Gradients of neurotransmitter receptor expression in the macaque cortex.

Dynamics and functions of neural circuits depend on interactions mediated by receptors. Therefore, a comprehensive map of receptor organization across cortical regions is needed. In this study, we used in vitro receptor autoradiography to measure the density of 14 neurotransmitter receptor types in 109 areas of macaque cortex. We integrated the receptor data with anatomical, genetic and functional connectivity data into a common cortical space. We uncovered a principal gradient of receptor expression per neuron. This aligns with the cortical hierarchy from sensory cortex to higher cognitive areas. A second gradient, driven by serotonin 5-HT1A receptors, peaks in the anterior cingulate, default mode and salience networks. We found a similar pattern of 5-HT1A expression in the human brain. Thus, the macaque may be a promising translational model of serotonergic processing and disorders. The receptor gradients may enable rapid, reliable information processing in sensory cortical areas and slow, flexible integration in higher cognitive areas.

Organization of the macaque monkey inferior parietal lobule based on multimodal receptor architectonics.

The macaque monkey inferior parietal lobe (IPL) is a structurally heterogeneous brain region, although the number of areas it contains and the anatomical/functional relationship of identified subdivisions remains controversial. Neurotransmitter receptor distribution patterns not only reveal the position of the cortical borders, but also segregate areas associated to different functional systems. Thus we carried out a multimodal quantitative analysis of the cyto- and receptor architecture of the macaque IPL to determine the number and extent of distinct areas it encompasses. We identified four areas on the IPL convexity arranged in a caudo-rostral sequence, as well as two areas in the parietal operculum, which we projected onto the Yerkes19 surface. We found rostral areas to have relatively smaller receptor fingerprints than the caudal ones, which is in an agreement with the functional gradient along the caudo-rostral axis described in previous studies. The hierarchical analysis segregated IPL areas into two clusters: the caudal one, contains areas involved in multisensory integration and visual-motor functions, and rostral cluster, encompasses areas active during motor planning and action-related functions. The results of the present study provide novel insights into clarifying the homologies between human and macaque IPL areas. The ensuing 3D map of the macaque IPL, and the receptor fingerprints are made publicly available to the neuroscientific community via the Human Brain Project and BALSA repositories for future cyto- and/or receptor architectonically driven analyses of functional imaging studies in non-human primates.

Significance of Autoantibodies in Autoimmune Encephalitis in Relation to Antigen Localization: An Outline of Frequently Reported Autoantibodies with a Non-Systematic Review.

Autoantibodies related to central nervous system (CNS) diseases propel research on paraneoplastic neurological syndrome (PNS). This syndrome develops autoantibodies in combination with certain neurological syndromes and cancers, such as anti-HuD antibodies in encephalomyelitis with small cell lung cancer and anti-Yo antibodies in cerebellar degeneration with gynecological cancer. These autoantibodies have roles in the diagnosis of neurological diseases and early detection of cancers that are usually occult. Most of these autoantibodies have no pathogenic roles in neuronal dysfunction directly. Instead, antigen-specific cytotoxic T lymphocytes are thought to have direct roles in neuronal damage. The recent discoveries of autoantibodies against neuronal synaptic receptors/channels produced in patients with autoimmune encephalomyelitis have highlighted insights into our understanding of the variable neurological symptoms in this disease. It has also improved our understanding of intractable epilepsy, atypical psychosis, and some demyelinating diseases that are ameliorated with immune therapies. The production and motility of these antibodies through the blood-brain barrier into the CNS remains unknown. Most of these recently identified autoantibodies bind to neuronal and glial cell surface synaptic receptors, potentially altering the synaptic signaling process. The clinical features differ among pathologies based on antibody targets. The investigation of these antibodies provides a deeper understanding of the background of neurological symptoms in addition to novel insights into their basic neuroscience.

Surface trafficking of neurotransmitter receptors: From cultured neurons to intact brain preparations.

