http://www.neuralsystemsandcircuits.com The latest research articles published by Neural Systems & Circuits 2012-01-30T00:00:00Z The development of neuroscience over the last 50 years has some similarities with the development of physics in the 17th Century. Towards the beginning of that century Bacon promoted the systematic gathering of experimental data and the induction of scientific truth; towards the end Newton expressed his principles of gravitation and motion in a concise set of mathematical equations that made precise falsifiable predictions. This paper expresses the opinion that as neuroscience comes of age it needs to move away from amassing large quantities of data about the brain, and adopt a Popperian model in which theories are developed that can make strong falsifiable predictions and guide future experimental work. http://www.neuralsystemsandcircuits.com/content/2/1/2 David Gamez Neural Systems & Circuits 2012, null:2 2012-01-30T00:00:00Z doi:10.1186/2042-1001-2-2 /content/figures/2042-1001-2-2-toc.gif Neural Systems & Circuits 2042-1001 ${item.volume} 2 2012-01-30T00:00:00Z PDF No description available http://www.neuralsystemsandcircuits.com/content/2/1/1 Peter Latham Venkatesh Murthy Neural Systems & Circuits 2012, null:1 2012-01-05T00:00:00Z doi:10.1186/2042-1001-2-1 /content/figures/2042-1001-2-1-toc.gif Neural Systems & Circuits 2042-1001 ${item.volume} 1 2012-01-05T00:00:00Z XML BackgroundThe primary visual cortex of many mammals contains a continuous representation of visual space, with a roughly repetitive aperiodic map of orientation preferences superimposed. It was recently found that orientation preference maps (OPMs) obey statistical laws which are apparently invariant among species widely separated in eutherian evolution. Here, we examine whether one of the most prominent models for the optimization of cortical maps, the elastic net (EN) model, can reproduce this common design. The EN model generates representations which optimally trade of stimulus space coverage and map continuity. While this model has been used in numerous studies, no analytical results about the precise layout of the predicted OPMs have been obtained so far.ResultsWe present a mathematical approach to analytically calculate the cortical representations predicted by the EN model for the joint mapping of stimulus position and orientation. We find that in all the previously studied regimes, predicted OPM layouts are perfectly periodic. An unbiased search through the EN parameter space identifies a novel regime of aperiodic OPMs with pinwheel densities lower than found in experiments. In an extreme limit, aperiodic OPMs quantitatively resembling experimental observations emerge. Stabilization of these layouts results from strong nonlocal interactions rather than from a coverage-continuity-compromise.ConclusionsOur results demonstrate that optimization models for stimulus representations dominated by nonlocal suppressive interactions are in principle capable of correctly predicting the common OPM design. They question that visual cortical feature representations can be explained by a coverage-continuity-compromise. http://www.neuralsystemsandcircuits.com/content/1/1/17 Wolfgang Keil Fred Wolf Neural Systems & Circuits 2011, null:17 2011-12-29T00:00:00Z doi:10.1186/2042-1001-1-17 /content/figures/2042-1001-1-17-toc.gif Neural Systems & Circuits 2042-1001 ${item.volume} 17 2011-12-29T00:00:00Z XML Although it has been over a century since neuroscientists first conjectured that networks of neurons comprise the brain, technology has limited high-throughput investigations of neural circuitry until very recently. In the last couple of decades, several experimental paradigms have arisen that are poised to finally begin studying neuroanatomy in a high-throughput fashion. In 2005, the term connectome was coined independently by Patric Hagmann and Olaf Sporns, to describe the complete set of neural connections in a brain. Interestingly, both usages seemed to be referring to using Magnetic Resonance Imaging (MRI) to study human brain networks. Shortly thereafter, Narayanan "Bobby" Kasthuri and Jeff Lichtman published an article suggesting that "connectome" should refer to connections between neurons, which one can infer using Electron Microscopy (EM) and fluorescence microscopy (e.g., brainbow animals). "Projectome", they suggested, is more appropriate for MRI based studies. Yet, the word connectome stuck, and now refers to essentially any neuroscientific investigation of the relationship between (collections of) neurons, be they functional or structural. http://www.neuralsystemsandcircuits.com/content/1/1/16 Joshua Vogelstein Neural Systems & Circuits 2011, null:16 2011-11-18T00:00:00Z doi:10.1186/2042-1001-1-16 /content/figures/2042-1001-1-16-toc.gif Neural Systems & Circuits 2042-1001 ${item.volume} 16 2011-11-18T00:00:00Z XML The 2011 EMBO Conference Series on the Assembly and Function of Neuronal Circuits was held from 25 to 30 September 