The α<Subscript>1</Subscript>,α<Subscript>2</Subscript>, and α<Subscript>3</Subscript> Subunits of GABA<Subscript>A</Subscript> Receptors: Comparison in Seizure-Prone and -Resistant Mice and during Development

Gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter in brain, opens chloride channels through actions on GABAA receptors. We now report base and amino acid sequences of the alpha 1, alpha 2, and alpha 3 subunits from GABAA receptors of audiogenic seizure-prone (DBA/2J) and -resistant (C57BL/6J) inbred strains of mice. Inbreeding had fixed different alleles of the alpha 1 subunit in the two strains, giving five base differences in the cDNAs. None of these affected amino acid sequence, but one did create a NsiI restriction site potentially useful in mapping genomic DNA. No base or amino acid sequence differences between the strains were detected for the other two subunits. Northern blots revealed no apparent strain differences in message levels for these three subunits in whole brains of the mice at 3 weeks of age, the peak of seizure susceptibility in DBA/2J, but did reveal distinct regional and developmental patterns of expression among the subunits in mouse brain.     

5-HTR<Subscript>2A</Subscript> and 5-HTR<Subscript>3A</Subscript> but not 5-HTR<Subscript>1A</Subscript> antagonism impairs the cross-modal reactivation of deprived visual cortex in adulthood

Visual cortical areas show enhanced tactile responses in blind individuals, resulting in improved behavioral performance. Induction of unilateral vision loss in adult mice, by monocular enucleation (ME), is a validated model for such cross-modal brain plasticity. A delayed whisker-driven take-over of the medial monocular zone of the visual cortex is preceded by so-called unimodal plasticity, involving the potentiation of the spared-eye inputs in the binocular cortical territory. Full reactivation of the sensory-deprived contralateral visual cortex is accomplished by 7 weeks post-injury. Serotonin (5-HT) is known to modulate sensory information processing and integration, but its impact on cortical reorganization after sensory loss, remains largely unexplored. To address this issue, we assessed the involvement of 5-HT in ME-induced cross-modal plasticity and the 5-HT receptor (5-HTR) subtype used. We first focused on establishing the impact of ME on the total 5-HT concentration measured in the visual cortex and in the somatosensory barrel field. Next, the changes in expression as a function of post-ME recovery time of the monoamine transporter 2 (vMAT2), which loads 5-HT into presynaptic vesicles, and of the 5-HTR_1A and 5-HTR_3A were assessed, in order to link these temporal expression profiles to the different types of cortical plasticity induced by ME. In order to accurately pinpoint which 5-HTR exactly mediates ME-induced cross-modal plasticity, we pharmacologically antagonized the 5-HTR_1A, 5-HTR_2A and 5-HTR_3A subtypes. This study reveals brain region-specific alterations in total 5-HT concentration, time-dependent modulations in vMAT2, 5-HTR_1A and 5-HTR_3A protein expression and 5-HTR antagonist-specific effects on the post-ME plasticity phenomena. Together, our results confirm a role for 5-HTR_1A in the early phase of binocular visual cortex plasticity and suggest an involvement of 5-HTR_2A and 5-HTR_3A but not 5-HTR_1A during the late cross-modal recruitment of the medial monocular visual cortex. These insights contribute to the general understanding of 5-HT function in cortical plasticity and may encourage the search for improved rehabilitation strategies to compensate for sensory loss.     

