This is an RSS newsfeed from BioMed Central It is intended to be used with an RSS reader. For more information about RSS newsfeeds from BioMed Central, visit http://www.biomedcentral.com/info/about/rss/ http://www.biomedcentral.com/bmcneurosci/mostviewed/ Most viewed articles in last 30 days from BMC Neuroscience (ISSN 1471-2202) published by BioMed Central Background: Specific pieces of music can elicit strong emotions in listeners and, possibly in connection with these emotions, can be remembered even years later. However, episodic memory for emotional music compared with less emotional music has not yet been examined. We investigated whether emotional music is remembered better than less emotional music. Also, we examined the influence of musical structure on memory performance. Results: Recognition of 40 musical excerpts was investigated as a function of arousal, valence, and emotional intensity ratings of the music. In the first session the participants judged valence and arousal of the musical pieces. One week later, participants listened to the 40 old and 40 new musical excerpts randomly interspersed and were asked to make an old/new decision as well as to indicate arousal and valence of the pieces. Musical pieces that were rated as very positive were recognized significantly better. Conclusion: Musical excerpts rated as very positive are remembered better. Valence seems to be an important modulator of episodic long-term memory for music. Evidently, strong emotions related to the musical experience facilitate memory formation and retrieval. http://www.biomedcentral.com/1471-2202/9/48 Susann Eschrich, Thomas F Münte and Eckart O Altenmüller BMC Neuroscience 2008, 9:48 Number of accesses: 559 2008-05-28 doi:10.1186/1471-2202-9-48 BMC Neuroscience 1471-2202 9 48 2008-05-28 Background: Mutations, toxic insults and radiation exposure are known to slow or arrest the migration of cortical neurons, in most cases by unknown mechanisms. The movement of migrating neurons is saltatory, reflecting the intermittent movement of the nucleus (nucleokinesis) within the confines of the plasma membrane. Each nucleokinetic movement is analogous to a step. Thus, average migration speed could be reduced by lowering step frequency and/or step distance. Results: To assess the kinetic features of cortical neuron migration we developed a cell culture system that supports fiber-guided migration. In this system, the majority of fiber-apposed cells were neurons, expressed age-appropriate cortical-layer specific markers and migrated during a 30 min imaging period. Comparison of the slowest and fastest quartiles of cells revealed a 5-fold difference in average speed. The major determinant of average speed in slower cells (6–26 μm/hr) was step frequency, while step distance was the critical determinant of average speed in faster cells (>26 μm/hr). Surprisingly, step distance was largely determined by the average duration of the step, rather than the speed of nucleokinesis during the step, which differed by only 1.3-fold between the slowest and fastest quartiles. Conclusion: Saltatory event frequency and duration, not nucleokinetic speed, are the major determinants of average migration speed in healthy neurons. Alteration of either saltatory event frequency or duration should be considered along with nucleokinetic abnormalities as possible contributors to pathological conditions. http://www.biomedcentral.com/1471-2202/9/50 Anna J Nichols, Laurel H Carney and Eric C Olson BMC Neuroscience 2008, 9:50 Number of accesses: 527 2008-06-05 doi:10.1186/1471-2202-9-50 BMC Neuroscience 1471-2202 9 50 2008-06-05 Background: Consciousness poses two main problems. The first is understanding the conditions that determine to what extent a system has conscious experience. For instance, why is our consciousness generated by certain parts of our brain, such as the thalamocortical system, and not by other parts, such as the cerebellum? And why are we conscious during wakefulness and much less so during dreamless sleep? The second problem is understanding the conditions that determine what kind of consciousness a system has. For example, why do specific parts of the brain contribute specific qualities to our conscious experience, such as vision and audition?Presentation of the hypothesisThis paper presents a theory about what consciousness is and how it can be measured. According to the theory, consciousness corresponds to the capacity of a system to integrate information. This claim is motivated by two key phenomenological properties of consciousness: differentiation – the availability of a very large number of conscious