Neocortical regions are organized into columns and layers. Connections between layers run mostly perpendicular to the surface suggesting a columnar functional organization. Some layers have long-range excitatory lateral connections suggesting interactions between columns. Similar patterns of connectivity exist in all regions but their exact role remain a mystery. In this paper, we propose a net...

The functional and anatomical rearrangements of cortical sensory maps accompanying changes in experience are not well understood. We examined in vivo and in vitro how the sensory map and underlying synaptic connectivity of the developing rat barrel cortex are altered when the sensory input to the cortex is partially deprived. In the nondeprived cortex, both the sensory responses and synaptic co...

We define incidence matrices to be zero-one matrices with no zero rows or columns. We are interested in counting incidence matrices with a given number of ones, irrespective of the number of rows or columns. A classification of incidence matrices is considered for which conditions of symmetry by transposition, having no repeated rows/columns, or identification by permutation of rows/columns are...

Screw and laser (SL) column by making screw threads and forming small holes using laser irradiation on the base metal and conventional beads coating (BC) columns were embedded into the shaft of canine femurs, and compared the implant fixation to the host bone. The interfacial strength in SL columns was almost equivalent as BC columns, and bone-column contact rate was higher than BC columns sign...

A bivariate population balance model (the base of LLECMOD program) for the dynamic simulation of liquid extraction columns is extended to simulate pulsed and sieve extraction columns. The model is programmed using visual digital FORTRAN and then integrated into the LLECMOD program. In addition pulsed and sieve tray columns, LLECMOD simulates stirred two types of agitated columns (RDC & Kühni). ...

We study how excitation and inhibition are distributed mesoscopically in small brain regions, by means of a computational model of coupled cortical columns described by neural mass models. Two cortical columns coupled bidirectionally through both excitatory and inhibitory connections can spontaneously organize in a regime in which one of the columns is purely excitatory and the other is purely ...

The columnar organization is a ubiquitous feature in the cerebral cortex. In this study, a neural network model simulating the cortical columns has been constructed. When fed with random pulse input with constant rate, a column generates synchronized oscillations, with a frequency varying from 3 to 43 Hz depending on parameter values. The behavior of the model under periodic stimulation was stu...