Over the last decade, developments in single molecule imaging have changed our vision of synaptic physiology. By providing high spatio-temporal resolution maps of the molecular actors of neurotransmissions, these techniques have revealed that pre- and post-synaptic proteins are not randomly distributed but precisely organized at the nanoscale, and that this specific organization is dynamically regulated. At the centre of synaptic transmissions, neurotransmitter receptors have been shown to form nanodomains at synapses and to dynamically move in and out of these confinement areas through lateral diffusion within the membrane plane on millisecond timescales, thereby directly contributing to the regulation of synaptic transmission and plasticity. Since the vast majority of these discoveries originated from observations made on dissociated neurons lacking several features of brain tissue (e.g. three-dimensional organization, tissue density), they were initially considered with caution. However, the recent implementation of single-particle tracking (SPT) approaches in cultured and acute brain preparations confirmed that early findings on the dynamic properties of receptors at the surface of neurons can be extended to more physiological conditions. Taking example of dopamine D1 and NMDA glutamate receptors we here review our current knowledge of the features of neurotransmitter receptor surface diffusion in intact brain tissue. Through detailed comparison with cultured neurons, we also discuss how these biophysical properties are influenced by the complexity of the extracellular environment. This article is part of the special issue entitled 'Mobility and trafficking of neuronal membrane proteins'.

Fractional occupancy of synaptic binding sites and the molecular plasticity of inhibitory synapses.

The postsynaptic density (PSD) at inhibitory synapses is a complex molecular assembly that serves as a platform for the interaction of neurotransmitter receptors, scaffold and adapter proteins, cytoskeletal elements and signalling molecules. The stability of the PSD depends on a multiplicity of interactions linking individual components. At the same time the PSD retains a substantial degree of flexibility. The continuous exchange of synaptic molecules and the preferential addition or removal of certain components induce plastic changes in the synaptic structure. This property necessarily implies that interactors are in dynamic equilibrium and that not all synaptic binding sites are occupied simultaneously. This review discusses the molecular plasticity of inhibitory synapses in terms of the connectivity of their components. Whereas stable protein complexes are marked by stoichiometric relationships between subunits, the majority of synaptic interactions have fractional occupancy, which is here defined as the non-saturation of synaptic binding sites. Fractional occupancy can have several causes: reduced kinetic or thermodynamic stability of the interactions, an imbalance in the concentrations or limited spatio-temporal overlap of interacting proteins, negative cooperativity or mutually exclusive binding. The role of fractional occupancy in the regulation of synaptic structure and function is explored based on recent data about the connectivity of inhibitory receptors and scaffold proteins. I propose that the absolute quantification of interactors and their stoichiometry at identified synapses can provide new mechanistic insights into the dynamic properties of inhibitory PSDs at the molecular level. This article is part of the special issue entitled 'Mobility and trafficking of neuronal membrane proteins'.

Proteomic Studies on the Swim Bladder of the European Eel (Anguilla anguilla).

The swim bladder of a fish is a vital organ that with gas gland cells in the swim bladder wall enables key physiological functions including buoyancy regulation in the face of different hydrostatic pressures. Specific gas gland cells produce and secrete acidic metabolites into the blood in order to reduce the physical solubility of gases and blood gas transport capacity for regulating the volume of the swim bladder. Transcriptomic analyses have provided evidence at the RNA level but no specific studies at the protein level have been carried out so far. Herein, it was the aim of the study to show swim bladder proteins of the yellow stage European eel by label-free LCMS (Q-Exactive Plus) that resulted in the identification of 6223 protein groups. Neurotransmitter receptors and transporters were enriched in the membrane fraction and enzymes for acid production were observed. The list of identified proteins may represent a useful tool for further proteomics experiments on this organ. All MS proteomics data are available at the PRIDE repository with the dataset identifier PXD007850.

Localization-based super-resolution imaging meets high-content screening.

Single-molecule localization microscopy techniques have proven to be essential tools for quantitatively monitoring biological processes at unprecedented spatial resolution. However, these techniques are very low throughput and are not yet compatible with fully automated, multiparametric cellular assays. This shortcoming is primarily due to the huge amount of data generated during imaging and the lack of software for automation and dedicated data mining. We describe an automated quantitative single-molecule-based super-resolution methodology that operates in standard multiwell plates and uses analysis based on high-content screening and data-mining software. The workflow is compatible with fixed- and live-cell imaging and allows extraction of quantitative data like fluorophore photophysics, protein clustering or dynamic behavior of biomolecules. We demonstrate that the method is compatible with high-content screening using 3D dSTORM and DNA-PAINT based super-resolution microscopy as well as single-particle tracking.

