[Regulation of the efficacy of adrenergic synaptic transmission by autoadrenoreceptors in rat brain slices].
A hypothesis of the role of autoadrenoreceptors in the processes of synaptic depression, facilitation, PSP amplitude stabilization and amplitude increase with the stimulation frequency growth is described by means of a mathematical model. Synaptic depression is realized by activation of alpha-autoadrenoreceptors, synaptic facilitation--by beta-autoadrenoreceptors activation. A "stable secretion zone" is formed between the autoadrenoreceptor activation curves at which noradrenaline secretion is stabilized. Experimental studies of H3-NA secretion from rats cerebral cortex slices showed that autoadrenoreceptors really form a stable secretion zone. The presence of stable secretion zone provides for self-facilitation and stabilization of H3-NA secretion elicited by 5-fold consecutive K+-depolarizations of slices with time interval 30 min. The absence of the stable secretion zone leads to destabilization of H3-NA secretion. With an increase of the stimulation intensity the curves of autoadrenoreceptors activity and stable secretion zone shift toward high noradrenaline concentrations.
D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D009638:Norepinephrine / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011941:Receptors, Adrenergic / Q000502:physiology*; D011942:Receptors, Adrenergic, alpha / Q000502:physiology; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D012621:Seasons; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission
D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D011188:Potassium; D009638:Norepinephrine
Reguliatsiia éffektivnosti adrenergicheskoĭ sinapticheskoĭ peredachi autoretseptorami v srezakh mozga krys.