , Ali Syed , Carlson Elaine , Epstein Charles , Moran Timothy H.
Published: December 2004

The subacute and long‐term biochemical effects of methylenedioxymeth‐amphetamine (MDMA) were assessed in homozygous and heterozygous transgenic (Tg) mice that carry the complete sequence of the human copper‐zinc (CuZn) superoxide dismutase (SOD) gene. Non‐transgenic (Non‐Tg) mice showed significant decreased in striatal dopamine (DA) and dihydroxyphenylacetic acid (DOPAC) levels both at 24 h and at 2 weeks after a single injection of MDMA (50 mg/kg). Heterozygous SOD‐Tg mice showed DA depletion only at the 24 h time point. In contrast, homozygous SOD‐Tg mice show no DA or DOPAC depletion at either the 24 h or at the 2 week time points. Moreover, three injections of MDMA (50 mg/kg) given 24 h apart also caused marked reduction of striatal DA and DOPAC in Non‐Tg mice when these substances were measured 2 weeks after the last MDMA injection. That injection schedule also caused small decreases in DA levels in the heterozygous animals but no changes in the homozygous mice; DOPAC levels were not affected in the heterozygous nor in the homozygous SOD‐Tg mice. Furthermore, the multiple injection schedule caused significant decreases in DA and DOPAC in female Non‐Tg mice but not in the two strains of transgenic mice. Neither the single dose nor the multiple dose schedule of MDMA injections affected striatal serotonin (5‐HT) and 5‐hydroxyindoleacetic acid (5‐HIM)levels in any of the three strains of mice. These results support previous observations that MDMA‐induced biochemical effects are observed in the DA systems of mice, whereas these effects are seen in the 5‐HT systems of rats. The present observations also document for the first time a role for the production of superoxide radicals in these effects of MDMA. These mice are an important tool for dissecting pathways involved in drug‐induced neurotoxicity. © 1995 Wiley‐Liss, Inc.1

This article is a US Government work and, as such, is in the public domain in the United States of America.
Spare receptors and intrinsic activity: Studies with D1 dopamine receptor agonists
Authors: Watts Val J. , Lawler Cindy P. , Gonzales Andrea J. , Zhou Qun‐Yong , Civelli Olmer , Nichols David E. , Mailman Richard B.
Published: December 2004

The intrinsic activities of selected dopamine D1 receptor agonists were compared in three distinct molecular expression systems, C‐6, Ltk, and GH4, cells transfected with primate D1A receptors. The influence of the cell expression system on intrinsic activity varied markedly among agonists. Dihydrexidine (DHX), a potent full agonist with dramatic antiparkinsonian actions, displayed intrinsic activity similar to dopamine in all three cell lines. In contrast, SKF82958 and SKF38393 (full and partial agonists, respectively, in rat striatum) had intrinsic activities equal to dopamine in GH4, cells that expressed a high density of D1 receptors, yet were of lower intrinsic activity in C‐6 cells having 15‐fold fewer receptors. The idea that spare receptors are one important determinant of observed intrinsic activity was explored directly by “receptor titration”, in which ca. 90% of D1 receptors in Ltk cells were inactivated using EEDQ, an irreversible antagonist. Whereas EEDQ pretreatment decreased the potency of all agonists, it changed the intrinsic activity of some, but not all, drugs. A 40% decrease was seen with the partial agonist SKF38393, and, surprisingly, a 30% decrease was seen with the purported full agonist SKF82958. Conversely, the intrinsic activity of DHX and A68930 were unaffected by the EEDQ treatment. The data demonstrate that significant and biologically meaningful differences in intrinsic efficacy (e.g., DHX vs. SKF82958) may be obscured in test systems that have sufficient receptor reserve (e.g., the striatum). Such differences in intrinsic efficacy may be an important predictor of the clinical utility of D1 agonists. © 1995 Wiley‐Liss, Inc.
From ion currents to genomic analysis: Recent advances in GABAA receptor research
Authors: Rabow Lois E. , Russek Shelley J. , Farb David H.
Published: December 2004