CHA<Subscript>2</Subscript>DS<Subscript>2</Subscript>-VASc score and prognosis in ischemic strokes with atrial fibrillation

The CHA₂DS₂-VASc score was developed to improve stroke risk stratification in atrial fibrillation (AF) patients. We sought to analyze the distribution and prognostic value of the CHA₂DS₂-VASc score in a cohort of ischemic stroke patients with AF. In total, 439 consecutive stroke patients with AF were studied. The CHA₂DS₂-VASc score was calculated according to clinical status before stroke onset. Poor outcome was defined as a modified Rankin score of 3 to 6 at 3 months. Association between CHA₂DS₂-VASc score and poor outcome was analyzed using logistic regression analysis. In 95.6% of patients, CHA₂DS₂-VASc was >1 and only 41.8% of those with previously diagnosed AF were using oral anticoagulation at the time of the stroke. Poor outcome was found in 53.1% of the patients. In univariate analysis age, female sex, current smoking, previous stroke, CHA₂DS₂-VASc score, and stroke severity were associated with outcome. In multivariate analysis, CHA₂DS₂-VASc score was independently associated with poor outcome [OR 1.36 (95% CI: 1.14–1.62), P = 0.001] as well as NIHSS [OR 1.22 (95% CI: 1.17–1.26), P < 0.001]. After removing stroke severity, therapeutic anticoagulation was also associated with stroke prognosis [OR 0.45 (95% CI: 0.23–0.86), P = 0.016]. Most patients with ischemic stroke and AF have a high CHA₂DS₂-VASc score. Independent of stroke severity, CHA₂DS₂-VASc score is associated with 3-month outcome. Despite all the available information and guidelines, our AF patients are clearly undertreated.     

Presence of D<Subscript>1</Subscript>- and D<Subscript>2</Subscript>-like dopamine receptors in the rat,mouse and bovine multiciliated ependyma

Summary The multiciliated ependyma forms an epithelial-like layer that could act as a selective barrier between the brain parenchyma and cerebrospinal fluid. In the present study, tyrosine hydroxylase-containing fibres have been detected in the basal pole of the ependymal cells of the lateral ventricles of rat, mouse and calf. The use of antibodies against at least two different peptide sequences of each D₂, D₃, D₄ and D₅ dopamine receptor subtype has allowed their detection in: (i) sections of mouse, rat and bovine lateral ventricles, by means of immunocytochemistry; and (ii) membrane protein extracts obtained from the ependymal layer of the bovine lateral ventricles, using immunoblotting. The immunocytochemical study has shown the presence of all these subtypes of dopamine receptors in the ependymal cells. Immunoblotting demonstrated similar immunoreactive bands for all receptor subtypes in both ependymal and corpus striatum membrane extracts.     

Evaluation of the Profile and Mechanism of Neurotoxicity of Water-Soluble [Cu(P)<Subscript>4</Subscript>]PF<Subscript>6</Subscript> and [Au(P)<Subscript>4</Subscript>]PF<Subscript>6</Subscript> (P = thp or PTA) Anticancer Complexes

[Cu(thp)₄]PF₆, [Cu(PTA)₄]PF₆, [Au(thp)₄]PF₆ and [Au(PTA)₄]PF₆ are phosphane (thp = tris(hydroxymethyl)phosphane; PTA = 1,3,5-triaza-7-phosphaadamantane) copper(I) and gold(I) water-soluble complexes characterized by high anticancer activity in a wide range of solid tumors, often able to overcome drug resistance of platinum-based compounds. For these reasons, they have been proposed as a valid alternative to platinum-based chemotherapeutic drugs (e.g., cisplatin and oxaliplatin). In vitro experiments performed on organotypic cultures of dorsal root ganglia (DRG) from 15-day-old rat embryos revealed that copper-based compounds were not neurotoxic even at concentrations higher than the IC₅₀ obtained in human cancer cells while [Au(PTA)₄]PF₆ was neurotoxic at lower concentration than IC₅₀ in cancer cell lines. The ability of these compounds to hinder the proteasome machinery in DRG neurons was tested by fluorimetric assay showing that the non-neurotoxic copper-based complexes do not inhibit proteasome activity in DRG primary neuron cultures. On the contrary, the neurotoxic complex [Au(PTA)₄]PF₆, induced a significant inhibition of proteasome activity even at concentrations lower than the IC₅₀ in cancer cells. The proteasome inhibition induced by [Au(PTA)₄]PF₆ was associated with a significant increase in α-tubulin polymerization that was not observed following the treatment with copper-based compounds. Uptake experiments performed by atomic absorption spectrometry showed that both copper-based complexes and [Au(PTA)₄]PF₆ are internalized in neuron cultures. In vitro and in vivo preliminary data confirmed copper-based complexes as the most promising compounds, not only for their anticancer activity but also concerning the peripheral neurotoxicity profile.     

