Ross Fiziol Zh Im I M Sechenova
May 2014
In normal rats and of those with parathyroprivous (hypocalcemic) tetany the comparative analysis of background activity (BA), tetanic and posttetanic increase and decrease of frequency of spinal cord (SC) motoneurons (MNs) responses under high-frequency (50, 100Hz) stimulation (HFS) of flexor (G) and extensor (P) hind-limb nerves have been conducted. The on-line selection and program analysis of the spikes was produced. On the 3-7 and 21-22 days of development of acute and chronic tetany, respectively, the significant tetanic and posttetanic changes of MNs activity without meaningful changes in BA was registered.
View Article and Find Full Text PDFRoss Fiziol Zh Im I M Sechenova
February 2014
Experimental and clinical data have shown that there is an increase in the necessity of pyrimidine nucleotides after peripheral nerve injury. The aim of the study was to estimate the neuroprotective efficacy of the Nucleo CMP preparation (Nucleo CMP. Ferrer Internacional) containing cytidine monophosphate and uridine triphosphate nucleotides after unilateral compression of the sciatic nerve of rats.
View Article and Find Full Text PDFChronic insufficiency of adrenal hormones is a pathology leading to brain dysfunction. In electrophysiological studies, by extracellular recording of spike activity of single hippocampal neurons (HN) caused by high-frequency stimulation of the entorhinal cortex (EC) in rats with unilateral removal of adrenal (adrenalectomy - AE), we analyzed mechanisms of adaptation of neural networks to chronic hormonal deprivation. The balance of excitatory and inhibitory responses, recorded in HN of intact rats was submitted to characteristic changes in dynamics of development of neurodegeneration: the dominating in norm inhibitory responses were decreased at all AE terms (from 42 % to 25 % by the 18th week).
View Article and Find Full Text PDFEffect of dexamethasone and desoxycorticosterone on the electrical activity of neurons in dorsal and ventral horn of spinal cord evoked by sciatic nerve stimulation were studied in adrenalectomized rats as well as effect of the same hormones on the background activity of single cells in the dorsal horn. The results demonstrated that both hormones (dexamethasone and desoxycorticosterone) provided enhancement of the amplitude of the field potentials recorded from the dorsal half of the spinal cord and facilitation of the background neuronal discharges of the single cells under investigation. It was stated that gluco- and mineralocorticoid hormones exerted different effects on the activity of ventral horn neurons of the spinal cord: dexamethasone++ potentiated and desoxycorticosterone depressed the amplitudes of the field potentials recorded from the region of motoneurons.
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