Dimebon and tacrine inhibit neurotoxic action of beta-amyloid in culture and block L-type Ca(2+) channels.

Dimebon, a Russian-made drug, inhibited toxic effects of beta -amyloid on cultured neurons. Excessive accumulation of beta-amyloid in the brain is characteristic of Alzheimer dementias. Antialzheimer preparations tacrine and dimebon improve survival of cerebellar granule cells during long-term incubation with Abeta25-35, the neurotoxic fragment of beta-amyloid.

Elementary receptor currents elicited by a single pheromone molecule exhibit quantal composition.

Responses to single pheromone molecules, elementary receptor currents (ERC), recorded from antennal olfactory receptor neurones of the moth Bombyx mori were studied in situ, at the opened sensilla, using the voltage-clamp technique in transepithelial recordings. The amplitude parameters of the ERCs eliciting one action potential in the bombykol and bombykal receptor neurones were analysed. The ERC amplitude varied largely within a range of 0.

Guanosine 3',5'-cyclic monophosphate reduces the response of the Moth's olfactory receptor neuron to pheromone.

The effects of the membrane-permeable dibutyryl guanosine 3', 5'-cyclic monophosphate (db-cGMP) on the bombykol-elicited receptor current and nerve impulse activity were studied using the open sensillum recording technique. db-cGMP was applied to the outer dendritic membrane of the olfactory receptor neuron of the moth Bombyx mori. db-cGMP reduced the amplitude of the overall receptor current activated by a pulse of strong pheromone stimuli as well as diminished the nerve impulse frequency elicited by continuously applied weak pheromone stimuli.

Identification of PLC beta and PKC in pheromone receptor neurons of Antheraea polyphemus.

Two proteins of the IP3 transduction pathway were identified by Western blots in homogenates of isolated pheromone-sensitive sensilla of the silkmoth Antheraea polyphemus. A 110 kDa protein was recognized by an antiserum raised against the Drosophila phospholipase C beta (PLC beta p121) and a 80kDa protein was labelled by an antiserum against a synthetic peptide of a conserved region of protein kinase C (PKC). Incubation of homogenized sensory hairs with the main sex pheromone component, (E,Z) 6-11 hexadecadienyl acetate, resulted in a 6-fold increase in the activity of PKC compared to controls without pheromone.

G-protein activation, identification and immunolocalization in pheromone-sensitive sensilla trichodea of moths.

Electrophysiological in situ recordings from pheromone-sensitive sensilla trichodea of Bombyx mori males with a recording pipette which contained G-protein-activating fluoride, showed receptor cell activity similar to that evoked by pheromone stimulation. This suggests that G-proteins might be physiologically active in olfactory sensilla of insects in situ. Biochemical experiments using specific antibodies revealed the presence of G-protein, belonging to the Gq family, in antennal preparations.