Modulation of Postnatal Neurogenesis by Perinatal Asphyxia: Effect of D<Subscript>1</Subscript> and D<Subscript>2</Subscript> Dopamine Receptor Agonists

Perinatal asphyxia (PA) is associated to delayed cell death, affecting neurocircuitries of basal ganglia and hippocampus, and long-term neuropsychiatric disabilities. Several compensatory mechanisms have been suggested to take place, including cell proliferation and neurogenesis. There is evidence that PA can increase postnatal neurogenesis in hippocampus and subventricular zone (SVZ), modulated by dopamine, by still unclear mechanisms. We have studied here the effect of selective dopamine receptor agonists on cell death, cell proliferation and neurogenesis in organotypic cultures from control and asphyxia-exposed rats. Hippocampus and SVZ sampled at 1–3 postnatal days were cultured for 20–21 days. At day in vitro (DIV) 19, cultures were treated either with SKF38393 (10 and 100 µM, a D₁ agonist), quinpirole (10 µM, a D₂ agonist) or sulpiride (10 μM, a D₂ antagonist) + quinpirole (10 μM) and BrdU (10 μM, a mitosis marker) for 24 h. At DIV 20–21, cultures were processed for immunocytochemistry for microtubule-associated protein-2 (MAP-2, a neuronal marker), and BrdU, evaluated by confocal microscopy. Some cultures were analysed for cell viability at DIV 20–21 (LIVE/DEAD kit). PA increased cell death, cell proliferation and neurogenesis in hippocampus and SVZ cultures. The increase in cell death, but not in cell proliferation, was inhibited by both SKF38393 and quinpirole treatment. Neurogenesis was increased by quinpirole, but only in hippocampus, in cultures from both asphyxia-exposed and control-animals, effect that was antagonised by sulpiride, leading to the conclusion that dopamine modulates neurogenesis in hippocampus, mainly via D₂ receptors.     

Utility of measuring vitamin B<Subscript>12</Subscript> and its active fraction,holotranscobalamin, in neurological vitamin B<Subscript>12</Subscript> deficiency syndromes

Vitamin B₁₂ (VitB₁₂, cobalamin) deficiency has been associated with various neuropsychiatric conditions, such as peripheral neuropathy, subacute combined degeneration, affective disorders, and cognitive impairment. Current assays analyze vitamin B₁₂, of which only a small percentage is metabolically active. Measurement of its active fraction, holotranscobalamin, might be of greater relevance, but data in populations with neuropsychiatric populations are lacking. In this study, in order to validate VitB₁₂ and holotranscobalamin (holoTC) serum levels for the detection of VitB₁₂ deficiency in neuropsychiatric conditions, we compared the validity of VitB₁₂ and holoTC in a patient cohort with neuropsychiatric conditions suspicious for VitB₁₂ deficiency. The cohort included all patients admitted to the Department of Neurology at our university between 2005 and 2009 with at least two parameters of the VitB₁₂ metabolism available (n = 1,279). We used elevated methylmalonic acid as the external validation criterion for VitB₁₂ deficiency and restricted our analyses to subjects with normal renal function. Among all normal renal function patients, 13.2% had VitB₁₂ deficiency. In receiver operating characteristic curve (ROC) analysis, correlation of VitB₁₂ and holoTC with vitamin B₁₂ deficiency was generally weak, and the areas under the curve (AUC) were not significantly different for holoTC compared to vitamin B₁₂ in all subjects (AUC: 0.66 [95%CI: 0.51–0.82]; p = 0.04 vs. 0.72 [0.65–0.78], p < 0.0001) and in subcohorts of patients with classical VitB₁₂ deficiency syndromes. The positive predictive values for holoTC and vitamin B₁₂ were low (14.7 vs. 21.0%) and both were associated with more false-positive than true-positive test results. holoTC does not show superior diagnostic accuracy compared to VitB₁₂ for the detection of VitB₁₂ deficiency in subjects with neuropsychiatric conditions. Neither test can be recommended to diagnose VitB₁₂ deficiency in subjects with neuropsychiatric disorders.     

