Regulation of DLK-1 kinase activity by calcium-mediated dissociation from an inhibitory isoform.

MAPKKK dual leucine zipper-bearing kinases (DLKs) are regulators of synaptic development and axon regeneration. The mechanisms underlying their activation are not fully understood. Here, we show that C. elegans DLK-1 is activated by a Ca(2+)-dependent switch from inactive heteromeric to active homomeric protein complexes. We identify a DLK-1 isoform, DLK-1S, that shares identical kinase and leucine zipper domains with the previously described long isoform DLK-1L but acts to inhibit DLK-1 function by binding to DLK-1L. The switch between homo- or heteromeric DLK-1 complexes is influenced by Ca(2+) concentration. A conserved hexapeptide in the DLK-1L C terminus is essential for DLK-1 activity and is required for Ca(2+) regulation. The mammalian DLK-1 homolog MAP3K13 contains an identical C-terminal hexapeptide and can functionally complement dlk-1 mutants, suggesting that the DLK activation mechanism is conserved. The DLK activation mechanism is ideally suited for rapid and spatially controlled signal transduction in response to axonal injury and synaptic activity.

Examination of Endogenous Rotund Expression and Function in Developing Drosophila Olfactory System Using CRISPR-Cas9-Mediated Protein Tagging.

The zinc-finger protein Rotund (Rn) plays a critical role in controlling the development of the fly olfactory system. However, little is known about its molecular function in vivo. Here, we added protein tags to the rn locus using CRISPR-Cas9 technology in Drosophila to investigate its subcellular localization and the genes that it regulates . We previously used a reporter construct to show that rn is expressed in a subset of olfactory receptor neuron (ORN) precursors and it is required for the diversification of ORN fates. Here, we show that tagged endogenous Rn protein is functional based on the analysis of ORN phenotypes. Using this method, we also mapped the expression pattern of the endogenous isoform-specific tags in vivo with increased precision. Comparison of the Rn expression pattern from this study with previously published results using GAL4 reporters showed that Rn is mainly present in early steps in antennal disc patterning, but not in pupal stages when ORNs are born. Finally, using chromatin immunoprecipitation, we showed a direct binding of Rotund to a previously identified regulatory element upstream of the bric-a-brac gene locus in the developing antennal disc.

A Peptide Uncoupling BDNF Receptor TrkB from Phospholipase Cγ1 Prevents Epilepsy Induced by Status Epilepticus.

The BDNF receptor tyrosine kinase, TrkB, underlies nervous system function in both health and disease. Excessive activation of TrkB caused by status epilepticus promotes development of temporal lobe epilepsy (TLE), revealing TrkB as a therapeutic target for prevention of TLE. To circumvent undesirable consequences of global inhibition of TrkB signaling, we implemented a novel strategy aimed at selective inhibition of the TrkB-activated signaling pathway responsible for TLE. Our studies of a mouse model reveal that phospholipase Cγ1 (PLCγ1) is the dominant signaling effector by which excessive activation of TrkB promotes epilepsy. We designed a novel peptide (pY816) that uncouples TrkB from PLCγ1. Treatment with pY816 following status epilepticus inhibited TLE and prevented anxiety-like disorder yet preserved neuroprotective effects of endogenous TrkB signaling. We provide proof-of-concept evidence for a novel strategy targeting receptor tyrosine signaling and identify a therapeutic with promise for prevention of TLE caused by status epilepticus in humans.

The origin and evolution of synaptic proteins - choanoflagellates lead the way.

The origin of neurons was a key event in evolution, allowing metazoans to evolve rapid behavioral responses to environmental cues. Reconstructing the origin of synaptic proteins promises to reveal their ancestral functions and might shed light on the evolution of the first neuron-like cells in metazoans. By analyzing the genomes of diverse metazoans and their closest relatives, the evolutionary history of diverse presynaptic and postsynaptic proteins has been reconstructed. These analyses revealed that choanoflagellates, the closest relatives of metazoans, possess diverse synaptic protein homologs. Recent studies have now begun to investigate their ancestral functions. A primordial neurosecretory apparatus in choanoflagellates was identified and it was found that the mechanism, by which presynaptic proteins required for secretion of neurotransmitters interact, is conserved in choanoflagellates and metazoans. Moreover, studies on the postsynaptic protein homolog Homer revealed unexpected localization patterns in choanoflagellates and new binding partners, both which are conserved in metazoans. These findings demonstrate that the study of choanoflagellates can uncover ancient and previously undescribed functions of synaptic proteins.