Affinity-Guided Oxime Chemistry for Selective Protein Acylation in Live Tissue Systems.

Catalyst-mediated protein modification is a powerful approach for the imaging and engineering of natural proteins. We have previously developed affinity-guided 4-dimethylaminopyridine (AGD) chemistry as an efficient protein modification method using a catalytic acyl transfer reaction. However, because of the high electrophilicity of the thioester acyl donor molecule, AGD chemistry suffers from nonspecific reactions to proteins other than the target protein in crude biological environments, such as cell lysates, live cells, and tissue samples. To overcome this shortcoming, we here report a new acyl donor/organocatalyst system that allows more specific and efficient protein modification. In this method, a highly nucleophilic pyridinium oxime (PyOx) catalyst is conjugated to a ligand specific to the target protein. The ligand-tethered PyOx selectively binds to the target protein and facilitates the acyl transfer reaction of a mild electrophilic N-acyl-N-alkylsulfonamide acyl donor on the protein surface. We demonstrated that the new catalytic system, called AGOX (affinity-guided oxime) chemistry, can modify target proteins, both in test tubes and cell lysates, more selectively and efficiently than AGD chemistry. Low-background fluorescence labeling of the endogenous cell-membrane proteins, carbonic anhydrase XII and the folate receptor, in live cells allowed for the precise quantification of diffusion coefficients in the protein's native environment. Furthermore, the excellent biocompatibility and bioorthogonality of AGOX chemistry were demonstrated by the selective labeling of an endogenous neurotransmitter receptor in mouse brain slices, which are highly complicated tissue samples.

La 'gate control theory' cincuenta años después / The 'gate control theory' fifty years later

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Déficit de GTPCH 1 autosómico recesivo: importancia del análisis de los neurotransmisores en el líquido cefalorraquídeo / Autosomal recessive GTPCH 1 deficiency: the importance of the analysis of neurotransmitters in cerebrospinal fluid

Introducción. El déficit de la enzima trifosfato de guanosina ciclohidrolasa 1 (GTPCH 1) origina una disminución de la síntesis de la tetrahidrobiopterina (BH4), cofactor indispensable en la síntesis de la tirosina, la dopamina y la serotonina. Es una enfermedad poco frecuente que produce un retraso o regresión psicomotora y trastornos del movimiento, y en la que el tratamiento puede mejorar o incluso corregir la clínica. Caso clínico. Niña afecta de déficit de GTPCH con herencia autosómica recesiva, diagnosticada a los 14 meses con estudio del líquido cefalorraquídeo con déficit de pterinas, HVA y 5-HIAA, test de sobrecarga de fenilalanina y estudio genético positivos. La clínica comenzó a los 5 meses con temblor cefálico y de las extremidades superiores, en reposo e intencional, intermitente, que desapareció en un mes. El desarrollo psicomotor era normal, destacaba una hipotonía axial leve en la exploración y las pruebas complementarias realizadas fueron normales. Posteriormente presentó regresión psicomotora con pérdida del sostén cefálico, disminución de los movimientos activos, dificultad para la manipulación bimanual, hipomimia e hipotonía global grave, lo que motivó el estudio de una encefalopatía progresiva. Tras el diagnóstico de déficit de GTPCH, inició tratamiento sustitutivo con levodopa/carbidopa, OH triptófano y BH4, con muy buena evolución tanto motora como cognitiva. Actualmente, la paciente tiene 5 años, presenta un desarrollo psicomotor adecuado a su edad, cursa tercer curso de educación infantil y ha alcanzado el nivel de su clase. Conclusión. Hay que destacar en este caso la mejoría tan satisfactoria, tanto motora como cognitiva, tras iniciar el tratamiento sustitutivo, ya que el nivel cognitivo suele quedar afectado en muchos casos (AU)