2011 at Monte Verità in Ascona, Switzerland. Approximately 100 participants explored current challenges and approaches to studying neural circuit function and organization. http://www.neuralsystemsandcircuits.com/content/1/1/15 Alice Wang Jeremiah Cohen Neural Systems & Circuits 2011, null:15 2011-10-27T00:00:00Z doi:10.1186/2042-1001-1-15 /content/figures/2042-1001-1-15-toc.gif Neural Systems & Circuits 2042-1001 ${item.volume} 15 2011-10-27T00:00:00Z XML - http://www.neuralsystemsandcircuits.com/content/1/1/14 Anna Webb Peter Latham Venkatesh Murthy Neural Systems & Circuits 2011, null:14 2011-10-06T00:00:00Z doi:10.1186/2042-1001-1-14 /content/figures/2042-1001-1-14-toc.gif Neural Systems & Circuits 2042-1001 ${item.volume} 14 2011-10-06T00:00:00Z XML In the study of the neural circuits underlying behavior and autonomic functions, the stereotyped and accessible nervous system of medicinal leeches, Hirudo sp., has been particularly informative. These leeches express well-defined behaviors and autonomic movements which are amenable to investigation at the circuit and neuronal levels. In this review, we discuss some of the best understood of these movements and the circuits which underlie them, focusing on swimming, crawling and heartbeat. We also discuss the rudiments of decision-making: the selection between generally mutually exclusive behaviors at the neuronal level. http://www.neuralsystemsandcircuits.com/content/1/1/13 Damon Lamb Ronald Calabrese Neural Systems & Circuits 2011, null:13 2011-09-28T00:00:00Z doi:10.1186/2042-1001-1-13 /content/figures/2042-1001-1-13-toc.gif Neural Systems & Circuits 2042-1001 ${item.volume} 13 2011-09-28T00:00:00Z XML - http://www.neuralsystemsandcircuits.com/content/1/1/12 Geoffrey Hinton Neural Systems & Circuits 2011, null:12 2011-08-15T00:00:00Z doi:10.1186/2042-1001-1-12 /content/figures/2042-1001-1-12-toc.gif Neural Systems & Circuits 2042-1001 ${item.volume} 12 2011-08-15T00:00:00Z XML The environment has a central role in shaping developmental trajectories and determining the phenotype so that animals are adapted to the specific conditions they encounter. Epigenetic mechanisms can have many effects, with changes in the nervous and musculoskeletal systems occurring at different rates. How is the function of an animal maintained whilst these transitions happen? Phenotypic plasticity can change the ways in which animals respond to the environment and even how they sense it, particularly in the context of social interactions between members of their own species. In the present article, we review the mechanisms and consequences of phenotypic plasticity by drawing upon the desert locust as an unparalleled model system. Locusts change reversibly between solitarious and gregarious phases that differ dramatically in appearance, general physiology, brain function and structure, and behaviour. Solitarious locusts actively avoid contact with other locusts, but gregarious locusts may live in vast, migrating swarms dominated by competition for scarce resources and interactions with other locusts. Different phase traits change at different rates: some behaviours take just a few hours, colouration takes a lifetime and the muscles and skeleton take several generations. The behavioural demands of group living are reflected in gregarious locusts having substantially larger brains with increased space devoted to higher processing. Phase differences are also apparent in the functioning of identified neurons and circuits. The whole transformation process of phase change pivots on the initial and rapid behavioural decision of whether or not to join with other locusts. The resulting positive feedback loops from the presence or absence of other locusts drives the process to completion. Phase change is accompanied by dramatic changes in neurochemistry, but only serotonin shows a substantial increase during the critical one- to four-hour window during which gregarious behaviour is established. Blocking the action of serotonin or its synthesis prevents the establishment of gregarious behaviour. Applying serotonin or its agonists promotes the acquisition of gregarious behaviour even in a locust that has never encountered another locust. The analysis of phase change in locusts provides insights into a feedback circuit between the environment and epigenetic mechanisms and more generally into the neurobiology of social interaction. http://www.neuralsystemsandcircuits.com/content/1/1/11 Malcolm Burrows Stephen Rogers Swidbert Ott Neural Systems & Circuits 2011, null:11 2011-07-26T00:00:00Z doi:10.1186/2042-1001-1-11 /content/figures/2042-1001-1-11-toc.gif Neural Systems & Circuits 2042-1001 ${item.volume} 11 2011-07-26T00:00:00Z XML no abstract http://www.neuralsystemsandcircuits.com/content/1/1/10 George Kemenes Neural Systems & Circuits 2011, null:10 2011-07-26T00:00:00Z doi:10.1186/2042-1001-1-10 /content/figures/2042-1001-1-10-toc.gif Neural Systems & Circuits 2042-1001 ${item.volume} 10 2011-07-26T00:00:00Z XML