The emission and collection of current from satellites or rockets in the ionosphere is a process which, at equilibrium, requires a balance between inward and outward currents. In most active experiments in the ionosphere and magnetosphere, the emitted current exceeds the integrated thermal current by one or more orders of magnitude. The system response is typically for the emitted current to be...

Following up on an earlier chance observation, voltage-dependent whole-cell currents were recorded from isolated hippocampal neurons filled with the fluorescent dyes Fluo-3 and Fura-red, that were intermittently excited by 488 nm laser light. In the absence of any ion channel blocking drugs, in most cells depolarizing voltage steps initially evoked only the 'Hodgkin-Huxley' type early, fast inw...

The role of L-type calcium current ( I Ca,L) in impulse generation was studied in single sinoatrial nodal myocytes of the rabbit, with the use of the amphotericin-perforated patch-clamp technique. Nifedipine, at a concentration of 5 μM, was used to block I Ca,L. At this concentration, nifedipine selectively blocked I Ca,L for 81% without affecting the T-type calcium current ( I Ca,T), the fast ...

Particles with different energies produce varying contributions to the total ring current energy density as the storm progresses. Ring current energy densities and total ring current energies were obtained using particle data from the Polar CAMMICE/MICS instrument during several storms observed during the years 1996–1998. Four different energy ranges for particles are considered: total (1–200 k...

The electrical properties of enzymatically isolated olfactory receptor cells were studied with whole-cell patch clamp. Voltage-dependent currents could be separated into three ionic components: a transient inward sodium current, a sustained inward calcium current, and an outward potassium current. Three components of the outward current could be identified by their gating and kinetics: a calciu...

Previous reports from this laboratory have shown that a high percentage of neurons in the caudal hypothalamus are stimulated by hypoxia both in vivo and in vitro. This stimulation is in the form of an increase in firing frequency and significant membrane depolarization. The goal of the present study was to determine if this hypoxia-induced excitation is influenced by development. In addition, w...

Metabotropic glutamate receptors modulate neuronal excitability via a multitude of mechanisms, and they have been implicated in the pathogenesis of neurodegenerative processes. Here we investigated the responses mediated by group I metabotropic glutamate receptors (mGluRs) in dopamine neurons of the rat substantia nigra pars compacta, using whole cell patch-clamp recordings in combination with ...

Increased firing of cholinergic neurons of the laterodorsal tegmental nucleus (LDT) plays a critical role in generating the behavioral states of arousal and rapid eye movement sleep. The majority of these neurons exhibit a prominent transient potassium current (IA) that shapes firing but the properties of which have not been examined in detail. Although IA has been reported to be blocked by int...

Enzymatic dispersion has been used to yield single cells from segments of bullfrog atrium. Previous data (Hume and Giles, 1981) have shown that these individual cells are quiescent and have normal resting potentials and action potentials. The minimum DC space constant is approximately 920 microns. The major goals of the present study were: (a) to develop and refine techniques for making quantit...

Nictonic cholinergic responses have been previously documented in mammalian retinal ganglion cells. In the present study, dissociated retinal cells were densely plated and grown in a specific batch of rat serum. When held at negative potentials during whole-cell recording with a patch electrode, the retinal ganglion cells located close to presumptive cholinergic amacrine cells in these cultures...