[Desmosome-like contacts of Mauthner neurons as targets of scorpion venom].
Desmosome-like contacts (DLC) in afferent chemical synapses of the Mauthner cells (MC) were investigated after application of low and high molecular mass peptide fractions 6 and 9, correspondingly, from the Central Asiatic black scorpion Orthochirus scrobiculosus. Besides, the DLC were examined in condition of a training induced morpho-functional stability of the MC (adaptation) mediated by transformation of actin monomers into polymers. In addition, the structure of DLC was studied after cytochalasin application which disrupts F-actin. Fraction 6 was shown to increase the length of DLC and osmiophily of fibrous material. Similar changes in DLC were caused by adaptation. Fraction 9 decreased the osmiophily of the fibrous material, made DLC asymmetric, but did not influence their length. Similar changes in DLC were seen also after cytochalasin D application. Taking into account our previous data on the role of F-actin in the MC functioning, which were obtained following specific pharmacological treatments, the similarity of ultrastructural changes in DLC after both adaptation and fraction 6 application, on the one hand, and after both cytochalasin D and fraction 9 application, on the other one, enabled us to suggest that these fractions may contain peptides able to exert influence of the actin cytoskeleton.
Mikheeva
I B
IB
Department of Cytotechnology, Pushchino State University.
Tiras
N R
NR
Moshkov
D A
DA
Pashkov
V I
VI
Grishin
E V
EV
D000818:Animals; D003896:Desmosomes / Q000187:drug effects / Q000648:ultrastructure*; D006054:Goldfish; D066298:In Vitro Techniques; D008526:Medulla Oblongata / Q000648:ultrastructure*; D008854:Microscopy, Electron; D009475:Neurons, Afferent / Q000187:drug effects / Q000648:ultrastructure*; D012604:Scorpion Venoms / Q000494:pharmacology*
D012604:Scorpion Venoms