The γ‐aminobutyric acid type A (GABAA) receptor represents an elementary switching mechanism integral to the functioning of the central nervous system and a locus for the action of many mood‐and emotion‐altering agents such as benzodiazepines, barbiturates, steroids, and alcohol. Anxiety, sleep disorders, and convulsive disorders have been effectively treated with therapeutic agents that enhance the action of GABA at the GABAA receptor or increase the concentration of GABA in nervous tissue. The GABAA receptor is a multimeric membrane‐spanning ligand‐gated ion channel that admits chloride upon binding of the neurotransmitter GABA and is modulated by many endogenous and therapeutically important agents. Since GABA is the major inhibitory neurotransmitter in the CNS, modulation of its response has profound implications for brain functioning. The GABAA receptor is virtually the only site of action for the centrally acting benzodiazepines, the most widely prescribed of the anti‐anxiety medications. Increasing evidence points to an important role for GABA in epilepsy and various neuropsychiatric disorders. Recent advances in molecular biology and complementary information derived from pharmacology, biochemistry, electrophysiology, anatomy and cell biology, and behavior have led to a phenomenal growth in our understanding of the structure, function, regulation, and evolution of the GABAA receptor. Benzodiazepines, barbiturates, steroids, polyvalent cations, and ethanol act as positive or negative modulators of receptor function. The description of a receptor gene superfamily comprising the subunits of the GABAA, nicotinic acetylcholine, and glycine receptors has led to a new way of thinking about gene expression and receptor assembly in the nervous system. Seventeen genetically distinct subunit subtypes (αl‐α6, βl‐β4, γl‐γ4,δ, pl‐p2) and alternatively spliced variants contribute to the molecular architecture of the GABAA receptor. Mysteriously, certain preferred combinations of subunits, most notably the αlβ2γ2 arrangement, are widely codistributed, while the expression of other subunits, such as βl or α6, is severely restricted to specific neurons in the hippocampal formation or cerebellar cortex. Nervous tissue has the capacity to exert control over receptor number, allosteric uncoupling, subunit mRNA levels, and posttranslational modifications.
Sensitivity of rat frontal cortical neurones to nicotine is increased by chronic administration of nicotine and by lesions of the nucleus basalis magnocellularis: Comparison with numbers of [3H]nicotine binding sites
Authors: Abdulla Fuad A. , Calaminici Mariarita , Wonnacott Sue , Gray Jeffrey A. , Stephenson John D. , Sinden John D.
Published: December 2004

The effects of chronic nicotine treatment and of unilateral AMPA lesion of the nucleus basalis magnocellularis (nbm) on the sensitivity of frontal cortical neurones to iontophoretically applied nicotine were studied. Chronic nicotine treatment increased the number of L3H1nicotine binding sites from 2.9 to 3.9 pmolg−1 wet weight, and increased the proportion of cortical neurones responding to nicotine from 32.3% to 60.0%. After unilateral nbm lesions, the densities of AChE‐positive fibers and [3H]nicotine binding sites were reduced by approximately 97% and 55%, respectively, and the proportion of neurones responding to nicotine increased from 32.3% to 53.8%. The two treatments, chronic nicotine administration and nbm lesion, also increased the size of individual neuronal responses, prolonged their duration, and shortened the response latency. Responses to glutamate were unaffected by either procedures. The results show that the increase in [3H]nicotine binding produced by chronic nicotine administration is associated with an increased response to iontophoretically applied nicotine, suggesting that the receptor upregulation induced by the chronic treatment were functional. Less easily explained is the association between increased sensitivity of frontal cortical neurons to nicotine after nbm lesion with a decreased receptor density. It is suggested that a substantial proportion of nicotinic receptors are located presynaptically, and that their loss after lesion concealed an upregulation at postsynaptic sites. © 1995 Wiley‐Liss, Inc.
Biochemical actions of chronic ethanol exposure in the mesolimbic dopamine system
Authors: Ortiz Jordi , Fitzgerald Lawrence W. , Charlton Maura , Lane Sarah , Trevisan Louis , Guitart Xavier , Shoemaker William , Duman Ronald S. , Nestler Eric J.
Published: December 2004

In previous studies, we have demonstrated that chronic administration of morphine or cocaine produces some common biochemical adaptations in the ventral tegmental area (VTA) and nucleus accumbens (NAc), components of the mesolimbic dopamine system implicated in the reinforcing actions of these and other drugs of abuse. Since this neural pathway is also implicated in the reinforcing actions of ethanol, it was of interest to determine whether chronic ethanol exposure results in similar biochemical adaptations. Indeed, as seen for chronic morphine and cocaine treatments, we show here that chronic ethanol treatment increased levels of tyrosine hydroxylase and glial fibrillary acidic protein immunoreactivity, and decreases levels of neurofilament protein immunoreactivity, in the VTA. Also like morphine and cocaine, ethanol increases levels of cyclic AMP‐dependent protein kinase activity in the NAc. These actions of ethanol required long‐term exposure to the drug, and were in most cases not seen in the substantia nigra or caudate‐putamen, components of the nigrostriatal dopamine system studied for comparison.

