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T-type voltage-gated calcium channels are expressed in the dendrites of many neurons, although their functional interactions with postsynaptic receptors and contributions to synaptic signaling are not well understood. We combine electrophysiological and ultrafast two-photon calcium imaging to demonstrate that mGluR1 activation potentiates cerebellar(More)
Two-photon microscopy offers the promise of monitoring brain activity at multiple locations within intact tissue. However, serial sampling of voxels has been difficult to reconcile with millisecond timescales characteristic of neuronal activity. This is due to the conflicting constraints of scanning speed and signal amplitude. The recent use of(More)
T-type calcium channels (the Ca(V)3 channel family) are involved in defining the resting membrane potential and in neuronal activities such as oscillations and rebound depolarization. Their physiological roles depend upon the channel activation and inactivation kinetics. A fast inactivation that stops the ionic flux of calcium in tens of milliseconds has(More)
The calcium currents of rat sensory neurones (of the IX and X cranial nerves) grown in culture were studied using whole cell recordings. In cells loaded with CsCl, and bathed in a solution where Na was replaced by choline or Tris, a step depolarization from −80 mV to 0 mV elicited the well-documented sustained Ca current (i Ca,s). In contrast,(More)
Ca2+ entry into neuronal cells is modulated by the activation of numerous G-protein-coupled receptors (GPCRs). Much effort has been invested in studying direct G-protein-mediated inhibition of voltage-dependent CaV2 Ca2+ channels. This inhibition occurs through a series of convergent modifications in the biophysical properties of the channels. An integrated(More)
On porcine intermediate lobe (IL) endocrine cells, spontaneously opening chloride channels have been studied and compared to GABA-A activated chloride channels. Elementary currents were recorded mainly from outside-out patches excised from IL cells maintained in culture for 1–4 weeks. Spontaneous inward currents were observed in Cs-loaded cells after(More)
Porcine intermediate lobe (IL) endocrine cells maintained in primary culture have been studied using patch-clamp derived configurations to record unitary activity on outside-out vesicles. Solutions were devised so as to record Cl current in isolation and to fix cytoplasmic Ca concentration [Ca]i between 0.1 μM and 3 μM. Between [Ca]i 0.5 and 1 μM, the(More)
The nanoscale size and unique optical properties of semiconductor quantum dots (QDs) have made them attractive as central photoluminescent scaffolds for a variety of biosensing platforms. In this report we functionalize QDs with dye-labeled peptides using two different linkage chemistries to yield Förster resonance energy transfer (FRET)-based sensors(More)
Using the patch-clamp technique in whole-cell configuration we have investigated the effect of increasing the internal calcium concentration (Cai) from below 10−8 M to 10−6 M on the three calcium currents: ICa, T (T for transient), ICa, S (S for sustained), ICa, N (N for neither), recently described in rat sensory neurones> Increasing Cai led to a(More)
Ion sensors based on colloidal nanoparticles (NPs), either as actively ion-sensing NPs or as nanoscale carrier systems for organic ion-sensing fluorescent chelators typically require a charged surface in order to be colloidally stable. We demonstrate that this surface charge significantly impacts the ion binding and affects the read-out. Sensor read-out(More)