Introduction. A deficiency of the enzyme guanosine triphosphate cyclohydrolase I (GTPCH 1) causes a reduction in the synthesis of tetrahydrobiopterin (BH4), a cofactor that is essential in the synthesis of tyrosine, dopamine and serotonin. It is an infrequent disease that produces psychomotor delay or regression and movement disorders, although treatment can improve or even correct the clinical signs and symptoms. Case report. We report the case of a girl with autosomal recessive GTPCH deficiency, who was diagnosed at 14 months by means of an analysis of the cerebrospinal fluid with pterin, HVA and 5-HIAA deficiency, and positive phenylalanine overload test and genetic study. The clinical features began at the age of 5 months with intermittent upper limb and brain tremors, both at rest and intentional, that disappeared after a month. Psychomotor development was normal, mild axial hypotonia being found in the examination while the complementary tests that were performed were normal. The patient later presented psychomotor regression with loss of head control, diminished active movements, difficulty in bimanual manipulation, hypomimia and severe global hypotonia, which was the reason for the study of a progressive encephalopathy. Following the diagnosis of GTPCH deficiency, replacement therapy was established with levodopa/carbidopa, OH tryptophan and BH4, with excellent progress made in motor and cognitive functioning. Today, the patient is 5 years old, has an adequate psychomotor development for her age, is in the third year of preschool education and has caught up with the level of the rest of her classmates. Conclusion. In this case attention must be drawn to the extremely satisfactory motor and cognitive improvement of the patient after starting replacement therapy, as in many cases the cognitive level is usually affected on a permanent basis (AU)

Multimodal analysis of cortical chemoarchitecture and macroscale fMRI resting-state functional connectivity.

The cerebral cortex is well known to display a large variation in excitatory and inhibitory chemoarchitecture, but the effect of this variation on global scale functional neural communication and synchronization patterns remains less well understood. Here, we provide evidence of the chemoarchitecture of cortical regions to be associated with large-scale region-to-region resting-state functional connectivity. We assessed the excitatory versus inhibitory chemoarchitecture of cortical areas as an ExIn ratio between receptor density mappings of excitatory (AMPA, M1 ) and inhibitory (GABAA , M2 ) receptors, computed on the basis of data collated from pioneering studies of autoradiography mappings as present in literature of the human (2 datasets) and macaque (1 dataset) cortex. Cortical variation in ExIn ratio significantly correlated with total level of functional connectivity as derived from resting-state functional connectivity recordings of cortical areas across all three datasets (human I: P = 0.0004; human II: P = 0.0008; macaque: P = 0.0007), suggesting cortical areas with an overall more excitatory character to show higher levels of intrinsic functional connectivity during resting-state. Our findings are indicative of the microscale chemoarchitecture of cortical regions to be related to resting-state fMRI connectivity patterns at the global system's level of connectome organization. Hum Brain Mapp 37:3103-3113, 2016. © 2016 Wiley Periodicals, Inc.

Neurotransmitter receptor complexes: methods for bioanalysis, their potentials and limitations.

Neurotransmitter receptors are key elements for brain function, but work so far has been focusing on the individual receptor subunits. It is, however, the receptor complexes that execute work rather than the subunits; of course, the multitude of possible combinations of the many receptors forming homomeric or heteromeric complexes is hampering studies. Moreover, not only receptors are observed in the complexes but also their corresponding protein kinases, phosphatases, and anchoring proteins, to name a few. Studying receptor complexes is still an analytical challenge. Thus far, no methods exist to unequivocally characterize or even quantify these assemblies. Major problems and limitations for the analysis exist, such as solubility, as the use of detergents is critical and may dissociate the receptor complexes as well as their separation in the native state. Gel-based techniques are able to separate and semiquantitatively quantify receptor complexes by subsequent immunochemical methods but do not allow the characterization of complex components. Immunoprecipitation methods are highly dependent on antibody availability and specificity, and the result of coimmunoprecipitation does not verify the direct physical interaction of proteins in the immunoprecipitate. Antibody shift assays are suitable to identify individual known proteins within a complex as are immunogold electron microscopic techniques and energy transfer technologies. Most techniques are simply showing the proximity of proteins rather than their physical interaction. Although fluorescence correlation spectroscopy is a promising technique, the use for quantification or comparing biological samples is limited. A lot of work remains to be done to provide tools for the characterization and quantification of receptor complexes in the brain.