Altered levels of tyrosine hydroxylase in catecholaminergic cells frequently reflect altered states of activation of the cells. Moreover, increasing evidence indicates that ethanol produces many of its acute effects on the brain by regulating NMDA glutamate and GABA receptors. We therefore examined the influence of chronic ethanol treatment on levels of expression of specific glutamate and GABA receptor subunits in the VTA. It was found that long‐term, but not short‐term, ethanol exposure increased levels of immunoreactivity of the NMDARl subunit, an obligatory component of NMDA glutamate receptors, and of the Glu Rl subunit, a component of many AMPA glutamate receptors; but at the same time, long‐term ethanol exposure decreased immunoreactivity levels of the α1 subunit of the GABAA receptor complex. These changes are consistent with an increased state of activation of VTA neurons inferred from the observed increase intyrosine hydroxylase (TH) expression.

These results demonstrate that chronic ethanol exposure results in several biochemical adaptations in the mesolimbic dopamine system, which may underlie prominent changes in the structural and functional properties of this neural pathway related to alcohol abuse and alcoholism. © 1995 Wiley‐Liss, Inc.
Interhemispheric modulation of dopamine receptor interactions in unilateral 6‐OHDA rodent model
Authors: Lawler Cindy P. , Gilmore John H. , Watts Val J. , Walker Q. David , Southerland Stan B. , Cook Larry L. , Mathis Chet A. , Mailman Richard B.
Published: December 2004

A critical assumption in the unilateral 6‐hydroxydopamine (6‐OHDA) model is that interactions between the intact and denervated hemispheres do not influence the response to insult. The present study examined this issue by assessing the effects of unilateral substantia nigra 6‐OHDA lesions in rats that previously had received corpus callosum transections, a treatment designed to minimize interhemispheric influences. Quantitative autoradiography in the caudate‐putamen ipsilateral to the lesion revealed that corpus callosum transection did not alter the increase in D2‐like receptors ([125I]‐epidepride‐labeled sites) that is induced by unilateral 6‐OHDA lesion. There were no effects of either 6‐OHDA lesion or transection on D1 receptor density ([l25I]‐SCH23982 autoradiography). As a functional endpoint, dopamine‐stimulated cAMP efflux was measured in superfused striatal slices. In this paradigm, the net effect of dopamine (DA) represents a combination of D1 receptor‐mediated stimulation and D2 receptor‐mediated inhibition. 6‐OHDA lesion increased cAMP efflux induced by exposure to 100 p.M DA alone; corpus callosum transection did not alter this effect. An interaction between 6‐OHDA lesion and transection status was revealed, however, by comparison of results obtained with DA alone vs. DA plus the D2 antagonist sulpiride (to block the D2 inhibitory effects of 100 p.M DA). This comparison revealed two important effects of 6‐OHDA lesion in rats with an intact corpus callosum: (1)a moderate decrease in dopamine Dl receptor‐mediated stimulation; and (2) a dramatic decrease in the ability of D2 receptors to inhibit this stimulation. Corpus callosum transection prevented these effects of 6‐OHDA. These results provide a biochemical demonstration of D1:D2 receptor uncoupling in unilateral 6‐OHDA lesioned rats, and suggest that interhemispheric influences (e.g., contralateral cortico‐striatal glutamatergic projections) may contribute to lesion‐induced alterations in D1:D2 receptor interactions. © 1995 Wiley‐Liss, Inc.
Effects of coexisting neurochemicals on the release of serotonin from the intermediate area of rat thoracic spinal cord
Authors: Yang Ling , Helke Cinda J.
Published: December 2004

Serotonin (5‐HT), substance P (SP), neurokinin A (NKA), and thyrotropin‐releasing hormone (TRH) coexist in the nerve terminals of the intermediolateral cell column (IML) of the thoracic spinal cord. The Ca2+‐dependent release of 5‐HT from the microdissected intermediate area (including the IML) of the rat thoracic spinal cord, and the 5‐HT1B autoreceptor regulator of 5‐HT release, were previously demonstrated. In this paper, the effects of SP, NKA, TRH, and/or their analogs on the release of [3H]5‐HT from the intermediate area were investigated using an in vitro superfusion system. Both SP (the endogenous ligand for neurokinin‐1 (NK1) receptor) and an NK1, agonist (GR 73632) significantly increased the basal release of [33H]5‐HT. SP and GR 73632 did not change the K+‐stimulated release of [3H]5‐HT. The effect of the NK1 agonist on the basal release of [3H]5‐HT was dose‐dependent, was reduced by an NK1 antagonist (GR 82334), and was not dependent on extracellular Ca2+. Neither NKA, an NK2, agonist (GR 64349), nor a TRH analog (MK‐771) altered the basal or stimulated release of [3H]5‐HT. These data suggest that basal release of 5‐HT from the intermediate area of the rat thoracic spinal cord is regulated by SP (acting through an NK1 receptor), but not by NKA or TRH. These results provide evidence for the role of SP as a modulator of serotoninergic neurons in the intermediate area of the thoracic spinal cord, and may help to clarify the role of coexisting neurochemicals in the spinal regulation of the sympathetic nervous system. © 1995 Wiley‐Liss, Inc.

