Physiological and psychophysical evidence for temporal coding of sensory qualities in different modalities is considered. A space of pulse codes is outlined that includes 1) channel-codes ...(across-neural activation patterns), 2) temporal pattern codes (spike patterns), and 3) spike latency codes (relative spike timings). Temporal codes are codes in which spike timings (rather than spike counts) are critical to informational function. Stimulus-dependent temporal patterning of neural responses can arise extrinsically or intrinsically: through stimulus-driven temporal correlations (phase-locking), response latencies, or characteristic timecourses of activation. Phase-locking is abundant in audition, mechanoception, electroception, proprioception, and vision. In phase-locked systems, temporal differences between sensory surfaces can subserve representations of location, motion, and spatial form that can be analyzed via temporal cross-correlation operations. To phase-locking limits, patterns of all-order interspike intervals that are produced reflect stimulus autocorrelation functions that can subserve representations of form. Stimulus-dependent intrinsic temporal response structure is found in all sensory systems. Characteristic temporal patterns that may encode stimulus qualities can be found in the chemical senses, the cutaneous senses, and some aspects of vision. In some modalities (audition, gustation, color vision, mechanoception, nocioception), particular temporal patterns of electrical stimulation elicit specific sensory qualities.
Abstract
The current shift of fishery efforts towards the deep sea is raising concern about the vulnerability of deep-water sharks, which are often poorly studied and characterized by problematic ...taxonomy. For instance, in the Mediterranean Sea the taxonomy of genus Centrophorus has not been clearly unravelled yet. Since proper identification of the species is fundamental for their correct assessment and management, this study aims at clarifying the taxonomy of this genus in the Mediterranean Basin through an integrated taxonomic approach. We analysed a total of 281 gulper sharks (Centrophorus spp.) collected from various Mediterranean, Atlantic and Indian Ocean waters. Molecular data obtained from cytochrome c oxidase subunit I (COI), 16S ribosomal RNA (16S), NADH dehydrogenase subunit 2 (ND2) and a portion of a nuclear 28S ribosomal DNA gene region (28S) have highlighted the presence of a unique mitochondrial clade in the Mediterranean Sea. The morphometric results confirmed these findings, supporting the presence of a unique and distinct morphological group comprising all Mediterranean individuals. The data strongly indicate the occurrence of a single Centrophorus species in the Mediterranean, ascribable to C. cf. uyato, and suggest the need for a revision of the systematics of the genus in the area.
Objective. Cyclosporin A (CsA) is an effective agent in rheumatoid arthritis (RA), slowing joint damage progression. Its therapeutic effect on T lymphocytes has been studied extensively, but there is ...little information available about neutrophils, the cells responsible for a substantial proportion of inflammation. A study was performed to investigate the in vitro effects of CsA on neutrophil functions triggered by several agonists and determine whether the drug could counteract the binding of formyl‐methionyl‐leucyl‐phenylalanine (fMLP) to its receptor and/or modulate changes in the intracellular Ca2+ concentration (Ca2+i). Methods. CsA was added to neutrophils 5–50 min before the incubation steps for neutrophil function assays (chemotaxis, superoxide anion production, lysozyme release), calcium measurements and receptor binding experiments. Results. CsA appeared to be particularly effective in lowering chemotaxis, superoxide anion production and lysozyme release induced by different agonists. However, it did not significantly affect either basal or agonist‐stimulated neutrophil Ca2+i and the interaction between fMLP and its receptor. Conclusions. Because of its in vitro inhibition of neutrophil functions, CsA appears to have considerable potential as an anti‐inflammatory drug. Moreover, as it is also a potent immunosuppressive agent, it may reduce the progression of joint damage in RA. More work remains to be done to clarify the molecular mechanism of CsA action on neutrophils.
Extradimensional bypass Cariani, Peter A.
BioSystems,
2002, 2002-Jan, 2002-1-00, 20020101, Volume:
64, Issue:
1
Journal Article
Peer reviewed
We discuss the concept of extradimensional bypass as it was developed by the late theoretical biologist Michael Conrad. An evolving system that optimizes its performance by gradient ascent (hill ...climbing) can avoid being trapped in local maxima by increasing the effective dimensionality of its search space. Many local maxima may become saddle points in the higher dimensional space, such that gradient ascent can continue unimpeded. Extradimensional bypass as a concept has parallels in theories of open-ended learning and functional emergence, where new structural, functional, and informational primitives can increase the effective dimensionality of material systems.
We Aimed to analyze the in vitro function of isolated and cryopreserved human hepatocytes (CHH) from a cell bank and to define their potential clinical application in a bioartificial liver (BAL) ...device.
