Search results for "Neuronal"

Crane collision modelling using a neural network approach

2004

Abstract The objective of the present work is to find a Collision Detection algorithm to be used in the Virtual Reality crane simulator (UVSim®), developed by the Robotics Institute of the University of Valencia for the Port of Valencia. The method is applicable to box-shaped objects and is based on the relationship between the colliding object positions and their impact points. The tool chosen to solve the problem is a neural network, the multilayer perceptron, which adapts to the characteristics of the problem, namely, non-linearity, a large amount of data, and no a priori knowledge. The results achieved by the neural network are very satisfactory for the case of box-shaped objects. Furth…

The brainstem efferent acoustic chiasm in pigmented and albino rats

2015

Abstract The present study examined whether structural peculiarities in the brain-efferent pathway to the organ of Corti may underlie functional differences in hearing between pigmented and albino individuals of the same mammalian species. Pigmented Brown-Norway rats and albino Wistar rats received unilateral injections of an aqueous solution of the retrograde neuronal tracer Fluorogold (FG) into the scala tympani of the cochlea to identify olivocochlear neurons (OCN) in the brainstem superior olivary complex. After five days, brains were perfusion-fixed and brainstem sections were cut and analyzed with respect to retrogradely labeled neurons. Intrinsic neurons of the lateral system were lo…

Both attention and prediction are necessary for adaptive neuronal tuning in sensory processing

2014

International audience; The brain as a proactive system processes sensory information under the top-down influence of attention and prediction. However, the relation between attention and prediction remains undetermined given the conflation of these two mechanisms in the literature. To evaluate whether attention and prediction are dependent of each other, and if so, how these two top-down mechanisms may interact in sensory processing, we orthogonally manipulated attention and prediction in a target detection task. Participants were instructed to pay attention to one of two interleaved stimulus streams of predictable/unpredictable tone frequency. We found that attention and prediction intera…

NEURONAL FACTOR SECRETED THROUGH UNUSUAL PATHWAYS ARE PROBABLY INVOLVED IN BLOOD BRAIN BARRIER (BBB) FORMATION.

2004

The neuronal ceroid-lipofuscinoses: A historical introduction

2013

AbstractThe neuronal ceroid-lipofuscinoses (Batten disease) collectively constitute one of the most common groups of inherited childhood onset neurodegenerative disorders, and have also been identified in many domestic and laboratory animals. The group of human neuronal ceroid-lipofuscinoses currently comprises 14 genetically distinct disorders, mostly characterised by progressive mental, motor and visual deterioration with onset in childhood or adolescence. Abnormal autofluorescent, electron-dense granules accumulate in the cytoplasm of nerve cells, and this storage process is associated with selective destruction and loss of neurons in the brain and retina. The present paper outlines near…

Differential efferent projections of the anterior, posteroventral, and posterodorsal subdivisions of the medial amygdala in mice

2012

The medial amygdaloid nucleus (Me) is a key structure in the control of sociosexual behaviour in mice. It receives direct projections from the main and accessory olfactory bulbs, as well as an important hormonal input. To better understand its behavioural role, in this work we investigate the structures receiving information from the Me, by analysing the efferent projections from its anterior (MeA), posterodorsal (MePD) and posteroventral (MePV) subdivisions, using anterograde neuronal tracing with biotinylated and tetrametylrhodamine-conjugated dextranamines.The Me is strongly interconnected with the rest of the chemosensory amygdala, but shows only moderate projections to the central nucl…

Role of non-neuronal and neuronal acetylcholine in the airways

2001

It is well known that acetylcholine represents a dominant neurotransmitter within mammalian airways and that airway functions, like smooth muscle activity and secretion, are under a continuous cholinergic tone. However, the teleology of this basal cholinergic tone, assumed to originate from neuronal activity, appears difficult to understand, whereas neuronal cholinergic reflex activity can be regarded as a rational regulatory pathway to protect the airways from injury [1-3]. Based on recent experimental observations, both phenomena may reflect two different biological roles of acetylcholine, acting first as a universal cytomolecule (non-neuronal) and second as a classical neurotransmitter (…

Minireview: pH and synaptic transmission

2013

AbstractAs a general rule a rise in pH increases neuronal activity, whereas it is dampened by a fall of pH. Neuronal activity per se also challenges pH homeostasis by the increase of metabolic acid equivalents. Moreover, the negative membrane potential of neurons promotes the intracellular accumulation of protons. Synaptic key players such as glutamate receptors or voltage-gated calcium channels show strong pH dependence and effects of pH gradients on synaptic processes are well known. However, the processes and mechanisms that allow controlling the pH in synaptic structures and how these mechanisms contribute to normal synaptic function are only beginning to be resolved.

Microglial involvement in neuroplastic changes following focal brain ischemia in rats.

2009

The pathogenesis of ischemic stroke is a complex sequence of events including inflammatory reaction, for which the microglia appears to be a major cellular contributor. However, whether post-ischemic activation of microglial cells has beneficial or detrimental effects remains to be elucidated, in particular on long term brain plasticity events. The objective of our study was to determine, through modulation of post-stroke inflammatory response, to what extent microglial cells are involved in some specific events of neuronal plasticity, neurite outgrowth and synaptogenesis. Since microglia is a source of neurotrophic factors, the identification of the brain-derived neurophic factor (BDNF) as…

Contributed discussion on article by Pratola [Comment on "M.T. Pratola, Efficient metropolis-hastings proposal mechanisms for Bayesian regression tre…

2016

Contains fulltext : 161650.pdf (Publisher’s version ) (Open Access) The author should be commended for his outstanding contribution to the literature on Bayesian regression tree models. The author introduces three innovative sampling approaches which allow for efficient traversal of the model space. In this response, we add a fourth alternative. 3 p.