The effects of alpha-tocoferol and H<Subscript>2</Subscript>O<Subscript>2</Subscript> on the mitochondrial membrane potential and Bax/Bcl-xL ratio in PC12 cells

Using the flow-cytometry method, we demonstrated the ability of alpha-tocopherol (alpha-T) at nano- and micromolar concentrations to recover the mitochondrial membrane potential (ΔΨm), which decreased after H₂O₂ treatment in PC12 neuronal line cells. Alterations in the ΔΨm in PC12 cells were evaluated using the fluorescent probe tetramethylrhodamine (TMRM). The higher cell-fluorescence intensity corresponded to a higher ΔΨm value. Treatment with H₂O₂ resulted in a decrease in the fluorescence intensity from 100% in the control to 43.2 ± 5.1% (p < 0.001). Long-term 18-h preincubation with 100 nM or 100 μM alpha-T increased the fluorescence intensity in PC12 cells from 43.2 ± 5.2% up to 88.4 ± 4.8 and 89.6 ± 6.5% of the control value, respectively (p < 0.01 according to the one-way analysis of variances). Alpha-T at both 100 nM and 100 μM concentrations significantly and with similar efficacy decreased the ratio of the proapoptotic protein Bax to the antiapoptotic protein Bcl-xL (Bax/Bcl-xL) in the control PC12 cells. However, we did not reveal any significant effect of H₂O₂ or preincubation with alpha-T on this ratio in PC12 lysates. Furthermore, H₂O₂ increased both the Bax and Bcl-xL levels in PC12 cells.     

sPhospholipase A<Subscript>2</Subscript> is inhibited by anthocyanidins

Epidemiological studies suggest that nutritional antioxidants may reduce the incidence of neurodegenerative disorders and age-related cognitive decline. Specifically, protection against oxidative stress and inflammation has served as a rationale for promoting diets rich in vegetables and fruits. The present study addresses secretory phospholipase A₂ (sPLA₂) as a novel candidate effector of neuroprotection conferred by anthocyanins and anthocyanidins. Using a photometric assay, 15 compounds were screened for their ability to inhibit PLA₂. Of these, cyanidin, malvidin, peonidin, petunidin, and delphinidin achieved K _i values ≤18 μM, suggesting a modulatory role for berry polyphenols in phospholipid metabolism.     

ORL<Subscript>1</Subscript> Activation Mediates a Novel ORL<Subscript>1</Subscript> Receptor Agonist SCH221510 Analgesia in Neuropathic Pain in Rats

The molecular technology known as clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) is revolutionizing the field of medical research and deepening our understanding of numerous biological processes. The attraction of CRISPR/Cas9 lies in its ability to efficiently edit DNA or modulate gene expression in living eukaryotic cells and organisms, a technology that was once considered either too expensive or scientifically risky. CRISPR/Cas9 has been successfully applied in agriculture to develop the next generation of disease-resistant plants. Now, the capability of gene editing has been translated to the biomedical area, focusing on the future of medicine faced with drug-resistant microbes by selectively targeting genes involved in antibiotic resistance, for example, or finding the ultimate strategy for cancer or HIV. In this regard, it was recently demonstrated that an injection of cancer-fighting CRISPR-modified white blood cells in a patient suffering from metastatic lung cancer could lead to promising results. Researchers and bioethicists are debating questions about the regulation of CRISPR/Cas9 that must be addressed. While legal challenges surround the use of this technique for genetically modifying cell lines in humans, we review the basic understanding of CRISPR/Cas9 and discuss how this technology could represent a candidate for treatment of non-communicable diseases in nutrition, such as obesity.     