El uso de la musicoterapia para la mejora de la comunicación de niños con Trastorno del Espectro Autista en Aulas Abiertas Especializadas

Los beneficios que aporta la musicoterapia en alumnos con Trastorno del Espectro Autista, han sido demostrados profusamente por los distintos autores, si bien carecemos de literatura suficiente sobre su utilización en las Aulas Abiertas Especializadas en colegios ordinarios (Aulas TEA). En este sentido, el objetivo del trabajo, ha consistido en analizar qué mejoras aporta la musicoterapia al desarrollo de la comunicación en los alumnos con Trastorno del Espectro Autista dentro de las Aulas Abiertas de los CEIPs de Castilla-La Mancha y la Comunidad Autónoma de Madrid. Para ello, se ha realizado una amplia revisión documental de fuentes de referencia y se ha entrevistado a los docentes responsables de las Aulas Abiertas Especializadas que utilizan actividades de musicoterapia como recurso en el aula. Se concluye el artículo manifestando, en primer lugar, la escasa integración de la musicoterapia en las aulas TEA (menos del 20% de los centros). En aquellas aulas que sí se programa con actividades de musicoterapia, los beneficios que ésta aporta se ven reflejados en un incremento claro de la intención comunicativa en los alumnos. Además, a la hora de planificar las actividades se tiene muy en cuenta conocer las preferencias y la historia musical del niño. No obstante, existen factores que impiden el aprovechamiento total de las posibilidades terapéuticas de la musicoterapia debido, especialmente a: a) una escasa formación del profesorado y b) un espacio inadecuado para poner en práctica una sesión de musicoterapia.

The role of a kinesin, KLP-20, on neural development and epidermal morphogenesis in Caenorhabditis elegans

The heterotrimeric kinesin-II motor in Caenorhabditis elegans consists of KLP-20, KLP-11, and KAP-1 subunits and broadly functions in cellular transport for the development of biological structures including cilia and axons. The results of this paper support the ubiquitous and necessary role kinesin-II motors have in development, particularly the KLP-20 microtubule-associating subunit. Mutations in klp-20 result in a variable abnormal (vab) phenotype characterized by observable epidermal defects, although the role of this gene in development and the mechanism by which the vab phenotype is produced is largely unknown. The vab phenotype is highly penetrant in the first larval stage (L1) of C. elegans, which supports that klp-20 functions in early development. Ciliated amphid sensory neurons can be stained with a fluorescent dye, DiI, to simultaneously test cilia structure and function, as well as the morphology of the amphid sensory organ. Reduced dye uptake in klp-20 mutant L1s suggests that the microtubule-based cilia are under-developed as a result of defective kinesin-II function. Consistent observations of the PLM mechanosensory neuron using the zdIs5 reporter suggest that klp-20 has an essential role in neuron development, as mutations to klp-20 result in under-developed PLM axons. Qualitative observations suggest there may be an interaction between the development of the overlying epidermis and the underlying nervous system, as a more severe vab phenotype is observed simultaneously with reduced dye uptake, and hence amphid sensory cilia under-development. Furthermore, a more severe vab phenotype manifested as large bumps on the posterior epidermis appears to be spatially correlated with PLM defects. The results presented and discussed in this paper suggest that KLP-20 has a necessary role in neurodevelopment and epidermal morphogenesis in C. elegans during embryogenesis.

