Search results for "clam"
showing 10 items of 454 documents
Estimation of ambient GABA levels in layer I of the mouse neonatal cortex in brain slices
2010
GABAergic synapses on Cajal–Retzius neurons in layer I of the murine neocortex experience GABAB receptor (GABABR)-mediated tonic inhibition. Extracellular GABA concentration ([GABA]o) that determines the strength of GABABR-mediated inhibition is controlled by GABA transporters (GATs). In this study, we hypothesized that the strength ofpresynaptic GABABR activation reflects [GABA]o in the vicinity of synaptic contacts. Slices obtained from two age groups were used, namely postnatal days (P)2–3 and P5–7. GABAergic postsynaptic currents (IPSCs) were recorded using the whole-cell patch-clamp technique. Minimal electrical stimulation in layer I was applied to elicit evoked IPSCs (eIPSCs) using a…
Resonance properties of different neuronal populations in the immature mouse neocortex
2012
In vivo recordings in the immature neocortex revealed spontaneous and sensory-driven oscillatory activity from delta (0.5-4 Hz) to gamma (30-100 Hz) frequencies. In order to investigate whether the resonance properties of distinct neuronal populations in the immature neocortex contribute to these network oscillations, we performed whole-cell patch-clamp recordings from visually identified neurons in tangential and coronal neocortical slices from postnatal day (P)0-P7 C57Bl/6 mice. Subthreshold resonance was analysed by sinusoidal current injection of varying frequency. All Cajal-Retzius cells showed subthreshold resonance, with an average frequency of 2.6 ± 0.1 Hz (n = 60), which was massiv…
Model predictions of the ionic mechanisms underlying the beating and bursting pacemaker characteristics of molluscan neurons
1976
The general properties of the excitable membrane on molluscan pacemaker neurons can be described on the basis of a fair amount of experimental evidence available in the literature. The neuronal membrane exhibits under voltage clamp an initial inward current carried by both Na+ and Ca2+ ions, the time- and voltage-dependent characteristics of which are similar to that of other excitable structures. The conductance mechanism for the two ion species and the transport kinetics appear to be closely similar. The time course and amplitude of the delayed outward current carried by K+ ions shows a marked dependence on the membrane potential. Characteristic for the molluscan neurons is the existence …
Allosterically potentiating ligands of nicotinic receptors as a treatment strategy for Alzheimer's disease.
2000
Abstract One of the most prominent cholinergic deficit in Alzheimer’s disease (AD) is the reduced number of nicotinic acetylcholine receptors (nAChR) in the hippocampus and cortex of AD patients, as compared to age-matched controls. This deficit results in reduced nicotinic cholinergic excitation which may not only impair postsynaptic depolarization but also presynaptic neurotransmitter release and Ca 2+ -dependent intracellular signaling, including transcriptional activity. Presently, the most common approach to correct the nicotinic cholinergic deficit in AD is the application of cholinesterase inhibitors. Due to the resulting increase in synaptic acetylcholine levels, both in concentrati…
Sensitivity of neuronal nicotinic acetylcholine receptors to the opiate antagonists naltrexone and naloxone: receptor blockade and up-regulation
2003
In HEK293 cells stably expressing alpha4beta2 nAChRs, naltrexone, but not naloxone, blocked alpha4beta2 nAChRs via an open-channel blocking mechanism. In primary hippocampal cultures, naltrexone inhibited alpha7 nAChRs up-regulated by nicotine, and in organotypic hippocampal cultures naltrexone caused a time-dependent up-regulation of functional alpha7 nAChRs that was detected after removal of the drug. These results indicate that naltrexone could be used as a smoking cessation aid.
Priekšlaicīgu dzemdību izraisītu grūtniecības komplikāciju izvērtējums.
2017
Cēlonis: Grūtniecības komplikācijas ir galvenie iemesli mātes un augļa mortality.Pregnancy komplikāciju mainās dažādās populāciju, BMI un vecuma grupā. Saskaņā ar Global Health observatoriju, kuri katru dienu 2015. gadā, aptuveni 830 sievietes nomira dēļ komplikācijas grūtniecības un bērna piedzimšanas. Tāpēc ir ļoti svarīgi, lai analizētu grūtniecības komplikācijas gan priekšlaicīgas dzemdības un normālu termiņa piegāde (vadības grupa). Mērķi: Pētījuma mērķis ir analizēt dažas grūtniecības komplikācijas un salīdzināt tos no priekšlaicīgas dzemdības un kontroles grupu, un salīdzināt tos ar vecuma grupu un ĶMI grupu. Materiāli un metodes: Pētījums modelis ietver datus, kas savākti no Rig…
Perforated Patch-clamp Recording of Mouse Olfactory Sensory Neurons in Intact Neuroepithelium: Functional Analysis of Neurons Expressing an Identifie…
2015
Analyzing the physiological responses of olfactory sensory neurons (OSN) when stimulated with specific ligands is critical to understand the basis of olfactory-driven behaviors and their modulation. These coding properties depend heavily on the initial interaction between odor molecules and the olfactory receptor (OR) expressed in the OSNs. The identity, specificity and ligand spectrum of the expressed OR are critical. The probability to find the ligand of the OR expressed in an OSN chosen randomly within the epithelium is very low. To address this challenge, this protocol uses genetically tagged mice expressing the fluorescent protein GFP under the control of the promoter of defined ORs. O…
Postnatal odorant exposure induces peripheral olfactory plasticity at the cellular level
2014
Mammalian olfactory sensory neurons (OSNs) form the primary elements of the olfactory system. Inserted in the olfactory mucosa lining of the nasal cavity, they are exposed to the environment and their lifespan is brief. Several reports say that OSNs are regularly regenerated during the entire life and that odorant environment affects the olfactory epithelium. However, little is known about the impact of the odorant environment on OSNs at the cellular level and more precisely in the context of early postnatal olfactory exposure. Here we exposed MOR23-green fluorescent protein (GFP) and M71-GFP mice to lyral or acetophenone, ligands for MOR23 or M71, respectively. Daily postnatal exposure to …
Plerixafor is effective and safe for stem cell mobilization in heavily pretreated germ cell tumor patients.
2010
Up to 10% of germ cell tumor patients require salvage high-dose chemotherapy with stem cell support, achieving cure rates in the range of 10-60%. Stem cell mobilization may be difficult in these patients because of multiple lines of treatment known to seriously hamper stem cell recovery. Plerixafor significantly enhances the success of the CD34+ cell harvest, even in cases where prior mobilization attempts have failed. Six germ cell tumor patients provided informed consent and were included in the compassionate use program. All patients were heavily pretreated, with a median of 3.5 prior lines of therapy. All failed prior mobilization with G-CSF in combination with chemotherapy. Five patien…
Fusarium wilt of cyclamen : early detection and biocontrol
2016
Fusarium wilt of cyclamen is one of the most damaging diseases of cyclamen. The causal agent, Fusarium oxysporum f. sp. cyclaminis, is a soil-borne fungus. Losses can reach more than 50 % of the production. Several methods of control are available, but none of them offer an efficient and environmentally friendly solution. In this context, a project was developed in collaboration with the French institute of horticulture, Astredhor, which represents the producers, the INRA of Dijon, for its expertise on F. oxysporum and the company Agrene for its expertise in biological control. The project has two goals: i) design a molecular marker specific of Fusarium oxysporum f. sp. cyclaminis allowing …