This article is a US Government work and, as such, is in the public domain in the United States of America.
N‐methyl‐D‐aspartate acutely increases proenkephalin mRNA in the rat striatum
Authors: Beckstead R. M.
Published: December 2004

Studies in which glutamate (GLU) neurotransmission has been reduced at striatal synapses have shown that GLU influences the biosynthesis of certain peptide cotransmitters by striatal neurons. The present experiment was designed to test the effects of direct activation of the NMDA or AMPA types of GLU receptor on the levels of two mRNAs that encode the peptide cotransmitters met5‐enkephalin (ME) and sub‐ stance P (SP). In situ hybridization histochemistry of forebrain tissue sections from rats 8 h after a single intracerebroventricular infusion of NMDA or AMPA revealed a significant and dose‐dependent elevation (to a maximum of almost 50%) of striatal ME mRNA when compared to vehicle‐injected controls. SP mRNA was not significantly affected. NMDA was more effective than AMPA over the dose range used. Pretreatment with a potent and highly specific AMPA antagonist (NBQX) predictably blocked the AMPA‐mediated elevation, and was only slightly effective against the NMDA‐induced response. In striking contrast, pretreatment with a potent and highly selective NMDA antagonist (CGP37849) fully opposed both the NMDA‐ and the AMPA‐mediated elevation of ME mRNA. These data further implicate the NMDA receptor in the regulation of peptide cotransmitter gene transcription. They suggest also that the AMPA receptor may play an indirect, synergistic role in the genetic responses of striatal neurons to GLU transmission. © 1995 Wiley‐Liss, Inc.
Mapping dopamine transporters in the human brain with novel selective cocaine analog [125I]RTI‐121
Authors: Staley J. K. , Boja J. W. , Carroll F. I. , Seltzman H. H. , Wyrick C. D. , Lewin A. H. , Abraham P. , Mash D. C.
Published: December 2004

The novel cocaine analog RTI‐121[3β‐(4‐iodophenyl)tropane‐2β‐carboxylic acid isopropyl ester] was evaluated as a probe for the in vitro labeling and localization of the dopamine transporter in the human brain. Saturation binding experiments conducted in sucrose‐phosphate buffer (10 mM sodium phosphate, pH 7.4, 0.32 M sucrose) revealed high‐ and low‐affinity binding components with affinity values (KD) of 0.25 ± 0.04 and 4.9 ± 1.6 nM (mean ± SE) and densities (Bmax) of 56.8 ± 13.8 and 147.7 ± 23.4 pmol/g tissue, respectively. In contrast, when saturation binding experiments were performed in phosphate‐buffered saline (10 mM Na2HP04, 1.8 mM KH2Po4, 136 mM NaCl,2.8 mM KC1, 10 mM NaI, pH 7.4), a 9‐fold decrease in the density of the low‐affinity component was noted, suggesting that the low‐affinity RTI‐121 binding site is associated with the region of the transporter involved in the ionic dependence of substrate recognition andor uptake. The rank order. of potency for inhibition of [1251]RTI‐121 binding to human caudate membranes demonstrates that the radioligand selectively labels the dopamine transporter (GBR 12909 > RTI‐121 > mazindol > nomifensine > (−)cocaine > desipramine > citalopram). Autoradiograpliic mapping of [1251]RTI‐121 revealed very high densities of cocaine recognition sites over areas known to be rich in dopaminergic innervation, including the caudate, putamen, and nucleus accumbens. Moderate densities were also observed over the substantia nigra and the ventral tegmental area. Low‐to‐background labeling of [1251]RTI‐ 121 was seen throughout the cerebral cortex, amygdaloid nuclei, globus pallidus, and thalamus. In comparison with the autoradiographic distribution of the cocaine analogs L3H1WIN 35,428 (or CFT) and [1251]RTI‐55 (or β‐CIT), the labeling pattern for [1251]RTI‐121 was more restricted. These studies demonstrate that [1251]RTI‐121 labels dopamine‐rich brain regions with greater selectivity than other currently available cocaine analogs, which makes it a potentially superior imaging probe for mapping the dopamine transporter in the human brain. © 1995 WiIey‐Liss, Inc.
Prenatal diagnosis of severe structural congenital malformations in Europe
Authors: Garne E. , Loane M. , Dolk H. , De Vigan C. , Scarano G. , Tucker D. , Stoll C. , Gener B. , Pierini A. , Nelen V. , Rösch C. , Gillerot Y. , Feijoo M. , Tincheva R. , Queisser‐Luft A. , Addor M.‐C. , Mosquera C. , Gatt M. , Barisic I.
Published: December 2004

Objectives

To assess at a population‐based level the frequency with which severe structural congenital malformations are detected prenatally in Europe and the gestational age at detection, and to describe regional variation in these indicators.