experiences; and integration – the unity of each such experience. The theory states that the quantity of consciousness available to a system can be measured as the Φ value of a complex of elements. Φ is the amount of causally effective information that can be integrated across the informational weakest link of a subset of elements. A complex is a subset of elements with Φ>0 that is not part of a subset of higher Φ. The theory also claims that the quality of consciousness is determined by the informational relationships among the elements of a complex, which are specified by the values of effective information among them. Finally, each particular conscious experience is specified by the value, at any given time, of the variables mediating informational interactions among the elements of a complex.Testing the hypothesisThe information integration theory accounts, in a principled manner, for several neurobiological observations concerning consciousness. As shown here, these include the association of consciousness with certain neural systems rather than with others; the fact that neural processes underlying consciousness can influence or be influenced by neural processes that remain unconscious; the reduction of consciousness during dreamless sleep and generalized seizures; and the time requirements on neural interactions that support consciousness.Implications of the hypothesisThe theory entails that consciousness is a fundamental quantity, that it is graded, that it is present in infants and animals, and that it should be possible to build conscious artifacts. http://www.biomedcentral.com/1471-2202/5/42 Giulio Tononi BMC Neuroscience 2004, 5:42 Number of accesses: 454 2004-11-02 doi:10.1186/1471-2202-5-42 BMC Neuroscience 1471-2202 5 42 2004-11-02 Background: Neurogenesis continues to occur throughout life but dramatically decreases with increasing age. This decrease is mostly related to a decline in proliferative activity as a result of an impoverishment of the microenvironment of the aged brain, including a reduction in trophic factors and increased inflammation. Results: We determined that human umbilical cord blood mononuclear cells (UCBMC) given peripherally, by an intravenous injection, could rejuvenate the proliferative activity of the aged neural stem/progenitor cells. This increase in proliferation lasted for at least 15 days after the delivery of the UCBMC. Along with the increase in proliferation following UCBMC treatment, an increase in neurogenesis was also found in the aged animals. The increase in neurogenesis as a result of UCBMC treatment seemed to be due to a decrease in inflammation, as a decrease in the number of activated microglia was found and this decrease correlated with the increase in neurogenesis. Conclusion: The results demonstrate that a single intravenous injection of UCBMC in aged rats can significantly improve the microenvironment of the aged hippocampus and rejuvenate the aged neural stem/progenitor cells. Our results raise the possibility of a peripherally administered cell therapy as an effective approach to improve the microenvironment of the aged brain. http://www.biomedcentral.com/1471-2202/9/22 Adam D Bachstetter, Mibel M Pabon, Michael J Cole, Charles E Hudson, Paul R Sanberg, Alison E Willing, Paula C Bickford and Carmelina Gemma BMC Neuroscience 2008, 9:22 Number of accesses: 422 2008-02-14 doi:10.1186/1471-2202-9-22 BMC Neuroscience 1471-2202 9 22 2008-02-14 Background: Preparation of the direction of a forthcoming movement has a particularly strong influence on both reaction times and neuronal activity in the primate motor cortex. Here, we aimed to find direct neurophysiological evidence for the preparation of movement direction in humans. We used single pulse transcranial magnetic stimulation (TMS) to evoke isolated thumb-movements, of which the direction can be modulated experimentally, for example by training or by motor tasks. Sixteen healthy subjects performed brisk concentric voluntary thumb movements during a reaction time task in which the required movement direction was precued. We assessed whether preparation for the thumb movement lead to changes in the direction of TMS-evoked movements and to changes in amplitudes of motor-evoked potentials (MEPs) from the hand muscles. Results: When the required movement direction was precued early in the preparatory interval, reaction times were 50 ms faster than when precued at the end of the preparatory interval. Over time, the direction of the TMS evoked thumb movements became increasingly variable, but it did not turn towards the precued direction. MEPs from the thumb muscle (agonist) were differentially modulated by the direction of the precue, but only in the late phase of the preparatory interval and thereafter. MEPs from the index finger muscle did not depend on the precued direction and progressively decreased during the preparatory interval. Conclusion: Our data show that the human corticospinal movement representation undergoes progressive changes during motor preparation. These changes are accompanied by inhibitory changes in corticospinal excitability, which are muscle specific and depend on the prepared movement direction. This inhibition might indicate a corticospinal braking mechanism that counteracts any preparatory motor activation. http://www.biomedcentral.com/1471-2202/9/51 Gijs van Elswijk, Willemijn D Schot, Dick F Stegeman and Sebastiaan Overeem BMC Neuroscience 2008, 9:51 Number of accesses: 352 2008-06-17 doi:10.1186/1471-2202-9-51 BMC Neuroscience 1471-2202 9 51 2008-06-17 Background: Huntington's disease (HD) is a neurodegenerative disorder predominantly affecting the cerebral cortex and striatum. Transgenic mice (R6/1 line), expressing a CAG repeat encoding an expanded polyglutamine tract in the N-terminus of the huntingtin protein, closely model HD. We have previously shown that environmental enrichment of these HD mice delays the onset of motor deficits. Furthermore, wheel running initiated in adulthood ameliorates the rear-paw clasping motor sign, but not an accelerating rotarod deficit. Results: We have now examined the effects of enhanced physical activity via wheel running, commenced at a juvenile age (4 weeks), with respect to the onset of various behavioral deficits and their neuropathological correlates in R6/1 HD mice. HD mice housed post-weaning with running wheels only, to enhance voluntary physical exercise, have delayed onset of a motor co-ordination deficit on the static horizontal rod, as well as rear-paw clasping, although the accelerating rotarod deficit remains unaffected. Both wheel running and environmental enrichment rescued HD-induced abnormal habituation of locomotor activity and exploratory behavior in the open field. We have found that neither environment enrichment nor wheel running ameliorates the shrinkage of the striatum and anterior cingulate cortex (ACC) in HD mice, nor the overall decrease in brain weight, measured at 9 months of age. At this age, the density of ubiquitinated protein aggregates in the striatum and ACC is also not significantly ameliorated by environmental enrichment or wheel running. Conclusion: These results indicate that enhanced voluntary physical activity, commenced at an early presymptomatic stage, contributes to the positive effects of environmental enrichment. However, sensory and cognitive stimulation, as well as motor stimulation not associated with running, may constitute major components of the therapeutic benefits associated with enrichment. Comparison of different environmental manipulations, performed in specific time windows, can identify critical periods for the induction of neuroprotective 'brain reserve' in animal models of HD and related neurodegenerative diseases. http://www.biomedcentral.com/1471-2202/9/34 Anton van Dellen, Patricia M Cordery, Tara L Spires, Colin Blakemore and Anthony J Hannan BMC Neuroscience 2008, 9:34 Number of accesses: 298 2008-04-01 doi:10.1186/1471-2202-9-34 BMC Neuroscience 1471-2202 9 34 2008-04-01 Background: Methamphetamine (MA) use is a worldwide problem. Abusers can have cognitive deficits, monoamine reductions, and altered magnetic resonance spectroscopy findings. Animal models have been used to investigate some of these effects, however many of these experiments have not examined the impact of MA on the stress response. For example, numerous studies have demonstrated (+)-MA-induced neurotoxicity and monoamine reductions, however the effects of MA on other markers that may play a role in neurotoxicity or cell energetics such as glucose, corticosterone, and/or creatine have received less attention. In this experiment, the effects of a neurotoxic regimen of (+)-MA (4 doses at 2 h intervals) on brain monoamines, neostriatal GFAP, plasma corticosterone, creatinine, and glucose, and brain and muscle creatine were evaluated 1, 7, 24, and 72 h after the first dose. In order to compare MA's effects with stress, animals were subjected to a forced swim test in a temporal pattern similar to MA administration [i.e., (30 min/session) 4 times at 2 h intervals]. Results: MA increased corticosterone from 1–72 h with a peak 1 h after the first treatment, whereas glucose was only increased 1 h post-treatment. Neostriatal and hippocampal