The Function of Intestinal Afferent Neurons in Regulating Satiety During Health and Obesity

Background and aim: Within the gastrointestinal tract, vagal afferents regulate satiety and food intake via chemical and mechanical mechanisms. Cysteinyl Leukotrienes (CysLTs) are lipid mediators that are believed to regulate food intake and body weight. However, the involvement of vagal afferents in this effect remains to be established. Conversely, Glucagon like peptide-1 (GLP-1) is a satiety and incretin peptide hormone. The effect of obesity on GLP-1 mediated gut-brain signaling has yet to be investigated. Since intestinal vagal afferents’ activity is reduced during obesity, it is intriguing to investigate their responses to GLP-1 in such conditions. Methods: Extracellular recordings were performed on intestinal afferents from normal C57Bl6, low fat fed (LFF), and high fat fed (HFF) mice. To examine the effect on neuronal calcium signaling, calcium-imaging experiments were performed on isolated nodose ganglion neurons. Food intake experiments were conducted using LFF and HFF mice. Oral glucose tolerance tests (OGTT) were carried out. Whole cell patch clamp recordings were performed on nodose ganglion neurons from A) normal C57Bl mice to test the effect of CysLTs on membrane excitability, B) LFF and HFF mice to examine GLP-1 effect on membrane excitability during obesity. c-Fos immunohistochemical techniques were performed to measure the level of neuronal activation in the brainstem of both LFF and HFF mice in response to Ex-4. Results: CysLTs increased intestinal afferent firing rate and mechanosensitivity. In single nodose neuron experiments, CysLTs increased excitability. The GLP-1 agonist Ex-4 significantly decreased food intake in LFF but not HFF mice. However, Ex-4 markedly attenuated the rise in blood glucose in both LFF and HFF mice. The observed increase in nerve firing and mechanosensitivity following the application of GLP-1 and Ex-4 was abolished in HFF mice. Cell membrane excitability was significantly increased by Ex-4 in nodose from LFF but not HFF mice. Ex-4 significantly increased the number of activated neurons in the NTS area of LFF mice but not in their HFF counterparts. Conclusion: The previous observations indicate that the role CysLTs play in regulating satiety is likely to be vagally mediated. Also that satiety, but not incretin, effects of GLP-1 are impaired during obesity.

Computationally efficient sequential learning algorithms for direct link resource-allocating networks

Computionally efficient sequential learning algorithms are developed for direct-link resource-allocating networks (DRANs). These are achieved by decomposing existing recursive training algorithms on a layer by layer and neuron by neuron basis. This allows network weights to be updated in an efficient parallel manner and facilitates the implementation of minimal update extensions that yield a significant reduction in computation load per iteration compared to existing sequential learning methods employed in resource-allocation network (RAN) and minimal RAN (MRAN) approaches. The new algorithms, which also incorporate a pruning strategy to control network growth, are evaluated on three different system identification benchmark problems and shown to outperform existing methods both in terms of training error convergence and computational efficiency. (c) 2005 Elsevier B.V. All rights reserved.

Common input to different regions of biceps brachii long head

The purpose of the experiment was to compare the level of synchronization exhibited by pairs of motor units located within and between functionally distinct regions of the biceps brachii muscle. Pairs of single motor units were recorded from seven subjects using separate electrodes located in the lateral and medial aspects of the long head of biceps brachii. Participants were required to exert a combination of flexion and supination torques so that both motor units discharged at approximately 10 pps for a parts per thousand yen200 s and the level of motor unit synchronization could be quantified. When motor unit recordings were sufficiently stable at the completion of this synchrony task, a series of ramp contractions with multiple combinations of flexion and supination torques were performed to characterize the recruitment thresholds of the motor units. Common input strength (CIS) was significantly greater (P <0.01) for the within-region pairs of motor units (0.28 extra sync. imps/s, n = 26) than for the between-region pairs (0.13 extra sync. imps/s, n = 18), but did not differ significantly for the 12 within-region pairs from the lateral head and 14 from the medial head (0.27 vs. 0.29 extra sync. imps/s; P = 0.83). Recruitment thresholds were measured for 33 motor units, but there was only a weak association between CIS and the respective recruitment patterns for motor unit pairs (n = 9). The present investigation provides evidence of a differential distribution of synaptic input across the biceps brachii motor neuron pool, but this appears to have minimal association with the recruitment patterns for individual motor units.

Increased cerebral output of free radicals during hypoxia: implications for acute mountain sickness?