Methods

In the period 1995–1999, data were obtained from 17 European population‐based registries of congenital malformations (EUROCAT). Included were all live births, fetal deaths and terminations of pregnancy diagnosed with one or more of the following malformations: anencephalus, encephalocele, spina bifida, hydrocephalus, transposition of great arteries, hypoplastic left heart, limb reduction defect, bilateral renal agenesis, diaphragmatic hernia, omphalocele and gastroschisis.

Results

The 17 registries reported 4366 cases diagnosed with the 11 severe structural malformations and of these 2300 were live births (53%), 181 were fetal deaths (4%) and 1863 were terminations of pregnancy (43%); in 22 cases pregnancy outcome was unknown. The overall prenatal detection rate was 64% (range, 25–88% across regions). The proportion of terminations of pregnancy varied between regions from 15% to 59% of all cases. Gestational age at discovery for prenatally diagnosed cases was less than 24 weeks for 68% (range, 36–88%) of cases. There was a significant relationship between high prenatal detection rate and early diagnosis (P < 0.0001). For individual malformations, the prenatal detection rate was highest for anencephalus (469/498, 94%) and lowest for transposition of the great arteries (89/324, 27%). Termination of pregnancy was performed in more than half of the prenatally diagnosed cases, except for those with transposition of the great arteries, diaphragmatic hernia and gastroschisis, in which 30–40% of the pregnancies with a prenatal diagnosis were terminated.

Conclusion

European countries currently vary widely in the provision and uptake of prenatal screening and its quality, as well as the ‘culture’ in terms of decision to continue the pregnancy. This inevitably contributes to variation between countries in perinatal and infant mortality and in childhood prevalence and cost to health services of congenital anomalies. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Difficult early sonographic diagnosis of absence of the fetal septum pellucidum
Authors: Pilu G. , Tani G. , Carletti A. , Malaigia S. , Ghi T. , Rizzo N.
Published: December 2004

Standard sonographic views of the brain obtained along the axial planes at mid‐gestation failed to identify absence of the septum pellucidum in two consecutive fetuses. It was presumably the close proximity of the walls of the lateral ventricles that generated an artifact resembling a normal cavum septi pellucidi. In one of these fetuses, septo‐optic dysplasia was confirmed by magnetic resonance demonstration of hypoplastic optic tracts. In the other fetus, isolated absence of the septum pellucidum was the final diagnosis. Standard axial scans are unreliable in predicting absence of the septum pellucidum in the mid‐trimester fetus when the lateral ventricles are normal in size. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Cervical length as a prognostic factor for preterm delivery in twin‐to‐twin transfusion syndrome treated by fetoscopic laser coagulation of chorionic plate anastomoses
Authors: Robyr R. , Boulvain M. , Lewi L. , Huber A. , Hecher K. , Deprest J. , Ville Y.
Published: December 2004

Objective

To evaluate the risk of spontaneous preterm delivery in relation to cervical length in severe cases of twin‐to‐twin transfusion syndrome (TTTS) diagnosed before 26 weeks of gestation and treated by laser coagulation of the intertwin placental anastomoses.

Methods

This was an observational study of cases of severe TTTS diagnosed before 26 weeks of gestation and treated by fetoscopic laser coagulation between January 2002 and December 2003 in three centers. Laser was the first‐line treatment in all cases. Elective preterm deliveries before 34 weeks' for maternal or fetal indications, including intrauterine death of both fetuses, were excluded. Transvaginal sonographic measurement of cervical length prior to laser treatment and other risk factors of preterm delivery were evaluated by univariate and logistic regression analysis.

Results

Among the 137 women included, the mean cervical length was 32 and 38 mm in women delivering before and at or after 34 weeks, respectively (P < 0.001). For a cervical length of < 30 mm, the risk of delivery before 34 weeks was 74%. Severity of the disease, deepest vertical pool of amniotic fluid and amniotic fluid volume drained after the procedure were not associated with preterm delivery. Logistic regression analysis identified three independent factors to predict preterm delivery: short cervical length (increased risk), parity (increased risk) and intrauterine death of one twin (decreased risk).