Dopamine D<Subscript>2</Subscript> agonist priming in intact and dopamine-lesioned rats

Receptor priming is a recently discovered phenomenon by which receptor agonists produce abrupt and long-lived supersensitization of receptors. Induction of dopamine (DA) D2 receptor supersensitivity by the agonist quinpirole was discovered approximately 15 years ago, and was found to occur consistently if rats were treated repeatedly at daily or weekly or monthly intervals with low or high doses of quinpirole. In this review we summarize and discuss some of the major studies that underlie DA D2 receptor supersen-sitivity, describe behavioral processes that are known to be altered by DA D2 receptor supersensitivity, and discuss the importance of DA innervation on expression of enhanced behaviors. DA D2 receptor supersen-sitivity represents one of the neural mechanisms implicated in psychiatric disorders. Also, DA D₂ receptor supersensitivity and increased DA D₃ receptor expression are associated with motor dyskinesias, as in L-DOPA-treated Parkinson’s disease patients. An understanding of receptor priming, a knowledge of the types of behavioral expression associated with DA D₂ receptor supersensitivity, and an understanding of mechanisms associated with receptor supersen-sitization, can lead to improvements in the treatments of psychiatric and neurological disorders.     

Orexins/Hypocretins Acting at G<Subscript>i</Subscript> Protein-Coupled OX<Subscript>2</Subscript> Receptors Inhibit Cyclic AMP Synthesis in the Primary Neuronal Cultures

Orexins A and B are newly discovered neuropeptides with pleiotropic activity. They signal through two G protein-coupled receptors: OX₁ and OX₂. In this study, we examined the expression of orexin receptors and effects of the receptors’ activation on cyclic AMP formation in the primary neuronal cell cultures from rat cerebral cortex. Both types of orexin receptors were expressed in rat cortical neurons; the level of OX₂R was markedly higher compared to OX₁R. Orexin A (an agonist of OX₁R and OX₂R) and [Ala¹¹-D-Leu¹⁵]orexin B (a selective agonist of OX₂R) did not affect basal cyclic AMP formation in the primary neuronal cell cultures. Both peptides (0.001–1 μM) inhibited, in a concentration-dependent manner and IC₅₀ values in low nanomolar range, the increase in the nucleotide production evoked by forskolin (1 μM; a direct activator of adenylyl cyclase), pituitary adenylate cyclase-activating polypeptide (PACAP27; 0.1 μM), and vasoactive intestinal peptide (VIP; 3 μM). Effects of orexin A on forskolin-, PACAP27-, and VIP-stimulated cyclic AMP synthesis were blocked by TCS OX2 29 (a selective antagonist of OX₂R), and unaffected by SB 408124 (a selective antagonist of OX₁R). Pretreatment of neuronal cell cultures with pertussis toxin (PTX) abolished the inhibitory action of orexin A on forskolin- and PACAP-stimulated cyclic AMP accumulation. It is suggested that in cultured rat cortical neurons orexins, acting at OX₂ receptors coupled to PTX-sensitive G_i protein, inhibit cyclic AMP synthesis.     

Evaluation of the Protective Effects of Sarains on H<Subscript>2</Subscript>O<Subscript>2</Subscript>-Induced Mitochondrial Dysfunction and Oxidative Stress in SH-SY5Y Neuroblastoma Cells

