Biomedical subjects

Y B Shmukler

Publications and source records attributed to Y B Shmukler.

4 recordsLinked to original sources

PubMed1999

Action of serotonin antagonists on cytoplasmic calcium levels in early embryos of sea urchin Lytechinus pictus.

Possible interaction of the serotonergic system with intracellular calcium mechanisms was investigated using techniques of ratio imaging measurement of intracellular Ca2+ and confocal microscopy in cleaving embryos of sea urchin Lytechinus pictus. Some serotonin antagonists specifically increase free intracellular Ca2+ and evoke transient regression of the first cleavage furrow, suggesting possible linkage of serotonergic and calcium mechanisms in the regulation of cellular events during cleavage divisions. These effects were more pronounced in the experiments with hydrophilic 5-HT-antagonists, quarternary ammonium salts that do not penetrate the cell membrane. Thus, it appears that 5-HT-receptors which mediate these effects are localised on the cell membrane, whereas previously studied receptors mediating the cytostatic action of lipophilic 5-HT-antagonists are localised intracellularly.

Animals↗

PubMed1996

From oocyte to neuron: do neurotransmitters function in the same way throughout development?

1. Classical neurotransmitters (such as acetylcholine, biogenic amines, and GABA) are functionally active throughout ontogenesis. 2. Based on accumulated evidence, reviewed herein, we present an hypothetical scheme describing developmental changes in this functional activity, from the stage of maturing oocytes through neuronal differentiation. This scheme reflects not only the spatio-temporal sequence of these changes, but also the genesis of neurotransmitter functions, from "protosynapses" in oocytes and cleaving embryos to the development of functional neuronal synapses. 3. Thus, it appears that neurotransmitters participate in various forms of intra- and intercellular signalling throughout all stages of ontogenesis.

Animals↗

PubMed1993

Possibility of membrane reception of neurotransmitter in sea urchin early embryos.

1. Methiodide derivatives of serotonin blockers--inmecarb and KYur-14 which poorly penetrate the cells specifically affect the pattern of cleavage division in half-embryos of Paracentrotus lividus and Scaphechinus mirabilis. 2. Specific [3H]8-OH-DPAT binding under conditions strictly limiting penetration of the ligand into the cells of Strongylocentrotus intermedius was also shown (Kd approximately 3 x 10(-10) M for a site with the greatest affinity). 3. On the basis of the data obtained it is concluded that neurotransmitter-specific membrane receptors may be present in sea urchin embryos during cleavage divisions. The "protosynapse" hypothesis is proposed which suggests the existence of a specific structure responsible for early blastomere interaction involving transmitters.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1981

Possible role of "prenervous" neurotransmitters in cellular interactions of early embryogenesis: a hypothesis.

Evidence is presented in support of the working hypothesis that "prenervous" neurotransmitters directly participate in cell-cell interactions occurring during the first several cleavage divisions of sea urchin embryos, a function which may occur during the early development of higher animals as well. This intercellular signaling could be a link in the evolutionary progression from the use of these substances as intracellular regulators to their participation in cell-cell interactions occurring during synaptic transmission.

Animals↗