Conclusion

In TTTS treated by laser, without indications for elective preterm birth, cervical length before treatment is significantly associated with gestational age at delivery, and this is independent of parity, intrauterine death of one fetus and other risk factors. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Beziehungen zwischen Lumineszenzspektrum und Struktur von Seltenerdkomplexen. I. Quadratisch‐antiprismatisch koordinierte Pyridin‐N‐Oxid‐Komplexe des Europium(III)
Authors: Butter E. , Seifert W.
Published: December 2004

Aus dem Lumineszenzspektrum der festen Komplexe Eu(pyO)8X3 (X = Cl−, Br−, J−, ClO) wurden nach der Methode der äquivalenten Operatoren die Parameter B für 1 = 2 und 4 berechnet. Aufspaltungsenergien und Intensitätsverhältnisse stimmen mit dem Vorliegen einer in Richtung D2d gestörten D4d‐Symmetrie (quadratisches Antiprisma) überein. Die axialen Parameter B werden jedoch stark durch das Potential der Anionen beeinflußt und sind dadurch zur Abschätzung des θ‐Winkels nicht unmittelbar brauchbar.
Über Na5[Fe(CN)5SO3]. Eigenschaften und Untersuchung des Zerfalls in wäßriger Lösung
Authors: Baran Enrique J. , Müller Achim
Published: December 2004

Es werden verschiedene Eigenschaften von Na5[Fe(CN)5SO3] beschrieben. Die Untersuchung der Zersetzung in Wasser ergab, daß nach einer Protonierung der Sulfitogruppe ein Austausch von SO3H− gegen H2O erfolgt. Die kinetische Messung zeigte, daß die Protonierung sehr viel schneller als der Austausch erfolgt und die letztere Reaktion nach einem Gesetz erster Ordnung abläuft. Die Geschwindigkeitskonstante für den Austausch von SO3H− gegen H2O ergab sich zu 0,0029 ± 0,0002 min−1 für t = 20°C.

Die Elektronenspektren von Na5[Fe(CN)5SO3] sowie weiterer Prussiate wurden gemessen und unter Anwendung der Ligandenfeldtheorie diskutiert.
Übergangsmetallchalkogenverbindungen. Über Bariumnitridoosmat (VIII)
Authors: Müller A. , Bollmann F. , Krebs B.
Published: December 2004

Darstellung und Eigenschaften von Ba(OsO3N)2 werden beschrieben. Die Verbindung kristallisiert in der Raumgruppe D–Pnma oder C–Pna21 mit Z = 4 und den Zellkonstanten a = 11,34 ± 0,03, b = 4,63 ± 0,01 und c = 13,62 ± 0,03 Å (Dx = 5,97 g/cm3). Das IR‐Spektrum zeigt im Valenzschwingungsbereich 7 von 8 nach der Faktorgruppe D2h zu erwartende Absorptionsbanden. Das Elektronenspektrum in Reflexion entspricht dem des Kaliumsalzes.
Übergangsmetallchalkogenverbindungen. Zur Kenntnis von Ba5(ReO6)2 und Ba3(ReO5)2
Authors: Baran Enrique J.
Published: December 2004

Die IR‐Spektren von Ba5(ReO6)2 und Ba3(ReO5)2 werden gemessen und diskutiert. Für Ba5(ReO6)2 läßt sich das Vorliegen von ReO6‐Gruppen im Gitter wahrscheinlich machen. Weiterhin werden die Elektronenspektren der Salze vermessen und teilweise zugeordnet. Bei den ermittelten Banden handelt es sich um „charge transfer”︁ Übergänge O → Re. Die Bindungsverhältnisse im Perrhenat, Meso‐ und Orthoperrhenat werden diskutiert.
Über Oxidsysteme mit Übergangsmetallionen in verschiedenen Oxydationsstufen. VIII. Über die Festkörperreaktionen von Cadmiumoxid mit den Vanadinoxiden VO, V2O3 und VO2
Authors: Reuter Bertold , Müller Klaus
Published: December 2004

Es wurden die Reaktionen von CdO mit VO, V2O3 und VO2 bei 700°C untersucht und als stabile Phasen der Spinell CdV2O4 und die Cadmiumvanadate(IV), CdVO3 und CdV3O7, beobachtet, von denen das letztere noch nicht bekannt war. Für den normalen Cadmium‐vanadin(III)‐Spinell wurde die Gitterkonstante zu a = 8,696 ± 0,001 Å bestimmt. Die d‐Werte und Absorptionsbanden im IR werden für die Verbindungen angegeben. Kristallchemische und elektronische Eigenschaften zeigen, daß im System Cd(CdxVV)O4 die Spinellphase bereits bei x ≈ 0,02 ihre obere Phasengrenze besitzt.
Untersuchungen an Selen‐Verbindungen. IL. Die RAMAN‐ und IR‐Spektren des Bis‐(trimethylsilyl)‐selenits und des Bis‐(trimethylsilyl)‐selenats
Authors: Paetzold R. , Knaust D.
Published: December 2004

Die Darstellung und einige Eigenschaften des Bis‐(trimethylsilyl)‐selenits werden beschrieben. Vom Bis‐(trimethylsilyl)‐selenit und‐selenat werden die RAMAN‐und IR‐Spektren mitgeteilt, zugeordnet und in Verbindung mit den Spektren der Alkylester der selenigen Säure und Selensäure diskutiert.
Untersuchungen an Selen‐Verbindungen. L. Donator‐Akzeptor‐Komplexe von Dimethylselenoxid mit Metallperchloraten
Authors: Paetzold R. , Bochmann G.
Published: December 2004

