Motion-sensitive responses in visual area V4 in the absence of primary visual cortex

Neurons in cortical ventral-stream area V4 are thought to contribute to important aspects of visual processing by integrating information from primary visual cortex (V1). However, how V4 neurons respond to visual stimulation after V1 injury remains unclear: While electrophysiological investigation of V4 neurons during reversible V1 inactivation suggests that virtually all responses are eliminated (Girard et al., 1991), fMRI in humans and monkeys with permanent lesions shows reliable V1-independent activity (Baseler et al., 1999; Goebel et al., 2001; Schmid et al., 2010). To resolve this apparent discrepancy, we longitudinally assessed neuronal functions of macaque area V4 using chronically implanted electrode arrays before and after creating a permanent aspiration lesion in V1. During the month after lesioning, we observed weak yet significant spiking activity in response to stimuli presented to the lesion-affected part of the visual field. These V1-independent responses showed sensitivity for motion and likely reflect the effect of V1-bypassing geniculate input into extrastriate areas

Detection of pulse trains in the electrically stimulated cochlea: Effects of cochlear health

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98659/1/JAS003954.pd

The megalithic building of S.Erasmo di Cesi: architecture, astronomy, and landscape

Abstract. One of the most enigmatic megalithic buildings of Italy is the structure which lies on the S. Erasmo hill near Cesi, in Umbria, a huge complex encompassing an area of around 8000 square meters and enclosed by refined cyclopean walls. Although its date is uncertain, suggested dates comprise the Iron Age and archaic period, down to the third century B.C. The building’s function is also uncertain. Usually identified as a fortified structure, in fact there is a megalithic platform at the southern end of the enclosure which could have served as foundation of a temple or palace and, from the top of Monte Torre Maggiore, a complex of temples dating from the fourth century B.C. overlooks the hill. Similar combinations of megalithic buildings resting half-way to temples placed on high peaks are known to exist. In order to clarify the function of this structure and its position in relation to the surrounding landscape, with particular attention to its visibility and to the directions of visibility from the complex, as well as to the possible astronomical alignments, we present a multi-disciplinary approach to the study of the S. Erasmo complex, which includes the mapping of the sky at the various possible epochs of construction, the creation of a digital model of the landscape in forms of digital maps using Geographic Information System technologies, and a 3D model using various 3D software packages

CD55 Deficiency Protects against Atherosclerosis in ApoE-Deficient Mice via C3a Modulation of Lipid Metabolism

Atherosclerosis, the leading cause of death in the Western world, is driven by chronic inflammation within the artery wall. Elements of the complement cascade are implicated in the pathogenesis, because complement proteins and their activation products are found in the atherosclerotic plaque. We examined the role of CD55, a membrane inhibitor of the complement component 3 (C3) convertase, which converts C3 into C3a and C3b, in atherosclerosis. CD55-deficient (CD55−/−) mice were crossed onto the atherosclerosis-prone apolipoprotein E (apoE)-deficient (apoE−/−) background. High fat–fed male apoE−/−/CD55−/− mice were strongly protected from developing atherosclerosis compared with apoE−/− controls. Lipid profiling showed significantly lower levels of triglycerides, nonesterified fatty acids, and cholesterol in apoE−/−/CD55−/− mice than that in controls after high-fat feeding, whereas body fat in apoE−/−/CD55−/− mice content was increased. Plasma levels of C3 fell, whereas concentrations of C3adesArg (alias acylation stimulating protein; ASP), produced by serum carboxypeptidase N–mediated desargination of C3a, increased in nonfasted high fat–fed apoE−/−/CD55−/− mice, indicating complement activation. Thus, complement dysregulation in the absence of CD55 provoked increased C3adesArg production that, in turn, caused altered lipid handling, resulting in atheroprotection and increased adiposity. Interventions that target complement activation in adipose tissue should be explored as lipid-decreasing strategies

Neural Synchrony during Response Production and Inhibition

Inhibition of irrelevant information (conflict monitoring) and/or of prepotent actions is an essential component of adaptive self-organized behavior. Neural dynamics underlying these functions has been studied in humans using event-related brain potentials (ERPs) elicited in Go/NoGo tasks that require a speeded motor response to the Go stimuli and withholding a prepotent response when a NoGo stimulus is presented. However, averaged ERP waveforms provide only limited information about the neuronal mechanisms underlying stimulus processing, motor preparation, and response production or inhibition. In this study, we examine the cortical representation of conflict monitoring and response inhibition using time-frequency analysis of electroencephalographic (EEG) recordings during continuous performance Go/NoGo task in 50 young adult females. We hypothesized that response inhibition would be associated with a transient boost in both temporal and spatial synchronization of prefrontal cortical activity, consistent with the role of the anterior cingulate and lateral prefrontal cortices in cognitive control. Overall, phase synchronization across trials measured by Phase Locking Index and phase synchronization between electrode sites measured by Phase Coherence were the highest in the Go and NoGo conditions, intermediate in the Warning condition, and the lowest under Neutral condition. The NoGo condition was characterized by significantly higher fronto-central synchronization in the 300–600 ms window, whereas in the Go condition, delta- and theta-band synchronization was higher in centro-parietal regions in the first 300 ms after the stimulus onset. The present findings suggest that response production and inhibition is supported by dynamic functional networks characterized by distinct patterns of temporal and spatial synchronization of brain oscillations

