Biomedical subjects

Nir Kalisman

Publications and source records attributed to Nir Kalisman.

3 recordsLinked to original sources

PubMed2005

MESHI: a new library of Java classes for molecular modeling.

UNLABELLED: Adapting a modular and object-oriented approach in the design of molecular modeling packages may reduce the software development barrier between ideas and their programed applications. Towards this goal we developed MESHI, a new, strictly object-oriented, molecular modeling suite written in Java. MESHI provides a comprehensive library of extendable classes for all the essential components of molecular modeling: molecular and geometry elements, energy functions and optimization methods. AVAILABILITY: MESHI and its related documentation are freely available at http://www.cs.bgu.ac.il/~meshi; the MESHI API is available at http://www.cs.bgu.ac.il/~meshi/API CONTACT: keasar@cs.bgu.ac.il SUPPLEMENTARY INFORMATION: The Supplementary information includes (1) a detailed description of several key packages and classes, and (2) a brief presentation of results achieved by using the MESHI application--Beautify--in the CASP6 experiment.

Computer Simulation↗

PubMed2005

The neocortical microcircuit as a tabula rasa.

The neocortex has a high capacity for plasticity. To understand the full scope of this capacity, it is essential to know how neurons choose particular partners to form synaptic connections. By using multineuron whole-cell recordings and confocal microscopy we found that axons of layer V neocortical pyramidal neurons do not preferentially project toward the dendrites of particular neighboring pyramidal neurons; instead, axons promiscuously touch all neighboring dendrites without any bias. Functional synaptic coupling of a small fraction of these neurons is, however, correlated with the existence of synaptic boutons at existing touch sites. These data provide the first direct experimental evidence for a tabula rasa-like structural matrix between neocortical pyramidal neurons and suggests that pre- and postsynaptic interactions shape the conversion between touches and synapses to form specific functional microcircuits. These data also indicate that the local neocortical microcircuit has the potential to be differently rewired without the need for remodeling axonal or dendritic arbors.

Animals↗

PubMed2003

Deriving physical connectivity from neuronal morphology.

A model is presented that allows prediction of the probability for the formation of appositions between the axons and dendrites of any two neurons based only on their morphological statistics and relative separation. Statistics of axonal and dendritic morphologies of single neurons are obtained from 3D reconstructions of biocytin-filled cells, and a statistical representation of the same cell type is obtained by averaging across neurons according to the model. A simple mathematical formulation is applied to the axonal and dendritic statistical representations to yield the probability for close appositions. The model is validated by a mathematical proof and by comparison of predicted appositions made by layer 5 pyramidal neurons in the rat somatosensory cortex with real anatomical data. The model could be useful for studying microcircuit connectivity and for designing artificial neural networks.

Animals↗