Estrategia multimarcador para estratificar el pronóstico en insuficiencia cardiaca. Valor de los marcadores neurohumorales: neprilisina frente a NT-proBNP / Multimarker strategy for heart failure prognostication. Value of neurohormonal biomarkers: neprilysin vs NT-proBNP

Introducción y objetivos: La neprilisina degrada numerosos péptidos vasoactivos. La forma soluble de neprilisina, que se ha identificado recientemente en la insuficiencia cardiaca, se asocia con eventos cardiovasculares. Se compararon de manera directa la neprilisina soluble y la fracción aminoterminal del propéptido natriurético cerebral como estratificadores de riesgo, dentro de una estrategia multimarcadores, en una cohorte de pacientes con insuficiencia cardiaca de la práctica clínica real. Métodos: Se determinaron las concentraciones de neprilisina soluble, la fracción aminoterminal del propéptido natriurético cerebral, ST2 y troponina T de alta sensibilidad en 797 pacientes ambulatorios consecutivos con insuficiencia cardiaca seguidos durante 4,7 años. Se llevaron a cabo análisis multivariables exhaustivos y se realizaron comparaciones directas de neprilisina soluble frente a la fracción aminoterminal del propéptido natriurético cerebral mediante estadísticas de rendimiento. El objetivo final principal fue el compuesto por muerte cardiovascular u hospitalización por insuficiencia cardiaca. Un objetivo secundario exploró la muerte cardiovascular sola. Resultados: Las medianas de concentración de neprilisina soluble y la fracción aminoterminal del propéptido natriurético cerebral fueron de 0,64 ng/ml y 1.187 ng/l respectivamente. Ambos biomarcadores presentaron una correlación significativa con la edad (p < 0,001) y las cifras de ST2 (p < 0,001), pero solo la fracción aminoterminal del propéptido natriurético cerebral mostró una correlación significativa con el filtrado glomerular estimado (p < 0,001), el índice de masa corporal (p < 0,001), la fracción de eyección del ventrículo izquierdo (p = 0,02) y la troponina T de alta sensibilidad (p < 0,001). En los análisis de regresión de Cox multivariables, la neprilisina soluble continuó mostrando una asociación independiente con el objetivo compuesto (hazard ratio = 1,14; intervalo de confianza del 95%, 1,02-1,27; p = 0,03) y la muerte cardiovascular (hazard ratio = 1,15; intervalo de confianza del 95%, 1,01-1,31; p = 0,04), pero no así la fracción aminoterminal del propéptido natriurético cerebral. La comparación directa de la neprilisina soluble con la fracción aminoterminal del propéptido natriurético cerebral puso de manifiesto buena calibración y discriminación y reclasificación similares con ambos biomarcadores neurohormonales, pero solo la neprilisina soluble mejoró la bondad de ajuste global. Conclusiones: La neprilisina soluble mantuvo el valor pronóstico independiente al incluirlo en una estrategia multimarcadores, mientras que la fracción aminoterminal del propéptido natriurético cerebral perdió la significación en la estratificación del riesgo en los pacientes ambulatorios con insuficiencia cardiaca. Ambos biomarcadores obtuvieron medidas de rendimiento similares en los análisis de comparación directa (AU)