Age-Related Changes of Myelin Basic Protein in Mouse and Human Auditory Nerve

Age-related hearing loss (presbyacusis) is the most common type of hearing impairment. One of the most consistent pathological changes seen in presbyacusis is the loss of spiral ganglion neurons (SGNs). Defining the cellular and molecular basis of SGN degeneration in the human inner ear is critical to gaining a better understanding of the pathophysiology of presbyacusis. However, information on age-related cellular and molecular alterations in the human spiral ganglion remains scant, owing to the very limited availably of human specimens suitable for high resolution morphological and molecular analysis. This study aimed at defining age-related alterations in the auditory nerve in human temporal bones and determining if immunostaining for myelin basic protein (MBP) can be used as an alternative approach to electron microscopy for evaluating myelin degeneration. For comparative purposes, we evaluated ultrastructural alternations and changes in MBP immunostaining in aging CBA/CaJ mice. We then examined 13 temporal bones from 10 human donors, including 4 adults aged 38–46 years (middle-aged group) and 6 adults aged 63–91 years (older group). Similar to the mouse, intense immunostaining of MBP was present throughout the auditory nerve of the middle-aged human donors. Significant declines in MBP immunoreactivity and losses of MBP+ auditory nerve fibers were observed in the spiral ganglia of both the older human and aged mouse ears. This study demonstrates that immunostaining for MBP in combination with confocal microscopy provides a sensitive, reliable, and efficient method for assessing alterations of myelin sheaths in the auditory nerve. The results also suggest that myelin degeneration may play a critical role in the SGN loss and the subsequent decline of the auditory nerve function in presbyacusis

Soil vs. glass: an integrated approach towards the characterization of soil as a burial environment for the glassware of Cucagna Castle (Friuli, Italy)

This research is performed on a selection of archaeological glass finds with corresponding soil samples, excavated on the site of the High Medieval castle Cucagna in Friuli/Northern Italy. In the frame of understanding medieval glass technology and the chemical-physical conditions that influenced the state of preservation of the glass finds, this study uses a multi-analytical line-up of methods to characterize the composition of the glass and basic parameters of the soil including texture, mineralogical composition, pH, redox potential (Eh) and electric conductivity (EC). The results show that glass corrosion in soil not only depends on acidity, alkalinity or glass composition but also on the texture of the soil, measurable as grain-size distribution, and the mineralogical composition. The compositional groups of the glassware from Cucagna indicate the use of various raw material sources, pointing to Northern and Central Italian glass workshops with primary or secondary glass production.[GRAPHICS].FdA – Publicaties zonder aanstelling Universiteit Leide

Late Quaternary sea-level change and early human societies in the central and eastern Mediterranean Basin : an interdisciplinary review

This article reviews key data and debates focused on relative sea-level changes since the Last Interglacial (approximately the last 132,000 years) in the Mediterranean Basin, and their implications for past human populations. Geological and geomorphological landscape studies are critical to archaeology. Coastal regions provide a wide range of resources to the populations that inhabit them. Coastal landscapes are increasingly the focus of scholarly discussions from the earliest exploitation of littoral resources and early hominin cognition, to the inundation of the earliest permanently settled fishing villages and eventually, formative centres of urbanisation. In the Mediterranean, these would become hubs of maritime transportation that gave rise to the roots of modern seaborne trade. As such, this article represents an original review of both the geo-scientific and archaeological data that specifically relate to sea-level changes and resulting impacts on both physical and cultural landscapes from the Palaeolithic until the emergence of the Classical periods. Our review highlights that the interdisciplinary links between coastal archaeology, geomorphology and sea-level changes are important to explain environmental impacts on coastal human societies and human migration. We review geological indicators of sea level and outline how archaeological features are commonly used as proxies for measuring past sea levels, both gradual changes and catastrophic events. We argue that coastal archaeologists should, as a part of their analyses, incorporate important sea-level concepts, such as indicative meaning. The interpretation of the indicative meaning of Roman fishtanks, for example, plays a critical role in reconstructions of late Holocene Mediterranean sea levels. We identify avenues for future work, which include the consideration of glacial isostatic adjustment (GIA) in addition to coastal tectonics to explain vertical movements of coastlines, more research on Palaeolithic island colonisation, broadening of Palaeolithic studies to include materials from the entire coastal landscape and not just coastal resources, a focus on rescue of archaeological sites under threat by coastal change, and expansion of underwater archaeological explorations in combination with submarine geomorphology. This article presents a collaborative synthesis of data, some of which have been collected and analysed by the authors, as the MEDFLOOD (MEDiterranean sea-level change and projection for future FLOODing) community, and highlights key sites, data, concepts and ongoing debates