The anterior pituitary is an endocrine gland that controls basic body functions. Pituitary cell functioning depends on membrane excitability, which induces cytosolic calcium rises. Here, we reported the first identification of small-amplitude voltage fluctuations that controlled spike firing in endocrine cells recorded in situ. Three patterns of voltage fluctuations were distinguishable by thei...

AIM To study the effects of adrenoceptor agonists on the stellate ganglion neurons. METHODS Intracellular recordings were made from neurons of the isolated rat stellate ganglia. RESULTS Noradrenaline and clonidine (10-30 mumol.L-1) reversibly depressed 3 types of calcium-dependent potentials, namely, the action potential shoulder; the spike after-hyperpolarization; the Ca2+ spike evoked in ...

Low-threshold calcium current (LTCC) in thalamic neurons is important in generation of normal thalamocortical rhythms, and may be involved in the genesis of abnormal activities such as spike-wave discharges that characterize petit mal epilepsy. Ethosuximide and dimethadione, anticonvulsants effective in petit mal, reduced the LTCC when applied to thalamic neurons at clinically relevant concentr...

Distinct activity patterns in subthalamic nucleus (STN) neurons are observed during normal voluntary movement and abnormal movement in Parkinson's disease (PD). To determine how such patterns of activity are regulated by small conductance potassium (SK)/calcium-activated potassium (KCa) channels and voltage-gated calcium (Cav) channels, STN neurons were recorded in the perforated patch configur...

Following stimulation with a calcium-mobilizing agonist there is often a distinct latency (L) preceding the onset of the first calcium spike. In the continued presence of the agonist, repetitive spikes appear separated by a variable period (P). The relationship between L and P has been investigated in an insect salivary gland responding to 5-hydroxytryptamine (5-HT). Both L and P were found to ...

While firing rate is well established as a relevant parameter for encoding information exchanged between neurons, the significance of other parameters is more conjectural. Here, we show that regularity of neuronal spike activities affects sensorimotor processing in tottering mutants, which suffer from a mutation in P/Q-type voltage-gated calcium channels. While the modulation amplitude of the s...

Granule cells excitability in the turtle olfactory bulb was analyzed using whole cell recordings in current- and voltage-clamp mode. Low-threshold spikes (LTSs) were evoked at potentials that are subthreshold for Na spikes in normal medium. The LTSs were evoked from rest, but hyperpolarization of the cell usually increased their amplitude so that they more easily boosted Na spike initiation. Th...

As recent advances in calcium sensing technologies facilitate simultaneously imaging action potentials in neuronal populations, complementary analytical tools must also be developed to maximize the utility of this experimental paradigm. Although the observations here are fluorescence movies, the signals of interest--spike trains and/or time varying intracellular calcium concentrations--are hidd...

We have previously shown that the nucleocapsid protein of SARS-associated coronavirus (SARS-CoV) activated cyclooxygenase-2 (COX-2) expression. In this study, we identified another viral protein, the spike of SARS-CoV, which played an important role in virus-stimulated COX-2 expression after screening all genes from the SARS-CoV genome. We found that an upstream calcium-dependent PKC isozyme PK...