title: Substances in subthreshold concentrations under stress conditions can act as conditioned stimuli and trigger defense reactions.
abstract: The capacity of living systems to perceive low-intensity stimuli sometimes inducing protective reactions is still little studied. Incubation of neurons under conditions increasing the content of cAMP and Ca(2+) increases the amplitude of their responses to lidocaine (10(-3) M). After cell preconditioning with low concentrations of lidocaine (10(-15) M) under these conditions, the protective effects of "ineffective" concentrations were detected, because the response amplitude did not decrease. It was hypothesized that the basic amplitude responses retrieved by lidocaine in a concentration of 10(-3) M are memory traces about the effects of this compound in subthreshold concentrations.
authors.affiliation: Engineering and Design Institute of Computer Science, Siberian Division of Russian Academy of Sciences, Russia. zap@kti.nsc.ru
authors.forename: T A
authors.initials: TA
authors.lastname: Zapara
authors.forename: A L
authors.initials: AL
authors.lastname: Proskura
authors.forename: A S
authors.initials: AS
authors.lastname: Ratushnyak
authors.forename: M B
authors.initials: MB
authors.lastname: Shtark
authors.forename: O I
authors.initials: OI
authors.lastname: Epstein
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D003216:Conditioning, Operant; D000242:Cyclic AMP / Q000378:metabolism; D008012:Lidocaine / Q000008:administration & dosage*; D008195:Lymnaea / Q000502:physiology*
chemical_list: D008012:Lidocaine; D000242:Cyclic AMP; D002118:Calcium