Over 24 months, 103 not transplantable livers were utilized for human hepatocytes isolation and cryopreservation. Hepatocytes isolated by collagenase were analyzed for yield, viability, diazepam metabolism, and production of human albumin after isolation and cryopreservation in LN
2.
The causes for refusal for transplantation were macrosteatosis >60%, ischemic damage due to donor hypotension, and nonviral cirrhosis in 60%, 11%, and 8%, respectively. Cell yields averaged 7 million hepatocytes per gram of liver of mean viability of 80% ± 13%. The viability of CHH after thawing averaged 50%. Thawed hepatocytes showed diazepam metabolism, and human albumin synthesis comparable to fresh cells. CHH were utilized as the biological component of a BAL for temporary support as three applications of two patients affected by fulminant hepatic failure awaiting urgent transplant. Ten to 13 billion viable CHH were loaded into each BAL. Liver function showed bilirubin and ammonia reduction at the end of each treatment. One patient was successfully bridged to emergency OLTx after one BAL; in the second case there was spontaneous recovery of liver function after two BAL.
Recovery of donor human livers unwanted for transplantation allowed isolation and cryopreservation of viable and functionally active human hepatocytes, which have been banked and successfully used for clinical applications of a BAL device.
Human T-cell lymphotropic virus type I (HTLV-I) is a human retrovirus and the aetiological agent of a progressive neurological disease called tropical spastic paraparesis/HTLV-I-associated myelopathy ...(TSP/HAM), as confirmed by evidence accumulated in HTLV-I seroprevalence studies. TSP/HAM is rarely diagnosed in Italy, given the low prevalence of HTLV-I in the population. TSP/HAM begins insidiously in the fourth decade, mainly with spastic paraparesis of the lower extremities and positive Babinski reflex, as well as interfering with bowel and bladder functions. In this study we report the clinical, virological and haemato chemical data of a 54-year-old woman, born in the Ivory Cost, with symptoms suggestive of TSP. The presence of HTLV-I infection was demonstrated by the detection of antibodies in serum and in cerebrospinal fluid by immunoenzymatic assay and Western blot analysis. In addition, viral isolation was carried out in peripheral blood cells, and the presence of HTLV-I proviral DNA was confirmed by polymerase chain reaction/Southern blot and sequencing analysis. According to our results, HTLV-I testing might be useful when TSP/HAM is suspected.
The smooth-hounds represent a significant proportion of the elasmobranch catch in the Adriatic basin of the Mediterranean Sea, where the common (Mustelus mustelus) and blackspotted (Mustelus ...punctulatus) smooth-hounds co-occur. The 2 species share several morphological and morphometric characters that lead to frequent misidentification. In order to provide information useful for their species identification, we performed a morphological identification of several Mustelus specimens to select individuals unambiguously attributed to 1 of the 2 species, and assayed these with 3 new molecular tests. First, we developed and validated a mitochondrial DNA assay based on species-specific amplification of the cytochrome c oxidase subunit 1 (COI). Second, a fragment analysis of 15 microsatellites cross-amplified from several triakid species was performed to identify diagnostic loci. Finally, a length difference was identified in the internal transcribed spacer 2 (ITS2) region and a diagnostic test based on its amplification was established. All the samples classified morphologically as M. mustelus and M. punctulatus showed a species-specific profile using all the 3 molecular tests. In addition, cross-amplification of microsatellites allowed identification of 9 highly polymorphic loci that will be useful for the study of the mating system and population differentiation of the 2 species.
A roadmap for the study of conscious audition and its neural basis Dykstra, Andrew R.; Cariani, Peter A.; Gutschalk, Alexander
Philosophical transactions of the Royal Society of London. Series B. Biological sciences,
02/2017, Volume:
372, Issue:
1714
Journal Article
Peer reviewed
How and which aspects of neural activity give rise to subjective perceptual experience—i.e. conscious perception—is a fundamental question of neuroscience. To date, the vast majority of work ...concerning this question has come from vision, raising the issue of generalizability of prominent resulting theories. However, recent work has begun to shed light on the neural processes subserving conscious perception in other modalities, particularly audition. Here, we outline a roadmap for the future study of conscious auditory perception and its neural basis, paying particular attention to how conscious perception emerges (and of which elements or groups of elements) in complex auditory scenes. We begin by discussing the functional role of the auditory system, particularly as it pertains to conscious perception. Next, we ask: what are the phenomena that need to be explained by a theory of conscious auditory perception? After surveying the available literature for candidate neural correlates, we end by considering the implications that such results have for a general theory of conscious perception as well as prominent outstanding questions and what approaches/techniques can best be used to address them. This article is part of the themed issue 'Auditory and visual scene analysis'.
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