Introduction and objectives: Neprilysin breaks down numerous vasoactive peptides. The soluble form of neprilysin, which was recently identified in heart failure, is associated with cardiovascular outcomes. Within a multibiomarker strategy, we directly compared soluble neprilysin and N-terminal pro-B-type natriuretic peptide as risk stratifiers in a real-life cohort of heart failure patients. Methods: Soluble neprilysin, N-terminal pro-B-type natriuretic peptide, ST2, and high-sensitivity troponin T levels were measured in 797 consecutive ambulatory heart failure patients followed up for 4.7 years. Comprehensive multivariable analyses and soluble neprilysin vs N-terminal pro-B-type natriuretic peptide head-to-head assessments of performance were performed. A primary composite endpoint included cardiovascular death or heart failure hospitalization. A secondary endpoint explored cardiovascular death alone. Results: Median soluble neprilysin and N-terminal pro-B-type natriuretic peptide concentrations were 0.64 ng/mL and 1187 ng/L, respectively. Both biomarkers significantly correlated with age (P < .001) and ST2 (P < .001), but only N-terminal pro-B-type natriuretic peptide significantly correlated with estimated glomerular filtration rate (P < .001), body mass index (P < .001), left ventricular ejection fraction (P = .02) and high-sensitivity troponin T (P < .001). In multivariable Cox regression analyses, soluble neprilysin remained independently associated with the composite endpoint (hazard ratio = 1.14; 95% confidence interval, 1.02-1.27; P = .03) and cardiovascular death (hazard ratio = 1.15; 95% confidence interval, 1.01-1.31; P = .04), but N-terminal pro-B-type natriuretic peptide did not. The head-to-head soluble neprilysin vs N-terminal pro-B-type natriuretic peptide comparison showed good calibration and similar discrimination and reclassification for both neurohormonal biomarkers, but only soluble neprilysin improved overall goodness-of-fit. Conclusions: When added to a multimarker strategy, soluble neprilysin remained an independent prognosticator, while N-terminal pro-B-type natriuretic peptide lost significance as a risk stratifier in ambulatory patients with heart failure. Both biomarkers performed similarly in head-to-head analyses (AU)

Frontal cortex and hippocampus neurotransmitter receptor complex level parallels spatial memory performance in the radial arm maze.

Several neurotransmitter receptors have been proposed to be involved in memory formation. However, information on receptor complexes (RCs) in the radial arm maze (RAM) is missing. It was therefore the aim of this study to determine major neurotransmitter RCs levels that are modulated by RAM training because receptors are known to work in homo-or heteromeric assemblies. Immediate early gene Arc expression was determined by immunohistochemistry to show if prefrontal cortices (PFC) and hippocampi were activated following RAM training as these regions are known to be mainly implicated in spatial memory. Twelve rats per group, trained and untrained in the twelve arm RAM were used, frontal cortices and hippocampi were taken, RCs in membrane protein were quantified by blue-native PAGE immunoblotting. RCs components were characterised by co-immunoprecipitation followed by mass spectrometrical analysis and by the use of the proximity ligation assay. Arc expression was significantly higher in PFC of trained as compared to untrained rats whereas it was comparable in hippocampi. Frontal cortical levels of RCs containing AMPA receptors GluA1, GluA2, NMDA receptors GluN1 and GluN2A, dopamine receptor D1, acetylcholine nicotinic receptor alpha 7 (nAChR-α7) and hippocampal levels of RCs containing D1, GluN1, GluN2B and nAChR-α7 were increased in the trained group; phosphorylated dopamine transporter levels were decreased in the trained group. D1 and GluN1 receptors were shown to be in the same complex. Taken together, distinct RCs were paralleling performance in the RAM which is relevant for interpretation of previous and design of future work on RCs in memory studies.

Cingulate area 32 homologies in mouse, rat, macaque and human: cytoarchitecture and receptor architecture.

Homologizing between human and nonhuman area 32 has been impaired since Brodmann said he could not homologize with certainty human area 32 to a specific cortical domain in other species. Human area 32 has four divisions, however, and two can be structurally homologized to nonhuman species with cytoarchitecture and receptor architecture: pregenual (p32) and subgenual (s32) in human and macaque monkey and areas d32 and v32 in rat and mouse. Cytoarchitecture showed that areas d32/p32 have a dysgranular layer IV in all species and that areas v32/s32 have large and dense neurons in layer V, whereas a layer IV is not present in area v32. Areas v32/s32 have the largest neurons in layer Va. Features unique to humans include large layer IIIc pyramids in both divisions, sparse layer Vb in area p32, and elongated neurons in layer VI, with area s32 having the largest layer Va neurons. Receptor fingerprints of both subdivisions of area 32 differed between species in size and shape, although AMPA/GABAA and NMDA/GABAA ratios were comparable among humans, monkeys, and rats and were significantly lower than in mice. Layers I-III of primate and rodent area 32 subdivisions share more similarities in their receptor densities than layers IV-VI. Monkey and human subdivisions of area 32 are more similar to each other than to rat and mouse subdivisions. In combination with intracingulate connections, the location, cytoarchitecture, and ligand binding studies demonstrate critical homologies among the four species.

