No abstract

The impact of tonic conductance upon population activity was investigated. An extra tonic transmembrane current through GABA-activated extrasynaptic GABA -receptors was found to control stationary asynchronous firing both quantitatively and qualitatively. Quantitative regulation consisted in alterating a current level of stationary population activity while qualitative regulation manifested itself in appearance of resilient asynchronous spiking in case GABA reversal potential exceeded a certain threshold. The study was based on a modified rate model after Wilson and Cowan and backed up with a computer simulation of an explicit network model.

The present paper deals with the calibration method of interferometers with antennas having a small effective area, on the quasinoise signals of GLONASS and GPS navigation satellites. Algorithms for calculation of antenna coordinates and instrumental delay from the analysis of correlation interferometer response to signals of satellites in the near field of the instrument were reviewed. The method was tested in VLBI experiments on interferometers with medium and large baselines that included radio telescopes of NIRFI and VIRAC. The values of the antenna coordinates and instrumental delay with an error within the limits of one discrete were obtained. The sources of measurement errors and ways to improve the accuracy of results were analysed.

Dynamics of a homogeneous neural population interacting with active extracellular medium were considered. The corresponding mathematical model was tuned specifically to describe the behavior of interneurons with tonic GABA conductance under the action of non-stationary ambient GABA. The feedback provided by the GABA mediated transmembrane current enriched the repertoire of population activity by enabling the oscillatory behavior. This behavior appeared in the form of relaxation oscillations which can be considered as a specific type of brainwaves.