Search results for "POTENTIALS"
showing 10 items of 1072 documents
Proton conductance of human transient receptor potential-vanilloid type-1 expressed in oocytes of Xenopus laevis and in Chinese hamster ovary cells.
2004
Transient receptor potential-vanilloid type-1 (TRPV1) is a ligand-gated cation channel with preference for divalent cations, especially Ca(2+) (sequence of conductances: Ca(2+)Mg(2+)Na(+) approximately/= K(+) approximately/= Cs(+)). In the present study, the two-electrode voltage-clamp technique was used on oocytes of Xenopus laevis expressing TRPV1 to evaluate whether human TRPV1 also conducts protons. In medium devoid of K(+), Na(+), Mg(2+), and Ca(2+), capsaicin 1 microM induced a significant inward current (62% of the current in physiological medium). The effects of capsaicin were abolished in the presence of capsazepine 3 microM. The capsaicin-induced currents in medium devoid of Na(+)…
Oxygen and glucose deprivation induces major dysfunction in the somatosensory cortex of the newborn rat
2005
The mechanisms and functional consequences of ischemia-induced injury during perinatal development are poorly understood. Subplate neurons (SPn) play a central role in early cortical development and a pathophysiological impairment of these neurons may have long-term detrimental effects on cortical function. The acute and long-term consequences of combined oxygen and glucose deprivation (OGD) were investigated in SPn and compared with OGD-induced dysfunction of immature layer V pyramidal cortical neurons (PCn) in somatosensory cortical slices from postnatal day (P)0-4 rats. OGD for 50 min followed by a 10-24-h period of normal oxygenation and glucose supply in vitro or in culture led to pron…
Antipsychotic drugs antagonize human serotonin type 3 receptor currents in a noncompetitive manner
2004
The serotonin type 3 (5-HT(3)) receptor is the only ligand-gated ion channel receptor for serotonin (5-HT). 5-HT(3) receptors play an important role in modulating the inhibitory action of dopamine in mesocorticolimbic brain regions. Neuroleptic drugs are commonly thought to exert their psychopharmacological action mainly through dopamine and serotonin type 2 (5-HT(2)) receptors. Except for clozapine, a direct pharmacological interaction of neuroleptics with 5-HT(3) receptors has not yet been described. Using the concentration-clamp technique, we investigated the effects of flupentixol, various phenothiazines, haloperidol, clozapine and risperidone on Na(+)-inward currents through 5-HT(3) re…
Enhanced inhibitory control during re-engagement processing in badminton athletes : An event-related potential study
2019
Highlights • Reaction time and event-related potentials of inhibitory control were compared in badminton experts and nonathletes. • Badminton experts showed enhanced inhibitory control and more efficient neural mechanisms. • Badminton experts performed better inhibitory control processing in re-engagement. • The re-engagement processing better demonstrated altered brain activity in badminton experts.
Evidence for a respiration-modulated cholinergic action on the activity of medullary respiration-related neurons in the rabbit. An iontophoretic stud…
1989
Effects of the iontophoretically administered cholinergic agonists acetylcholine, bethanechol and DMPP on the activity of medullary respiration-related neurons were examined in urethane-anaesthetized rabbits. Inhibitory effects prevailed over excitatory effects. Analysis of cholinergic effects by cycle-triggered averaging revealed three major types of neuronal responses: (i) constant alterations of spike-density throughout the whole period of activity ("constant effects"), (ii) effects increasing during the progression of the burst of discharge or effects restricted to a particular fraction of the burst ("phasic effects") and (iii) effects which were characterized by an excitation during on…
Independent component analysis on the mismatch negativity in an uninterrupted sound paradigm.
2008
We compared the efficiency of the independent component analysis (ICA) decomposition procedure against the difference wave (DW) and optimal digital filtering (ODF) procedures in the analysis of the mismatch negativity (MMN). The comparison was made in a group of 54 children aged 8-16 years. The MMN was elicited in a passive oddball protocol presenting uninterrupted auditory stimulation consisting of two frequent alternating tones (600 and 800 Hz) of 100 ms duration each. Infrequently, one of the 600 Hz tones was shortened to 50 or 30 ms. The event related potentials (ERPs) were decomposed into the MMN-like and non-MMN-like independent components (ICs) through the FastICA algorithm. The ICA …
Neural conservation in skull base surgery
2002
Surgical treatment of lesions of the skull base carries significant risk to the functioning of the cerebral hemispheres, brainstem, and cranial nerves. This risk is due to both (1) problems associated with maintaining an adequate blood flow while exposing and removing the tumor and (2) direct or indirect trauma to the brain, perineural tissues, and cranial nerves. These risks may be reduced if information about possible implications of surgical maneuvers on the cerebral blood flow and on the function of the patient’s CNS and cranial nerves is available and can be monitored during surgery of the skull base. The use of EMG neuromonitoring for the facial nerve and of brainstem evoked response …
Secretory effect of azodisalicylate (azodisal sodium) on the short circuited mucosa of the rat ileum in vitro.
1988
Azodisalicylate (ADS) is one of the newly developed substitutes of sulphasalazine consisting of two molecules of 5-amino-salicylic acid. Azodisalicylate caused diarrhoea in some patients, apparently caused by an antiabsorptive secretagogue action of this compound. The mechanism of this was studied in the short circuited isolated mucosa of the rat ileum. Mucosal addition of ADS increased the potential difference (PD) and short circuit current (Isc) at a concentration of 1.3.10(-4) mol/l (4 mg/dl) with maximal effects at 1.3.10(-3) mol/l (40 mg/dl). Epithelial resistance was only slightly decreased at the higher concentrations of 40 and 100 mg/dl. Serosal ADS had no effect on electrical param…
Model-specific effects of bumetanide on epileptiform activity in the in-vitro intact hippocampus of the newborn mouse.
2007
The immature brain has a higher susceptibility to develop seizures, which often respond poorly to classical pharmacological treatment. It has been recently suggested that bumetanide, which blocks Na(+)-dependent K(+)-Cl(-)-cotransporter isoform 1 (NKCC1) and thus attenuates depolarizing GABAergic responses, could soothe epileptiform activity in immature nervous systems. To evaluate whether bumetanide consistently attenuates epileptiform activity, we investigated the effect of 10 microM bumetanide in five different in-vitro epilepsy models using field potential recordings in the CA3 region of intact mouse hippocampal preparations at postnatal day 4-7. Bumetanide reduced amplitude and frequen…
Brain event-related potentials to phoneme contrasts and their correlation to reading skills in school-age children
2017
Development of reading skills has been shown to be tightly linked to phonological processing skills and to some extent to speech perception abilities. Although speech perception is also known to play a role in reading development, it is not clear which processes underlie this connection. Using event-related potentials (ERPs) we investigated the speech processing mechanisms for common and uncommon sound contrasts (/ba/-/da/-/ga/ and /ata/-/at: a/) with respect to the native language of school-age children in Finland and the US. In addition, a comprehensive behavioral test battery of reading and phonological processing was administered. ERPs revealed that the children could discriminate betw…