Bailey DM, Taudorf S, Berg RMG, Lundby C, McEneny J, Young IS, Evans KA, James PE, Shore A, Hullin DA, McCord JM, Pedersen BK, Moller K. Increased cerebral output of free radicals during hypoxia: implications for acute mountain sickness? Am J Physiol Regul Integr Comp Physiol 297: R1283-R1292, 2009. First published September 2, 2009; doi: 10.1152/ajpregu.00366.2009.-This study examined whether hypoxia causes free radical-mediated disruption of the blood-brain barrier (BBB) and impaired cerebral oxidative metabolism and whether this has any bearing on neurological symptoms ascribed to acute mountain sickness (AMS). Ten men provided internal jugular vein and radial artery blood samples during normoxia and 9-h passive exposure to hypoxia (12.9% O-2). Cerebral blood flow was determined by the Kety-Schmidt technique with net exchange calculated by the Fick principle. AMS and headache were determined with clinically validated questionnaires. Electron paramagnetic resonance spectroscopy and ozone-based chemiluminescence were employed for direct detection of spin-trapped free radicals and nitric oxide metabolites. Neuron-specific enolase (NSE), S100 beta, and 3-nitrotyrosine (3-NT) were determined by ELISA. Hypoxia increased the arterio-jugular venous concentration difference (a-v(D)) and net cerebral output of lipid-derived alkoxyl-alkyl free radicals and lipid hydroperoxides (P

Adult neural stem cells expressing IL-10 confer potent immunomodulation and remyelination in experimental autoimmune encephalitis

Adult neural stem cells (aNSCs) derived from the subventricular zone of the brain show therapeutic effects in EAE, an animal model of the chronic inflammatory neurodegenerative disease MS; however, the beneficial effects are modest. One critical weakness of aNSC therapy may be an insufficient antiinflammatory effect. Here, we demonstrate that i.v. or i.c.v. injection of aNSCs engineered to secrete IL-10 (IL-10–aNSCs), a potent immunoregulatory cytokine, induced more profound functional and pathological recovery from ongoing EAE than that with control aNSCs. IL-10–aNSCs exhibited enhanced antiinflammatory effects in the periphery and inflammatory foci in the CNS compared with control aNSCs, more effectively reducing myelin damage, a hallmark of MS. When compared with mice treated with control aNSCs, those treated with IL-10–aNSCs demonstrated differentiation of transplanted cells into greater numbers of oligodendrocytes and neurons but fewer astrocytes, thus enhancing exogenous remyelination and neuron/axonal growth. Finally, IL-10–aNSCs converted a hostile environment to one supportive of neurons/oligodendrocytes, thereby promoting endogenous remyelination. Thus, aNSCs engineered to express IL-10 show enhanced ability to induce immune suppression, remyelination, and neuronal repair and may represent a novel approach that can substantially improve the efficacy of neural stem cell–based therapy in EAE/MS.

BACE1 mRNA Expression in Alzheimer's Disease Postmortem Brain Tissue

ß-site AßPP cleaving enzyme 1 (BACE1) catalyses the rate-limiting step for production of amyloid-ß (Aß) peptides, involved in the pathological cascade underlying Alzheimer's disease (AD). Elevated BACE1 protein levels and activity have been reported in AD postmortem brains. Our study explored whether this was due to elevated BACE1 mRNA expression. RNA was prepared from five brain regions in three study groups: controls, individuals with AD, and another neurodegenerative disease group affected by either Parkinson's disease (PD) or dementia with Lewy bodies (DLB). BACE1 mRNA levels were measured using quantitative realtime PCR (qPCR) and analyzed by qbasePLUS using validated stably-expressed reference genes. Expression of glial and neuronal markers (glial fibrillary acidic protein (GFAP) and neuron-specific enolase (NSE), respectively) were also analyzed to quantify the changing activities of these cell populations in the tissue. BACE1 mRNA levels were significantly elevated in medial temporal and superior parietal gyri, compared to the PD/DLB and/or control groups. Superior frontal gryus BACE1 mRNA levels were significantly increased in the PD/DLB group, compared to AD and control groups. For the AD group, BACE1 mRNA changes were analyzed in the context of the reduced NSE mRNA, and strongly increased GFAP mRNA levels apparent as AD progressed (indicated by Braak stage). This analysis suggested that increased BACE1 mRNA expression in remaining neuronal cells may contribute to the increased BACE1 protein levels and activity found in brain regions affected by AD.

