Large cell motoneurons in the Cancer borealis cardiac ganglion generate rhythmic bursts of action potentials responsible for cardiac contractions. While it is well known that these burst potentials are dependent on coordinated interactions among depolarizing and hyperpolarizing conductances, the depolarizing currents present in these cells, and their biophysical characteristics, have not been t...

It is widely believed that the selectivity of voltage-dependent calcium channels is mainly controlled by amino acid residues contained within four p-loop motifs forming the pore of the channel. An examination of the amino acid sequences of high voltage-activated calcium channels reveals that their domain III S5-H5 regions contain a highly conserved motif with homology to known EF hand calcium b...

To investigate the channels and neurotransmitters in the ventrolateral medulla (VLM) oblongata that are responsible for the maintenance of sympathetic tone and cardio-respiratory reflex regulation. Microinjections of excitant amino acid (glutamate, 100 nl, 100 mM), calcium channel blockers, agonists and antagonists were made throughout the VLM in anaesthetized rats. Arterial blood pressure, sym...

We investigated the mechanisms that contribute to spontaneous regular bursting in adult Purkinje neurons in acutely prepared cerebellar slices. Bursts consisted of 3-20 spikes and showed a stereotypic waveform. Each burst developed with an increase in firing rate and was terminated by a more rapid increase in firing rate and a decrease in spike height. Whole-cell current-clamp recordings showed...

The thalamic relay neurons, reticular thalamic nucleus, and neocortical pyramidal cells form a circuit that sustains oscillatory burst firing, and is regarded as the underlying mechanism of absence seizures. T-type calcium channels play a key role in this circuit. Here, we review the role of T-type calcium channel genes in the development of absence seizures, and emphasize gain or loss of funct...

R-type calcium channels in postsynaptic spines signal through functional calcium microdomains to regulate a calcium/calmodulin-sensitive potassium channel that in turn regulates postsynaptic hippocampal long-term potentiation (LTP). Here, we ask whether R-type calcium channels in presynaptic terminals also signal through calcium microdomains to control presynaptic LTP. We focus on presynaptic L...

nimodipine, an l-type calcium channel blocker, can induce analgesia. however, it is not clear that this analgesic effect is at the level of spinal or supraspinal pain pathway. in addition, it has been reported that the analgesic effect of nifedipine, another l-type calcium channel blocker is related to the hpa axis, but there is no report indicating the role of this axis in the analgesic effect...

Viola HM, Davies SM, Filipovska A, Hool LC. The L-type Ca channel contributes to alterations in mitochondrial calcium handling in the mdx ventricular myocyte. Am J Physiol Heart Circ Physiol 304: H767–H775, 2013. First published January 18, 2013; doi:10.1152/ajpheart.00700.2012.—The L-type Ca channel is the main route for calcium entry into cardiac myocytes, and it is essential for contraction....

Background: Overdoses with cardiovascular drugs are related with significant morbidity and mortality. Beta-adrenergic blockers, calcium-channel blockers (CCBs), thiazide, digoxin and angiotensin converting enzyme (ACE) inhibitors represent five of the most important classes of cardiovascular drugs. Overdoses with cardiovascular drugs are typically caused by exploratory ingestion by children or ...