monoamines were decreased at 7, 24, and 72 h, with a concurrent increase in GFAP at 72 h. There was no effect of MA on regional brain creatine, however plasma creatinine was increased during the first 24 h and decreased by 72 h. As with MA treatment, forced swim increased corticosterone more than MA initially. Unlike MA, forced swim reduced creatine in the cerebellum with no change in other brain regions while plasma creatinine was decreased at 1 and 7 h. Glucose in plasma was decreased at 7 h. Conclusion: Both MA and forced swim increase demand on energy substrates but in different ways, and MA has persistent effects on corticosterone that are not attributable to stress alone. http://www.biomedcentral.com/1471-2202/9/49 Nicole R Herring, Tori L Schaefer, Peter H Tang, Matthew R Skelton, James P Lucot, Gary A Gudelsky, Charles V Vorhees and Michael T Williams BMC Neuroscience 2008, 9:49 Number of accesses: 257 2008-05-30 doi:10.1186/1471-2202-9-49 BMC Neuroscience 1471-2202 9 49 2008-05-30 Background: There is fMRI evidence that women are neurally predisposed to process infant laughter and crying. Other findings show that women might be more empathic and sensitive than men to emotional facial expressions. However, no gender difference in the brain responses to persons and unanimated scenes has hitherto been demonstrated. Results: Twenty-four men and women viewed 220 images portraying persons or landscapes and ERPs were recorded from 128 sites. In women, but not in men, the N2 component (210-270) was much larger to persons than to scenes. swLORETA showed significant bilateral activation of FG (BA19/37) in both genders when viewing persons as opposed to scenes. Only women showed a source of activity in the STG and in the right MOG (extra-striate body area, EBA), and only men in the left parahippocampal area (PPA). Conclusions: A significant gender difference was found in activation of the left and right STG (BA22) and the cingulate cortex for the subtractive condition women minus men, thus indicating that women might have a greater preference or interest for social stimuli (faces and persons). http://www.biomedcentral.com/1471-2202/9/56 Alice M Proverbio, Alberto Zani and Roberta Adorni BMC Neuroscience 2008, 9:56 Number of accesses: 251 2008-06-30 doi:10.1186/1471-2202-9-56 BMC Neuroscience 1471-2202 9 56 2008-06-30 Dynamic modeling and simulation of signal transduction pathways is an important topic in systems biology and is obtaining growing attention from researchers with experimental or theoretical background. Here we review attempts to analyze and model specific signaling systems. We review the structure of recurrent building blocks of signaling pathways and their integration into more comprehensive models, which enables the understanding of complex cellular processes. The variety of mechanisms found and modeling techniques used are illustrated with models of different signaling pathways. Focusing on the close interplay between experimental investigation of pathways and the mathematical representations of cellular dynamics, we discuss challenges and perspectives that emerge in studies of signaling systems. http://www.biomedcentral.com/1471-2202/7/S10 Edda Klipp and Wolfram Liebermeister BMC Neuroscience 2006, 7:S10 Number of accesses: 248 2006-10-30 doi:10.1186/1471-2202-7-S1-S10 BMC Neuroscience 1471-2202 7 S10 2006-10-30 Background: 3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) is known for its toxicological, psychopathological and abuse potential. Some environmental conditions, e.g. acoustic stimulation typical of the "rave scene" can influence the toxicity of this drug. Results: We investigated the effects of low doses of MDMA in vivo using Wistar rats in the absence of acoustic stimulation (white noise; 95 Db) demonstrating that ecstasy is able to induce a significant activation (reduction of Electrocortical total power) of the telencephalic cortex that spontaneously reverts in the absence of sensorial stimuli, whereas it persists for several days if, in addition to MDMA, the animals are exposed to acoustic stimulation. Conclusion: Our data demonstrate that low doses of MDMA are able to reduce electrocortical total power, and that this effect is potentiated by sensorial stimuli commonly present in certain environments, such as rave parties. http://www.biomedcentral.com/1471-2202/7/13 Michelangelo Iannone, Stefania Bulotta, Donatella Paolino, Maria Cristina Zito, Santo Gratteri, Francesco S Costanzo and Domenicantonio Rotiroti BMC Neuroscience 2006, 7:13 Number of accesses: 246 2006-02-16 doi:10.1186/1471-2202-7-13 BMC Neuroscience 1471-2202 7 13 2006-02-16