Sarains are diamide alkaloids isolated from the Mediterranean sponge Haliclona (Rhizoniera) sarai that have previously shown antibacterial, insecticidal and anti-fouling activities. In this study, we examined for the first time the neuroprotective effects of sarains 1, 2 and A against oxidative stress in a human neuronal model. SH-SY5Y cells were co-incubated with sarains at concentrations ranging from 0.01 to 10 μM, and the well-known oxidant hydrogen peroxide at 150 μM for 6 h and the protective effects of the compounds were evaluated. Among the sarains tested, sarain A was the most promising compound, improving mitochondrial function and decreasing reactive oxygen species levels in human neuroblastoma cells treated with the compound at 0.01, 0.1 and 1 μM. This compound was also able to increase the activity of the antioxidant enzymes superoxide dismutases by inducing the translocation of the nuclear factor E2-related factor 2 (Nrf2) to the nucleus at the lower concentrations tested (0.01 and 0.1 μM). Moreover, sarain A at 0.1 and 1 μM blocked the mitochondrial permeability transition pore (mPTP) opening through cyclophilin D inhibition. These results suggest that the protective effects produced by the treatment with sarain A are related with its ability to block the mPTP and to enhance the Nrf2 pathway, indicating that sarain A may be a candidate compound for further studies in neurodegenerative diseases.     

Antisecretory Factor Modulates GABA<Subscript>A</Subscript> Receptor Activity in Neurons

The antisecretory factor is an endogenous protein found in all mammalian tissues investigated so far. It acts by counteracting intestinal hypersecretion and various forms of inflammation, but the detailed mechanism of antisecretory factor (AF) action is unknown. We tested neuronal GABA_A receptors by means of AF-16, a potent AF peptide derived from amino acids 36–51 from the NH₂ part of AF. Cultured rat cerebellar granule cells were used, and the effects on the GABA-mediated chloride currents were determined by whole-cell patch clamp. Both the neurotransmitter GABA and AF-16 were added by perfusion of the experimental system. A 3-min AF-16 preincubation was more efficacious than 30 s in significantly elevating the rapidly desensitizing GABA-activated chloride current. No effect was found on the tonic, slowly desensitizing current. The GABA-activated current increase by AF-16 demonstrated a low k of 41 pM with a maximal increase of 37% persisting for some minutes after AF washout, independent from GABA concentration. This indicates an effect on the maximal stimulation (E%_Max) excluding an altered affinity between GABA and its receptor. An immunocytochemical fluorescence approach with anti γ2 subunit antibodies demonstrated an increased expression of GABA_A receptors. Thus, both the electrophysiological and the immunofluorescence approach indicate an increased appearance of GABA_A receptors on the neuronal membrane. The rationale of the experiments was to test the effect of AF on a defined neuronal population of GABA_A receptors. The implications of the results on the impact of AF on the enteric nervous system or on brain function are discussed.     

The Neuropeptide Orexin-A Inhibits the GABA<Subscript>A</Subscript> Receptor by PKC and Ca<Superscript>2+</Superscript>/CaMKII-Dependent Phosphorylation of Its β<Subscript>1</Subscript> Subunit

Orexin-A and orexin-B (Ox-A, Ox-B) are neuropeptides produced by a small number of neurons that originate in the hypothalamus and project widely in the brain. Only discovered in 1998, the orexins are already known to regulate several behaviours. Most prominently, they help to stabilise the waking state, a role with demonstrated significance in the clinical management of narcolepsy and insomnia. Orexins bind to G-protein-coupled receptors (predominantly postsynaptic) of two subtypes, OX₁R and OX₂R. The primary effect of Ox-OXR binding is a direct depolarising influence mediated by cell membrane cation channels, but a wide variety of secondary effects, both pre- and postsynaptic, are also emerging. Given that inhibitory GABAergic neurons also influence orexin-regulated behaviours, crosstalk between the two systems is expected, but at the cellular level, little is known and possible mechanisms remain unidentified. Here, we have used an expression system approach to examine the feasibility, and nature, of possible postsynaptic crosstalk between Ox-A and the GABA_A receptor (GABA_AR), the brain’s main inhibitory neuroreceptor. When HEK293 cells transfected with OX₁R and the α₁, β₁, and γ_2S subunits of GABA_AR were exposed to Ox-A, GABA-induced currents were inhibited, in a calcium-dependent manner. This inhibition was associated with increased phosphorylation of the β₁ subunit of GABA_AR, and the inhibition could itself be attenuated by (1) kinase inhibitors (of protein kinase C and CaM kinase II) and (2) the mutation, to alanine, of serine 409 of the β₁ subunit, a site previously identified in phosphorylation-dependent regulation in other pathways. These results are the first to directly support the feasibility of postsynaptic crosstalk between Ox-A and GABA_AR, indicating a process in which Ox-A could promote phosphorylation of the β₁ subunit, reducing the GABA-induced, hyperpolarising current. In this model, Ox-A/GABA_AR crosstalk would cause the depolarising influence of Ox-A to be boosted, a type of positive feedback that could, for example, facilitate the ability to abruptly awake.     

