[Temporal specificity in stimulus action during the formation of associative ultrastructural restructurings in...

By a method of electronic microscopy morphological characteristics were studied of various components of neurones synapses in the sensorimotor cortical zone of rats at different variants of combined and noncombined repeated microiontophoretic presentation of glutamate and acetylcholine. Significant dependence was found of the character and rate of reorganizations of postsynaptic thickness (PSTh), width of synaptic cleft and length of synapses active zone on temporal relations in transmitters action: significant changes of PSTh thickness appeared only in conditions of combined presentations of stimuli (neurotransmitters); maximum thickening of PsTh was caused by the combined action of glutamate and acetylcholine with 3 s delay of the latter. The hypothesis is suggested that temporal specificity during integration of associated signals action to neurones is determined by kinetics of interacting biochemical regulating mechanisms.