Organization of the human inferior parietal lobule based on receptor architectonics.

Human inferior parietal lobule (IPL) plays a key role in various cognitive functions. Its functional diversity, including attention, language, and action processing, is reflected by its structural segregation into 7 cytoarchitectonically distinct areas, each with characteristic connectivity patterns. We hypothesized that commonalities of the cytoarchitectonic, connectional, and functional diversity of the IPL should be reflected by a correlated transmitter receptor-based organization. Since the function of a cortical area requires a well-tuned receptor balance, the densities of 15 different receptors were measured in each IPL area. A hierarchical cluster analysis of the receptor balance revealed a tripartite segregation of the IPL into a rostral, middle, and caudal group. Comparison with other cortical areas showed strong similarities with Broca's region for all 3 groups, with the superior parietal cortex for the middle, and with extrastriate visual areas for the caudal group. Notably, caudal-most area PGp has a receptor fingerprint very similar to that of ventral extrastriate visual cortex. We therefore propose a new organizational model of the human IPL, consisting of 3 clusters, which corresponds to its known cytoarchitectonic, connectional, and functional diversity at the molecular level. This might reflect a general organizational principle of human IPL, beyond specific functional domains.

Metallic gold slows disease progression, reduces cell death and induces astrogliosis while simultaneously increasing stem cell responses in an EAE rat model of multiple sclerosis.

Multiple sclerosis (MS) is the most common neurodegenerative disease in the Western world affecting younger, otherwise healthy individuals. Today no curative treatment exists. Patients suffer from recurring attacks caused by demyelination and underlying neuroinflammation, ultimately leading to loss of neurons. Recent research shows that bio-liberation of gold ions from metallic gold implants can ameliorate inflammation, reduce apoptosis and promote proliferation of neuronal stem cells (NSCs) in a mouse model of focal brain injury. Based on these findings, the present study investigates whether metallic gold implants affect the clinical signs of disease progression and the pathological findings in experimental autoimmune encephalomyelitis (EAE), a rodent model of MS. Gold particles 20-45 µm suspended in hyaluronic acid were bilaterally injected into the lateral ventricles (LV) of young Lewis rats prior to EAE induction. Comparing gold-treated animals to untreated and vehicle-treated ones, a statistically significant slowing of disease progression in terms of reduced weight loss was seen. Despite massive inflammatory infiltration, terminal deoxynucleotidyl transferase dUTP nick end labeling staining revealed reduced apoptotic cell death in disease foci in the brain stem of gold-treated animals, alongside an up-regulation of glial fibrillary acidic protein-positive reactive astrocytes near the LV and in the brain stem. Cell counting of frizzled-9 and nestin-stained cells showed statistically significant up-regulation of NSCs migrating from the subventricular zone. Additionally, the neuroprotective proteins Metallothionein-1 and -2 were up-regulated in the corpus callosum. In conclusion, this study is the first to show that the presence of small gold implants affect disease progression in a rat model of MS, increasing the neurogenic response and reducing the loss of cells in disease foci. Gold implants might thus improve clinical outcome for MS patients and further research into the long-term effects of such localized gold treatment is warranted.

Proliferative enteropathy (PE)-induced changes in the calbindin-immunoreactive (CB-IR) neurons of inferior mesenteric ganglion supplying the descending colon in the pig.