A heterosynaptic learning rule for neural networks

In this article we intoduce a novel stochastic Hebb-like learning rule for neural networks that is neurobiologically motivated. This learning rule combines features of unsupervised (Hebbian) and supervised (reinforcement) learning and is stochastic with respect to the selection of the time points when a synapse is modified. Moreover, the learning rule does not only affect the synapse between pre- and postsynaptic neuron, which is called homosynaptic plasticity, but effects also further remote synapses of the pre-and postsynaptic neuron. This more complex form of synaptic plasticity has recently come under investigations in neurobiology and is called heterosynaptic plasticity. We demonstrate that this learning rule is useful in training neural networks by learning parity functions including the exclusive-or (XOR) mapping in a multilayer feed-forward network. We find, that our stochastic learning rule works well, even in the presence of noise. Importantly, the mean leaxning time increases with the number of patterns to be learned polynomially, indicating efficient learning.

FMRFamide-like peptides in root knot nematodes and their potential role in nematode physiology

FMRFamide-like peptides (FLPs) are a diverse group of neuropeptides that are expressed abundantly in nematodes. They exert potent physiological effects on locomotory, feeding and reproductive musculature and also act as neuromodulators. However, little is known about the specific expression patterns and functions of individual peptides. The current study employed rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR) to characterize flp genes from infective juveniles of the root knot nematodes, Meloidogyne incognita and Meloidogyne minor. The peptides identified from these transcripts are sequelogs of FLPs from the free-living nematode, Caenorhabditis elegans; the genes have therefore been designated as Mi-flp-1, Mi-flp-7, Mi-flp-12, Mm-flp-12 and Mi-flp-14. Mi-flp-1 encodes five FLPs with the common C-terminal moiety, NFLRFamide. Mi-flp-7 encodes two copies of APLDRSALVRFamide and APLDRAAMVRFamide and one copy of APFDRSSMVRFamide. Mi-flp-12 and Mm-flp-12 encode the novel peptide KNNKFEFIRFamide (a longer version of RNKFEFIRFamide found in C. elegans). Mi-flp-14 encodes a single copy of KHEYLRFamide (commonly known as AF2 and regarded as the most abundant nematode FLP), and a single copy of the novel peptide KHEFVRFamide. These FLPs share a high degree of conservation between Meloidogyne species and nematodes from other clades, including those of humans and animals, perhaps suggesting a common neurophysiological role which may be exploited by novel drugs. FLP immunoreactivity was observed for the first time in Meloidogyne, in the circumpharyngeal nerve ring, pharyngeal nerves and ventral nerve cord. Additionally, in situ hybridization revealed Mi-flp-12 expression in an RIR-like neuron and Mi-flp-14 expression in SMB-like neurons, respectively. These localizations imply physiological roles for FLP-12 and FLP-14 peptides, including locomotion and sensory perception.

Rapid formation of robust auditory memories: Insights from noise

Before a natural sound can be recognized, an auditory signature of its source must be learned through experience. Here we used random waveforms to probe the formation of new memories for arbitrary complex sounds. A behavioral measure was designed, based on the detection of repetitions embedded in noises up to 4 s long. Unbeknownst to listeners, some noise samples reoccurred randomly throughout an experimental block. Results showed that repeated exposure induced learning for otherwise totally unpredictable and meaningless sounds. The learning was unsupervised and resilient to interference from other task-relevant noises. When memories were formed, they emerged rapidly, performance became abruptly near-perfect, and multiple noises were remembered for several weeks. The acoustic transformations to which recall was tolerant suggest that the learned features were local in time. We propose that rapid sensory plasticity could explain how the auditory brain creates useful memories from the ever-changing, but sometimes repeating, acoustical world. © 2010 Elsevier Inc.