Andrej V. Popov

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In the cricket ear, sound acts on the external surface of the tympanum and also reaches the inner surface after travelling in at least three pathways in the tracheal system. We have determined the transmission gain of the three internal sound pathways; that is, the change of amplitude and phase angle from the entrances of the tracheal system to the inner(More)
Comparative study of phonotactic reactions of females of 5 species of crickets to the calling song (CS) of conspecific males and different sound models in Y-maze experiments showed: 1. InGryllodinus kerkennensis the essential property of the signal is the continuity of the song (Fig 3). 2. InGryllus campestris andG. bimaculatus pulse rate and chirp duration(More)
1. The large segmental auditory neuron (LSAN) was identified both morphologically and physiologically in experiments with extracellular recording of spike potentials by electrodes filled with 2–3 M CoCl2. 2. The LSAN connects left and right auditory neuropiles of the prothoracic ganglion and has no branches outside them (Fig. 3). Soma-ipsilateral(More)
Two ventral-cord neurons in the auditory system ofGryllus bimaculatus were studied electrophysiologically by stimulation with pulses of sound at a single frequency (sine-wave pulses), stridulatory songs, and artificial sounds constructed to imitate the conspecific songs. The sine-wave pulses were varied in frequency, sound intensity, duration, and(More)
Sound radiation was studied in males of Tympanistalna gastrica St»l during a spontaneous song with the characteristics of the conspecific calling song, which was elicited as an after effect of brain stimulation. The song contains two different kinds of sound pulses: 1) loud clicks and 2) soft pulses, presenting different spectra. The timbals, abdomen,(More)
In behavioral experiments with a Y labyrinth it was shown that phonotaxis in the female crickets in respect to the calling signals (CS) of the males depends on the spectrum of the signal. The necessary and sufficient condition for development of normal phonotaxis is the preservation of the first, low-frequency (LF) component of the spectrum (5 kHz). Signals(More)
Analytical theory and numerical approaches to the simulation and optimal design of multilayer mirrors and optical Bragg waveguides are developed. Optimal refractive index profiles in planar and cylindrical geometry are found. Reduction of the full set of Maxwell’s equations to a scalar boundary value problem in the lowcontrast approximation is discussed. An(More)
After chronic melatonin administration (1 mg/kg, 14 days) the content of cytochrome P-450 and activity of NADPH: cytochrome c-reductase in rat microsomes were increased. Pinealectomized rats had opposite directed shifts in microsomal oxidation. In these animals activated effect of melatonin was absent.
1. A high-frequency auditory neurone (HF1AN) was identified morphologically and physiologically in the prothoracic ganglion of the cricket,Gryllus bimaculatus DeGeer. 2. The main inputs of the HF1AN are from the lateral and medial parts of the auditory neuropile ipsilateral to the axon and to a lesser extent, the medial part of the contralateral auditory(More)
In male rats sound conditioned reflex with water reinforcement was gradually (within 14-16 daily training sessions) was replaced by a conditioned reflex to time. After the bilateral lesions of the suprachiasmatic nuclei of hypothalamus, the necessary level of timing performance was reached sooner than in the animals with a partial destruction of the nuclei.