GABA-B<Subscript>1</Subscript> Receptors are Coupled to the ERK1/2 MAP Kinase Pathway in the Absence of GABA-B<Subscript>2</Subscript> Subunits

In the current model of γ-aminobutyric acid (GABA) B receptor function, there is a requirement for GABA-B_1/2 heterodimerisation for targetting to the cell surface. However, different lines of evidence suggest that the GABA-B₁ subunit can form a functional receptor in the absence of GABA-B₂. We observed coupling of endogenous GABA-B₁ receptors in the DI-TNC1 glial cell line to the ERK pathway in response to baclofen even though these cells do not express GABA-B₂. GABA-B_1A receptors were also able to mediate a rapid, transient, and dose-dependent activation of the ERK1/2 MAP kinase pathway when transfected alone into HEK 293 cells. The response was abolished by G_i/o and MEK inhibition, potentiated by inhibitors of phospholipase C and protein kinase C and did not involve PI-3-kinase activity. Finally, using bioluminescence resonance energy transfer and co-immunoprecipitation, we show the existence of homodimeric GABA-B_1A receptors in transfected HEK293 cells. Altogether, our observations show that GABA-B_1A receptors are able to activate the ERK1/2 pathway despite the absence of surface targetting partner GABA-B₂ in both HEK 293 cells and the DI-TNC1 cell line. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Relation between lipoprotein-associated phospholipase A<Subscript>2</Subscript> mass and incident ischemic stroke severity

Background

Manifestations of ischemic stroke vary widely, and serum biomarkers may be useful for stratification of risk of severe stroke. This study evaluated the association of lipoprotein-associated phospholipase A₂ (Lp-PLA₂) mass and initial severity.

Methods

We employed a retrospective analysis on our hospital-based registry and recruited 488 first-onset ischemic stroke patients admitted within 24 h after onset and with Lp-PLA₂ mass measured. Stroke severities evaluated by National Institutes of Health Stroke Scale (NIHSS) were compared between Lp-PLA₂ categories dichotomized by median. Multivariate logistic regression was used to detect the independent risk factors of severe stroke (NIHSS ≥?7) and receiver operator curve (ROC) was constructed to detect the value of addition of Lp-PLA₂ to the model of other risk factors for predicting severe stroke.

Results

Of the overall patients, the median admission NIHSS scores was 3 and 28.1% had severe manifestation. Admission NIHSS scores were different between patients of Lp-PLA₂ above and under the median (median NIHSS 4 vs. 3, P?<?0.001). Lp-PLA₂ levels was correlated with admission NIHSS (r?=?0.268, P?<?0.001). Logistic regression showed Lp-PLA₂ category (OR 2.37, 95%CI 1.44–3.90, P?<?0.001) and levels per 100 ng/ml (OR 1.69, 95%CI 1.35–2.11, P?<?0.001) were both independently associated with severe stroke. Addition of Lp-PLA₂ category and levels to other independent risk factors both increased the area under curves (from 0.676 to 0.718 with category and 0.734 with levels).

