Search results for "Patch-Clamp Techniques"
showing 10 items of 79 documents
Intracellular Na+ concentration influences short-term plasticity of glutamate transporter-mediated currents in neocortical astrocytes.
2012
Fast synaptic transmission requires a rapid clearance of the released neurotransmitter from the extracellular space. Glial glutamate transporters (excitatory amino acid transporters, EAATs) strongly contribute to glutamate removal. In this work, we investigated the paired-pulse plasticity of synaptically activated, glutamate transporter-mediated currents (STCs) in cortical layer 2/3 astrocytes. STCs were elicited by local electrical stimulation in layer 4 in the presence of ionotropic glutamate (AMPA and NMDA), GABAA, and GABAB receptor antagonists. In experiments with low [Na+]i (5 mM) intrapipette solution, STCs elicited by paired-pulse stimulation demonstrated paired-pulse facilitation (…
Temporally precise control of single-neuron spiking by juxtacellular nanostimulation
2017
Temporal patterns of action potentials influence a variety of activity-dependent intra- and intercellular processes and play an important role in theories of neural coding. Elucidating the mechanisms underlying these phenomena requires imposing spike trains with precisely defined patterns, but this has been challenging due to the limitations of existing stimulation techniques. Here we present a new nanostimulation method providing control over the action potential output of individual cortical neurons. Spikes are elicited through the juxtacellular application of short-duration fluctuating currents (“kurzpulses”), allowing for the sub-millisecond precise and reproducible induction of arbitr…
Plasticity-Related Gene 1 Affects Mouse Barrel Cortex Function via Strengthening of Glutamatergic Thalamocortical Transmission
2016
Plasticity-related gene-1 (PRG-1) is a brain-specific protein that modulates glutamatergic synaptic transmission. Here we investigated the functional role of PRG-1 in adolescent and adult mouse barrel cortex both in vitro and in vivo. Compared with wild-type (WT) animals, PRG-1-deficient (KO) mice showed specific behavioral deficits in tests assessing sensorimotor integration and whisker-based sensory discrimination as shown in the beam balance/walking test and sandpaper tactile discrimination test, respectively. At P25-31, spontaneous network activity in the barrel cortex in vivo was higher in KO mice compared with WT littermates, but not at P16-19. At P16-19, sensory evoked cortical respo…
Inhibition of rapid heat responses in nociceptive primary sensory neurons of rats by vanilloid receptor antagonists.
1999
Recent studies demonstrated that heat-sensitive nociceptive primary sensory neurons respond to the vanilloid receptor (VR) agonist capsaicin, and the first cloned VR is a heat-sensitive ion channel. Therefore we studied to what extent heat-evoked currents in nociceptive dorsal root ganglion (DRG) neurons can be attributed to the activation of native vanilloid receptors. Heat-evoked currents were investigated in 89 neurons acutely dissociated from adult rat DRGs as models for their own terminals using the whole cell patch-clamp technique. Locally applied heated extracellular solution (effective temperature ∼53°C) rapidly activated reversible and reproducible inward currents in 80% (62/80) o…
Cell type-specific circuits of cortical layer IV spiny neurons
2003
Sensory signal processing in cortical layer IV involves two major morphological classes of excitatory neurons: spiny stellate and pyramidal cells. It is essentially unknown how these two cell types are integrated into intracortical networks and whether they play different roles in cortical signal processing. We mapped their cell-specific intracortical afferents in rat somatosensory cortex through a combination of whole-cell patch-clamp recordings and caged glutamate photolysis. Spiny stellate cells received monosynaptic excitation and inhibition originating almost exclusively from neurons located within the same barrel. Pyramidal cells, by contrast, displayed additional excitatory inputs fr…
Single mechano-gated channels activated by mechanical deformation of acutely isolated cardiac fibroblasts from rats
2010
Aim Mechanosensitive conductances were reported in cardiac fibroblasts, but the properties of single channels mediating their mechanosensitivity remain uncharacterized. The aim of this work was to investigate single mechano-gated channels (MGCs) activated by mechanical deformations of cardiac fibroblasts. Methods Currents through single MGCs and mechanosensitive whole-cell currents were recorded from isolated rat atrial fibroblasts using the cell-attached and whole-cell patch-clamp configurations respectively. Defined mechanical stress was applied via the patch pipette used for the whole-cell recordings. Results Under resting conditions occasional short openings of two types of single MGCs …
Acetylsalicylic acid reduces heat responses in rat nociceptive primary sensory neurons – evidence for a new mechanism of action
2002
Acetylsalicylic acid (ASA) is thought to exert its peripheral analgesic effects via inhibition of cyclooxygenase. We now studied the effects of ASA on heat responses in primary nociceptive neurons by whole-cell patch-clamp and calcium microfluorimetry experiments. Heat-evoked inward currents in acutely dissociated rat dorsal root ganglion neurons were significantly reduced by ASA in a dose-dependent and reversible manner (IC(50) 375 nM, Hill slope -2.2, maximum effect 55%). Heat-evoked calcium transients (measured with FURA-2) were reversibly reduced by 53+/-14% (P0.05) by co-application of 1 microM ASA. The low IC(50) value, the rapid occurrence, and the reversibility of the observed effec…
Phosphorylation of extracellular signal-related protein kinase is required for rapid facilitation of heat-induced currents in rat dorsal root ganglio…
2005
A subgroup of dorsal root ganglion (DRG) neurons responds to noxious heat with an influx of cations carried by specific ion channels such as the transient receptor potential channel of the vanilloid receptor type, subtype 1 (TRPV1). Application of capsaicin induces a reversible facilitation of these currents. This facilitation could be an interaction of two agonists at their common receptor or be caused by an influx of calcium ions into the cell. Calcium influx into the cell can activate protein kinases such as the extracellular signal-related protein kinase (ERK) pathway. This study explored the kinetics, calcium-dependency and intracellular signals following application of capsaicin and l…
Functional Synaptic Projections onto Subplate Neurons in Neonatal Rat Somatosensory Cortex
2002
Subplate neurons (SPn) play an important role in the formation of thalamocortical connections during early development and show glutamatergic and GABAergic spontaneous synaptic activity. We characterized these synaptic inputs by performing whole-cell recordings from SPn in somatosensory cortical slices of postnatal day 0-3 rats. At -70 mV, electrical stimulation of the thalamocortical afferents elicited in 68% of the SPn a monosynaptic CNQX-sensitive postsynaptic current (PSC). These fast PSCs were mediated by AMPA receptors, because they were prolonged by cyclothiazide and blocked by GYKI 52466. On membrane depolarization, thalamocortical stimulation elicited in 50% of the cells an additio…
Convergence of Cortical and Sensory Driver Inputs on Single Thalamocortical Cells
2013
Ascending and descending information is relayed through the thalamus via strong, "driver" pathways. According to our current knowledge, different driver pathways are organized in parallel streams and do not interact at the thalamic level. Using an electron microscopic approach combined with optogenetics and in vivo physiology, we examined whether driver inputs arising from different sources can interact at single thalamocortical cells in the rodent somatosensory thalamus (nucleus posterior, POm). Both the anatomical and the physiological data demonstrated that ascending driver inputs from the brainstem and descending driver inputs from cortical layer 5 pyramidal neurons converge and interac…