Search results for " inhibition"
showing 10 items of 435 documents
Long-term effects on motor cortical excitability induced by repeated muscle vibration during contraction in healthy subjects
2008
article i nfo Objective: The effects of a novel repeated muscle vibration intervention (rMV; 100 Hz, 90 min over 3 consecutive days) on corticomotor excitability were studied in healthy subjects. Methods: rMV was applied over the flexor carpi radialis (FCR) during voluntary contraction (experiment 1), during relaxation and during contraction without vibration (experiment 2). Focal transcranial magnetic stimulation (TMS) was applied before rMV and one hour, and one, two and three weeks after the last muscle vibration intervention. At each of these time points, we assessed the motor map area and volume in the FCR, extensor digitorum communis (EDC) and abductor digiti minimi (ADM). Short-inter…
Laminar and Columnar Structure of Sensory-Evoked Multineuronal Spike Sequences in Adult Rat Barrel Cortex In Vivo
2014
One of the most relevant questions regarding the function of the nervous system is how sensory information is represented in populations of cortical neurons. Despite its importance, the manner in which sensory-evoked activity propagates across neocortical layers and columns has yet not been fully characterized. In this study, we took advantage of the distinct organization of the rodent barrel cortex and recorded with multielectrode arrays simultaneously from up to 74 neurons localized in several functionally identified layers and columns of anesthetized adult Wistar rats in vivo. The flow of activity within neuronal populations was characterized by temporally precise spike sequences, which …
Inhibition of different GABA transporter systems is required to attenuate epileptiform activity in the CA3 region of the immature rat hippocampus
2014
GABA transporters (GATs) are an essential element of the GABAergic system, which regulate excitability in the central nervous system and are thus used as targets for anticonvulsive therapy. However, in the immature nervous system the functions of the GABAergic system and the expression profile of GATs are distinct from the adult situation, obscuring to predict how different GAT isoforms influence epileptiform activity. Therefore we analyzed the effects of subtype specific GAT inhibitors on repetitive epileptiform discharges using field potential and whole-cell patch-clamp recordings in the CA3 region of hippocampal slices of immature (postnatal days 4-7) rats. These experiments revealed tha…
The Polysialylated Form of the Neural Cell Adhesion Molecule (PSA-NCAM) Is Expressed in a Subpopulation of Mature Cortical Interneurons Characterized…
2010
Principal neurons in the adult cerebral cortex undergo synaptic, dendritic, and spine remodeling in response to different stimuli, and several reports have demonstrated that the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) participates in these plastic processes. However, there is only limited information on the expression of this molecule on interneurons and on its role in the structural plasticity of these cells. We have found that PSA-NCAM is expressed in mature interneurons widely distributed in all the extension of the cerebral cortex and have excluded the expression of this molecule in most principal cells. Although PSA-NCAM expression is generally considered a …
Nitric oxide inhibits electrically active units in the rat pineal gland.
1997
Extracellular multiple unit recordings were performed in isolated rat pineal glands to determine a possible effect of nitric oxide (NO) on the spontaneous electrical activity of pinealocytes. Spontaneously active cells forming clusters of 3-5 cells fell into two categories: more or less regularly firing clusters (REG, 64%) and irregularly discharging clusters with periodically repeated bursts (RHY, 36%). The NO-donor sodium nitroprusside (SNP) reduced the discharge rate of the great majority of REG clusters and of all the RHY clusters examined. Moreover, the burst activity of RHY clusters was abolished. These results could be completely reproduced by using another NO-donor, S-nitroso-N-acet…
Effects of acute and chronic maprotiline administration on inhibitory avoidance in male mice
2000
The effects of acute and chronic administration of maprotiline (5, 10 or 20 mg/kg, intraperitoneally) were assessed on inhibitory avoidance in male mice. Acute administration of maprotiline before training did not effect training phase latencies, but impaired performance (i.e. produced shorter latencies) in the test at doses of 5 and 20 mg/kg. When given after training, the drug did not modify test latencies at any of the doses used. Chronic administration for 21 days (interrupted 24 h before training) also shortened latencies in the test but not in training. An experiment on the acute effects of maprotiline on analgesia (determination of flinch and jump thresholds for increasing electric f…
Adolescent but not adult ethanol binge drinking modulates cocaine withdrawal symptoms in mice.
2016
Background Ethanol (EtOH) binge drinking is an increasingly common behavior among teenagers that induces long-lasting neurobehavioral alterations in adulthood. An early history of EtOH abuse during adolescence is highly correlated with cocaine addiction in adulthood. Abstinence of cocaine abuse can cause psychiatric symptoms, such as anxiety, psychosis, depression, and cognitive impairments. This study assessed the consequences of adolescent exposure to EtOH on the behavioral alterations promoted by cocaine withdrawal in adulthood. Methods We pretreated juvenile (34-47 days old) or adult (68-81 days old) mice with EtOH (1.25 g/kg) following a binge-drinking pattern. Then, after a three-week…
Disturbed social behavior and motivation in rats selectively bred for deficient sensorimotor gating
2007
Deficient prepulse inhibition (PPI) of startle reflects disturbed sensorimotor gating found in certain neuropsychiatric disorders. We here tested whether rats selectively bred for deficient PPI are deteriorated in behavioral paradigms used to model negative symptoms of schizophrenia. Rats with low PPI preferred standard rat-chow when having the choice between lever-pressing for reward-pellets or freely available rat-chow, suggesting reduced motivation. Additionally, these rats show deteriorated social behavior during interaction with a juvenile rat. Rats selectively bred for low PPI may therefore be used as a model to study the biological mechanisms and therapeutic strategies of negative sy…
Elimination of Ehrlich tumours by ATP-induced growth inhibition, glutathione depletion and X-rays
1995
ATP-induced tumour growth inhibition is accompanied by a selective decrease in the content of the tripeptide glutathione (GSH) within the cancer cells in vivo. Depletion of cellular GSH sensitizes tumours to chemotherapy and radiation, but the usefulness of this depletion depends on whether the levels of GSH can be reduced in the tumour relative to normal tissues. We report here that administration of ATP in combination with diethylmaleate and X-rays leads to complete regression of 95% of Ehrlich ascites tumours in mice. This shows that an aggressive tumour can be eliminated by using a therapy based on modulation of GSH levels in cancer cells.
Alterations in the spontaneous activity of cells in the guinea pig pineal gland and visual system produced by pineal indoles
1982
The indoles serotonin (SER), melatonin (MEL), 5-methoxytryptophol (5-MTL) and 5-hydroxytryptophol (5-HTL) were administered during daytime microelectrophoretically to 240 cells in the pineal gland of the guniea-pig. The action of SER and 5-HTL was predominantly depressant on the electrical activity, MEL and 5-MTL caused an excitation in most of the units. Although MEL and 5-MTL caused fairly similar reactions on average, they appear to act on different cells. The effects of microelectrophoretically applied MEL and 5-MTL on the spontaneous or evoked activity in the visual system (retinal ganglion cells, optic tract, lateral lateral geniculate body, superior colliculus) of the guinea-pig were…