Durch Umsetzung von (CH3)2SeO mit den Metallperchloraten M(ClO4)2 (M = Mn, Co, Ni, Cu, Zn, Cd, Mg), M(ClO4)3 (M = Cr, Fe), AgClO4 und UO2(ClO4)2 wurden die folgenden Komplexe isoliert [(CH3)2SeO  DMSeO]: [M(DMSeO)6](ClO4)2 (M = Mn, Co, Ni, Zn, Cd, Mg); [M(DMSeO)6](ClO4)3 (M = Cr, Fe); [Cu(DMSeO)4](ClO4)2; [Ag(DMSeO)2]ClO4 und [UO2(DMSeO)5](ClO4)2. Aus den IR‐Spektren folgt für alle Komplexe koordinative Bindung des DMSeO über den Sauerstoff. Es wurden die magnetischen Momente der Cr‐, Mn‐, Fe‐, Co‐, Ni‐ und Cu‐Komplexe ermittelt sowie die Elektronen‐Reflexionsspektren aufgenommen. Daraus konnten strukturelle Angaben gewonnen werden. Aus den Elektonenspektren wurden die Dq‐ und B‐Werte abgeleitet und das DMSeO in die spektrochemische und nephelauxetische Reihe eingeordnet.
The effect of Thermal Pre‐treatment on the Reactivity of Fe2O3
Authors: Solymosi F. , Jáky K. , Szabó Z. G.
Published: December 2004

The effect of thermal pre‐treatment of iron(III) oxides on thier reactivity has been studied together with the studies of some of their physical properties.

Cadmium ferrite formation slightly increased when the iron(III) oxide was sintered between 550 and 680°C and markedly decreased above 700°C. The effect of thermal pretreatment appeared more pronouncedly when reactions were carried out at the temperature of the sintering. Between 550 and 750°C the highest conversion was found when iron(III) oxide was sintered and brought into reaction at about 700°C. The reactivity of iron(III) oxide was investigated also in other reactions: solubility in HCl and catalytic decomposition of H2O2.

On the basis of density and electric conductivity data the high reactivity of Fe2O3 exhibited between 675 and 700°C was interpreted by the great increase of iron vacancies.
Extraction of Np(IV) by some oxygen‐containing solvents
Authors: Abdel‐Gawad A. S. , Shehata M. K. , El‐Naggar H. A.
Published: December 2004

Extraction of Np(IV) from aqueous nitrate medium with some mono‐alcohols, ethers and ketones has been investigated. Similarities and qualitative features of the extraction process are discussed.
Sättigungsdrucke, Bildungsenthalpien von WOBr4 und WO2Br2, die Reaktionsgleichgewichte 2WO2Br2 = WO3 + WOBr4 und 2WOBr4 + SiO2 = 2WO2Br2 + SiBr4
Authors: Oppermann H. , Stöver G.
Published: December 2004

Die Sättigungsdrucke von WOBr4, und WO2Br2 und die Reaktionsgleichgewichte wurden im Membrannullmanometer bzw. durch Ampullenabschreckversuche bestimmt. Aus der Temperaturabhängigkeit der Sättigungsdrucke wurden ΔH° (subl., WOBr4, 298) = 29,4 (±1) kcal/Mol, ΔH° (subl., WO2Br2, 298) = 36,6 (±1,5) kcal/Mol und Δ S° (subl., WOBr4, 298) = 50,1(±1) cl sowie Δ S° (subl., WO2Br2, 298) = 53,0 (±1,5) cl berechnet. Für die Zersetzung des festen WO2Br2 gewinnt man Δ H° (R, f, 690) = 37,5 (±0,7) kcal und Δ S° (R, f, 690) = 49,0 (±0,5) cl, für die Zersetzung des gasförmigen WO2Br2 sind Δ H° (R, g, 690) = −29,6 (±2) kcal und Δ S° (R, g, 690) = −44,5 (±1,5) cl. Aus der Reaktion des WOBr4 mit SiO2 wurden die Reaktionsenthalpie Δ H° (R, 923) = 46,6 (±1) kcal und die Reaktionsentropie Δ S° (R, 923) = 44 (±1) cl gewonnen. Die Auswertung der Reaktionsgleichgewichte ergibt die Abschätzung der Standardentropien für WOBr4 und WO2Br2 mit S° (WOBr4, f, 298) = 62 (±6) cl und S° (WO2Br2, f, 298) = = 38 (±3) cl.
Osmium(III)‐jodid
Authors: Schäfer Harald , Huneke Karl‐Heinz , Brendel Claus
Published: December 2004

Durch Umsetzung von OsCl4 mit HJ wird OsJ3 gewonnen. Die Verbindung wird analytisch, durch thermischen Abbau, magnetisch und röntgenographisch charakterisiert. OsJ3 kristallisiert im TiJ3‐Typ.