A subpopulation of the pig inferior mesenteric ganglia (IMG) neurons projecting to the colon exhibit calbindin-like immunoreactivity. It is not known if there are any changes in the chemical coding patterns of these neurons during porcine proliferative enteropathy (PE). To answer this question, juvenile Large White Polish pigs with clinically diagnosed Lawsonia intracellularis infection (PE; n = 3) and a group of uninfected controls (C; n = 3) were compared. The retrograde tracer fast blue (FB) was injected into the descending colons of all animals and then tissue comprising IMGs from both groups was processed for double-labeling immunofluorescence with calbindin-D28k (CB) in combination with either tyrosine hydroxylase (TH), neuropeptide Y (NPY), somatostatin (SOM), vasoactive intestinal polypeptide (VIP), nitric oxide synthase, Leu-enkephalin, substance P, vesicular acetylcholine transporter, galanin, or pituitary adenylate cyclase-activating polypeptide. Immunohistochemistry revealed changes in the chemical coding pattern of calbindin-immunoreactive neurons in the inferior mesenteric ganglia of the pig. In control animals, FB/CB-positive neurons were immunoreactive to TH, NPY, SOM, and VIP. In the experimental group, TH-expressing neurons were unaffected, NPY-expressing neurons were increased, whereas the number of neurons immunoreactive to SOM or VIP was reduced. Changes in chemical coding of CB neurons during PE may play an important role in adaptation of these IMG cells under pathological conditions.

The regulatory mechanism of neuromedin S on luteinizing hormone in pigs.

Neuromedin S (NMS) has been implicated in the regulation of luteinizing hormone (LH) secretion. However, the regulatory mechanism of NMS on LH in pigs remains unexplored. In the present study, we confirmed the hypothesis that the effect of NMS on LH could be mediated via hypothalamic melanocyte-stimulating hormones (MSH) neurons of ovariectomized pigs. In an immunohistological experiment, NMS receptor NMU2R-positive neurons were found in the paraventricular nucleus of hypothalamus, widely distributed in the anterior pituitary, and sparsely observed in the posterior pituitary. We also found that serum LH level was declined at between 12 and 60 min with the lowest level at 24 min after NMS injection. The decreased LH secretion induced by NMS could be completely abolished by pretreatment with melanocortin receptor-4 antagonist SHU9119, while a signal injection of 1.0 nM SHU9119 per se did not affect the serum LH level. Real time quantitative RT-PCR results showed that the expression of GnRH and LH mRNAs were down-regulated by NMS treatment, but their reduction was restored to normal level by SHU9119 treatments. The expression of NMU2R and PR mRNAs were up-regulated by NMS treatment, but their effects were blocked by SHU9119 treatments. The expression of the estrogen receptor mRNA in the pig hypothalamus and pituitary was unchanged under the NMS and SHU9119+NMS treatments. In summary, all results suggest that the inhibitory effect of NMS on LH is at least in part through its receptor NMU2R and mediated via MSH neurons in hypothalamus-pituitary axis of ovariectomized pigs.

The stress hormone corticosterone increases synaptic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors via serum- and glucocorticoid-inducible kinase (SGK) regulation of the GDI-Rab4 complex.

Corticosterone, the major stress hormone, plays an important role in regulating neuronal functions of the limbic system, although the cellular targets and molecular mechanisms of corticosteroid signaling are largely unknown. Here we show that a short treatment of corticosterone significantly increases alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated synaptic transmission and AMPAR membrane trafficking in pyramidal neurons of prefrontal cortex, a key region involved in cognition and emotion. This enhancing effect of corticosterone is through a mechanism dependent on Rab4, the small GTPase-controlling receptor recycling between early endosome and plasma membrane. Guanosine nucleotide dissociation inhibitor (GDI), which regulates the cycle of Rab proteins between membrane and cytosol, forms an increased complex with Rab4 after corticosterone treatment. Corticosterone also triggers an increased GDI phosphorylation at Ser-213 by the serum- and glucocorticoid-inducible kinase (SGK). Moreover, AMPAR synaptic currents and surface expression and their regulation by corticosterone are altered by mutating Ser-213 on GDI. These results suggest that corticosterone, via SGK phosphorylation of GDI at Ser-213, increases the formation of GDI-Rab4 complex, facilitating the functional cycle of Rab4 and Rab4-mediated recycling of AMPARs to the synaptic membrane. It provides a potential mechanism underlying the role of corticosteroid stress hormone in up-regulating excitatory synaptic efficacy in cortical neurons.