Conclusion

Lp-PLA2 was independently related to admission severity in ischemic stroke patients, implying a potential predictive value of Lp-PLA2 for severe stroke in prevention.

     

GABA<Subscript>A</Subscript> Receptor Downregulation in Brains of Subjects with Autism

Gamma-aminobutyric acid A (GABA(A)) receptors are ligand-gated ion channels responsible for mediation of fast inhibitory action of GABA in the brain. Preliminary reports have demonstrated altered expression of GABA receptors in the brains of subjects with autism suggesting GABA/glutamate system dysregulation. We investigated the expression of four GABA(A) receptor subunits and observed significant reductions in GABRA1, GABRA2, GABRA3, and GABRB3 in parietal cortex (Brodmann's Area 40 (BA40)), while GABRA1 and GABRB3 were significantly altered in cerebellum, and GABRA1 was significantly altered in superior frontal cortex (BA9). The presence of seizure disorder did not have a significant impact on GABA(A) receptor subunit expression in the three brain areas. Our results demonstrate that GABA(A) receptors are reduced in three brain regions that have previously been implicated in the pathogenesis of autism, suggesting widespread GABAergic dysfunction in the brains of subjects with autism.     

<Subscript>L</Subscript>-Theanine Decreases Orofacial Dyskinesia Induced by Reserpine in Rats

Reserpine (RES)-induced orofacial dyskinesia (OD) has been used as an animal model for human tardive dyskinesia (TD) for decades, due to its strong pathophysiological association with striatal oxidative stress and neural cytoarchitecture alteration. _L-Theanine (LT), one of the major amino acid components in green tea, has potent antioxidative, anti-inflammatory, and neuroprotective effects. In this study, we examined the potential protective effects of LT on RES-induced behavioral and neurochemical dysfunction in rats. RES treatment (1 mg/kg s.c., 3 injections 1 day apart) induced significant increases (p?<?0.001) in the frequency of vacuous chewing movements (VCM), tongue protrusion (TP), as well as the duration of facial twitching (FT). LT treatment (100, 300 mg/kg orally for 14 days, starting 10 days before RES injection) was able to prevent most of the RES-induced OD. Moreover, LT treatment reduced the RES-induced lipid peroxidation (LPO) production, increased the antioxidation power and catecholamines in the striatum, and significantly reduced the levels of neuroinflammatory and apoptotic markers. Our results indicated that LT was able to counteract the increased oxidative damage, neurotransmitter deficiency, neuroinflammation, and apoptosis induced by RES, and these results have demonstrated the possible neuroprotective effects of LT against RES-induced OD, including antioxidation, neurochemical deficiency prevention, antineuroinflammation, and antiapoptosis. These findings, therefore, suggest a potential role for LT to have a clinically relevant therapeutic effect in delaying or treating human TD.     

Heart-rate response to alpha<Subscript>2</Subscript>-adrenergic receptor antagonism by antipsychotics

Purpose

To explore the relationship between antipsychotic-associated antagonism of alpha₂-adrenergic receptors and resting heart rate in individuals with schizophrenia.

Methods

Thirty-one inpatients treated with antipsychotics were included in this exploratory analysis. Antipsychotic doses were converted to haloperidol equivalents for alpha₂-adrenergic receptor antagonism. Resting heart rate was measured with the patient in the seated upright posture.

Results

After controlling for confounding variables, the relationship between alpha₂-adrenergic receptor antagonism and resting heart rate demonstrated a positive linear effect (P = 0.002) as well as a nonlinear effect that accounted for an additional 14% of the variability in resting heart rate (P = 0.005).

Conclusion

The observed inverted-U relationship between alpha₂-adrenergic receptor antagonism and resting heart rate can possibly be attributed to an altered response of beta₁-adrenergic receptors to increased norepinephrine release. Further investigations are required to confirm this exploratory finding, taking into account additional variables that include other receptors which either directly or indirectly influence heart rate.

ClinicalTrials.gov Identifier

NCT01392885.