Die von Fergusson, Robinson und Roper1) beschriebenen Jodide OsJ2 und OsJ sind Gemenge von OsJ3 mit OsO2 (bzw. OsO2 · 2H2O).
Beitrag zur Reaktion zwischen Nickel(II)‐oxid und Eisen(III)‐oxid zu molarem Nickelferrit
Authors: Heinke H. , Kleinert P.
Published: December 2004

Mit Hilfe mehrerer Meßmethoden (Sättigungsmagnetisierung, paramagnetische Suszeptibilität, spezifische Oberfläche, spezifische katalytische Aktivität, Debye‐Scherrer‐Aufnahmen) wurde die Bildung des molaren Nickelferrits, NiFe2O4, nach der Reaktion NiO + Fe2O3 = NiFe2O4 studiert. Durch Vergleich der Methoden untereinander sollten einige im Prozeß der Ferritbildung auftretende Probleme, z. B. das Verhältnis zwischen der benötigten Energiemenge bei der Ferritbildung und der Ausbeute an Endprodukt, geklärt werden. Dabei wurden sowohl kinetische als auch thermodynamische Berechnungen angestellt und deren Ergebnisse anhand der Literatur diskutiert.
Stickstoff‐Komplexe von Barium, Strontium und Calcium
Authors: Linke K.‐H. , Taubert R.
Published: December 2004

Bei der unvollständigen solvolytischen Zersetzung der Erdalkalipernitride Me3N4 (Me = Ba, Sr, Ca) mit Wasser, wasserfreier Essigsäure oder absolutem Hydrazin entstehen Substanzen, die als Erdalkali‐Stickstoff‐Komplexe aufzufassen sind. Hierfür sprechen neben der quantitativen Analyse der Solvolyseprodukte vor allem die Ergebnisse der IR‐spektroskopischen Untersuchungen. Aus der Absorption der N  N‐Valenzschwingung wurden Bindungsgrad und Bindungslänge der NN‐Bindung in der koordinierten N2‐Molekel bei den verschiedenen N2‐Komplexen näherungsweise bestimmt.
Derivatographische Untersuchungen an einem basischen Kobaltcarbonat
Authors: Avramov L. , Betschev Chr.
Published: December 2004

Die thermische Zersetzung von CoCO3 · Co(OH)2 · (H2O)0,5 wurde im Temperaturabereich von 20 bis 600°C an der Luft sowie (dynamisch) in einer Stickstoffatmosphäre mittels TGA, DTA, chemischer Analyse und Röntgenbeugung untersucht. Der Ablauf der Zersetzung in N2 unterscheidet sich vollkommen von dem an der Luft, die Reaktion hat mehrere Stufen. Es wird der wahrscheinlichste Zersetzungsmechanismus vorgeschlagen und eine Deutung der verschiedene n Erscheinungen gegeben.
Beiträge zur Chemie der selteneren Elemente. LXVII*)1). Infrarotabsorptionsspektren von amorphem und kristallinem ScPO42
Authors: Muck A. , Petrů F.
Published: December 2004

Die IR‐Absorptionsspektren des hydratisierten und wasserfreien amorphen und des kristallinen Scandiumphosphats, ScPO4 wurden im Bereich 400–4000 cm−1 (nach der KBr‐Methode) untersucht. Die Messungen wurden bei Raumtemperatur an vorher bei 20–1100°C getemperten Proben vorgenommen. Dadurch konnten der Verlauf der Dehydratisierung des amorphen Phosphats sowie die Kristallisation des wasserfreien Salzes verfolgt werden. Im amorphen wasserfreien Phosphat weist das Anion PO43− die Symmetrie C3v auf, während das kristallisierte wasserfreien Salz eine site‐Symmetric Vd des Anions besitzt. Das IR‐Spektrum des wasserfreien kristallinen ScPO4 gehört zu der Gruppe des Xenotim‐Typus, welche eine der beiden Gruppen der Spektren von wasserfreien Phosphaten der Metalle der Seltenen Erden darstellt.
Zur Gitterabmessung von Eisen‐Thiospinell, Fe2S4
Authors: Yamaguchi S. , Wada H.
Published: December 2004

Ein mechanisches Gemenge von Eisen‐Thiospinell und Magnetkies wurde auf hydrothermalem Wege hergestellt. Aus dem Elektronenbeugungsbild dieses Gemenges wurde die Gitterabmessung von Eisen‐Thiospinell zu a0 = 9,875 ± 0,003 ÅE bei ca. 40°C (bezogen auf die von Magnetkies) bestimmt.