scholarly journals Mathematical Study of the Role of Delta/Notch Lateral Inhibition during Primary Branching of Drosophila Trachea Development

2012 ◽  
Vol 103 (12) ◽  
pp. 2549-2559 ◽  
Author(s):  
Yoshiki Koizumi ◽  
Yoh Iwasa ◽  
Tsuyoshi Hirashima
Keyword(s):  
Lateral Inhibition ◽  
Mathematical Study ◽  
Drosophila Trachea

The role of early retinal lateral inhibition: More than maximizing luminance information

2000 ◽  
Vol 17 (1) ◽  
pp. 77-89 ◽  
Author(s):  
ROSARIO M. BALBOA ◽  
NORBERTO M. GRZYWACZ
Keyword(s):  
Lateral Inhibition ◽  
Visual Processing ◽  
Visual Information ◽  
Receptive Fields ◽  
Plexiform Layer ◽  
Biological Data ◽  
Natural Images ◽  
Photon Absorption ◽  
Biological Behavior

Lateral inhibition is one of the first and most important stages of visual processing. There are at least four theories related to information theory in the literature for the role of early retinal lateral inhibition. They are based on the spatial redundancy in natural images and the advantage of removing this redundancy from the visual code. Here, we contrast these theories with data from the retina's outer plexiform layer. The horizontal cells' lateral-inhibition extent displays a bell-shape behavior as function of background luminance, whereas all the theories show a fall as luminance increases. It is remarkable that different theories predict the same luminance behavior, explaining “half” of the biological data. We argue that the main reason is how these theories deal with photon-absorption noise. At dim light levels, for which this noise is relatively large, large receptive fields would increase the signal-to-noise ratio through averaging. Unfortunately, such an increase at low luminance levels may smooth out basic visual information of natural images. To explain the biological behavior, we describe an alternate hypothesis, which proposes that the role of early visual lateral inhibition is to deal with noise without missing relevant clues from the visual world, most prominently, the occlusion boundaries between objects.

ROLE OF MIGRATORY BIRDS UNDER ENVIRONMENTAL FLUCTUATION — A MATHEMATICAL STUDY

2008 ◽  
Vol 16 (01) ◽  
pp. 81-106 ◽  
Author(s):  
SAMRAT CHATTERJEE ◽  
S. PAL ◽  
J. CHATTOPADHYAY
Keyword(s):  
Migratory Birds ◽  
Threshold Value ◽  
Disease Spread ◽  
Control Procedure ◽  
Mathematical Study ◽  
Environmental Fluctuation ◽  
Environmental Disturbances ◽  
Proposed Model ◽  
Account Standard

Chatterjee and Chattopadhyay1proposed and analyzed a simple one season eco-epidemiological model to understand the role of migratory birds in an eco-epidemiological scenario. In this paper, we have modified their model taking into account standard incidence as horizontal incidence. We have studied the proposed model both in the absence and in the presence of environmental disturbances. From our analysis, we observe that in the absence of the environmental fluctuations, the disease spread by migratory birds may be controlled by either decreasing the contact rate, or increasing the recovery or predation rates. Further, we also observe that if the artificial eutrophication (or intensity of white noise) is kept under a certain threshold value, the control procedure proposed in the deterministic case is also valid in the presence of environmental disturbances.

scholarly journals Dendritic integration in olfactory bulb granule cells: Thresholds for lateral inhibition and role of active conductances upon simultaneous activation

2020 ◽  
Author(s):  
Max Müller ◽  
Veronica Egger
Keyword(s):  
Olfactory Bulb ◽  
Lateral Inhibition ◽  
Granule Cells ◽  
Brain Slices ◽  
Dendritic Integration ◽  
Two Photon ◽  
Channel Inactivation ◽  
Cell Recording ◽  
Simultaneous Activation

AbstractThe inhibitory axonless olfactory bulb granule cells (GCs) form reciprocal dendrodendritic synapses with mitral and tufted cells via large spines, mediating recurrent and lateral inhibition. Rat GC dendrites are excitable by local Na+ spine spikes and global Ca2+- and Na+-spikes. To investigate the transition from local to global signaling without Na+ channel inactivation we performed simultaneous holographic two-photon uncaging in acute brain slices, along with whole-cell recording and dendritic Ca2+ imaging. Less than 10 coactive reciprocal spines were sufficient to generate diverse regional and global signals that also included local dendritic Ca2+- and Na+-spikes (D-spikes). Individual spines could sense the respective signal transitions as increments in Ca2+ entry. Dendritic integration was mostly linear until a few spines below global Na+-spike threshold, where often D-spikes set in. NMDARs strongly contributed to active integration, whereas morphological parameters barely mattered. In summary, thresholds for GC-mediated bulbar lateral inhibition are low.

Notch regulates wingless expression and is not required for reception of the paracrine wingless signal during wing margin neurogenesis in Drosophila

Development ◽  
1995 ◽  
Vol 121 (9) ◽  
pp. 2813-2824 ◽  
Author(s):  
E.J. Rulifson ◽  
S.S. Blair
Keyword(s):  
Lateral Inhibition ◽  
Sensory Cells ◽  
Temperature Sensitive ◽  
Wing Margin ◽  
Signal Loss ◽  
Subsequent Formation ◽  
Notch Protein ◽  
Sensory Bristles ◽  
Narrow Stripe

In the developing wing margin of Drosophila, wingless is normally expressed in a narrow stripe of cells adjacent to the proneural cells that form the sensory bristles of the margin. Previous work has shown that this wingless is required for the expression of the proneural achaete-scute complex genes and the subsequent formation of the sensory bristles along the margin; recently, it has been proposed that the proneural cells require the Notch protein to properly receive the wingless signal. We have used clonal analysis of a null allele of Notch to test this idea directly. We found that Notch was not required by prospective proneural margin cells for the expression of scute or the formation of sensory precursors, indicating Notch is not required for the reception of wingless signal. Loss of Notch from proneural cells produced cell-autonomous neurogenic phenotypes and precocious differentiation of sensory cells, as would be expected if Notch had a role in lateral inhibition within the proneural regions. However, loss of scute expression and of sensory precursors was observed if clones substantially included the normal region of wingless expression. These ‘anti-proneural’ phenotypes were associated with the loss of wingless expression; this loss may be partially or wholly responsible for the anti-proneural phenotype. Curiously, Notch- clones limited to the dorsal or ventral compartments could disrupt wingless expression and proneural development in the adjacent compartment. Analysis using the temperature-sensitive Notch allele indicated that the role of Notch in the regulation of wingless expression precedes the requirement for lateral inhibition in proneural cells. Furthermore, overexpression of wingless with a heat shock-wingless construct rescued the loss of sensory precursors associated with the early loss of Notch.

The Role of Viral Infection in Pest Control: A Mathematical Study

2007 ◽  
Vol 69 (8) ◽  
pp. 2649-2691 ◽  
Author(s):  
S. Ghosh ◽  
S. Bhattacharyya ◽  
D. K. Bhattacharya
Keyword(s):  
Viral Infection ◽  
Pest Control ◽  
Mathematical Study

Role of standard incidence in an eco-epidemiological system: A mathematical study

2006 ◽  
Vol 199 (3) ◽  
pp. 229-239 ◽  
Author(s):  
S. Pal ◽  
Kusumika Kundu ◽  
J. Chattopadhyay
Keyword(s):  
Mathematical Study ◽  
System A
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