[Role of adenosine A(2A) receptors of preoptical area in realization of somnogenic effect of protein 70 kDa in pigeons].

In representatives of class of birds (pigeons Columba livia) using electrophysiological methods for the first time there was performed analysis of effects of microinjections into the hypothalamic ventrolateral preoptical area (VLPA) of antagonists of the adenosine A(2A) type receptors on the sleep-wale cycle under natural conditions and on realization of somnogenic effect of Heat shock protein 70 kDa (Hsp70). The following has been established: 1) microinjections of adenosine A(2A) receptors antagonist (8-(3-Chlorostyryl) caffeine (ChC)) into VLPA at the beginning of inactive phase of the 24-h period dose-dependently increase wakefulness and suppress sleep; 2) microinjections of Hsp70 into VLPA produce somnogenic effect manifested as an increase of the total time of slow sleep (SS) and enhancement of mechanisms of initiation and maintenance of SS; 3) block of adenosine A(2A) receptors by ChC suppresses the Hsp70-induced SS. The obtained data indicate participation of adenosine A(2A) receptors located in VLPA in modulation of the sleep-wake cycle under natural conditions and in realization of somnogenic effect of Hsp70 in pigeons. A hypothesis is put forward that the somnogenic action of Hsp70 is mediated by modulating effect of this chaperone on function of adenosine proteins-receptors.