The somata of molluscan neurones respond with long trains of spikes to steady injected outward current. During such repetitive firing the maximum rate of rise of action potentials usually decreases as a result of inactivation of the transport mechanism for inward current. Significant inactivation of this transport system does not often change the peak level of the action potential (Magura, 1967...

Different K(+) currents participate in generating neuronal firing patterns. The Drosophila embryonic "giant" neuron culture system has facilitated current- and voltage-clamp recordings to correlate distinct excitability patterns with the underlying K(+) currents and to delineate the mutational effects of identified K(+) channels. Mutations of Sh and Shab K(+) channels removed part of inactivati...

The effects of scorpion venom heat resistant protein (SVHRP) (National invention patent of China, 2004-10-20, No. ZL01 1 06166.92) on the excitability of acutely isolated rat hippocampal neurons were observed by whole-cell recording and the potential molecular mechanisms underlying its antiepileptic effect were investigated further. The results showed that SVHRP could decrease the excitability ...

An essential step in understanding the function of sensory nervous systems is to characterize as accurately as possible the stimulus-response function (SRF) of the neurons that relay and process sensory information. One increasingly common experimental approach is to present a rapidly varying complex stimulus to the animal while recording the responses of one or more neurons, and then to direct...

Extracellular ATP is released from activated platelets and endothelial cells and stimulates proliferation of vascular smooth muscle cells (VSMC). We found that ATP stimulates a profound but transient activation of protein kinase A (PKA) via purinergic P2Y receptors. The specific inhibition of PKA by adenovirus-mediated transduction of the PKA inhibitor (PKI) attenuates VSMC proliferation in res...

Motor units of segmental tail muscles were recorded in awake rats following acute (1-2 days) and chronic (>30 days) sacral spinal cord transection to determine whether plateau potentials contributed to sustained motor-unit discharges after injury. This study was motivated by a companion in vitro study that indicated that after chronic spinal cord injury, the tail motoneurons of the sacrocaudal ...

PURPOSE Increased expression of FGFR-4 and its ligands have been linked to lethal prostate cancer (PCa). Furthermore, a germ line polymorphism in the FGFR-4 gene, resulting in arginine at codon 388 (Arg³⁸⁸) instead of glycine (Gly³⁸⁸), is associated with aggressive disease. The FGFR-4 Arg³⁸⁸ variant results in increased receptor stability, sustained receptor activation, and increased motility a...

Triple stimulation technique (TST) has previously shown that transcranial magnetic stimulation (TMS) fails to activate a proportion of spinal motoneurons (MNs) during motor fatigue. The depression in size of the TST response, but no attenuation of the conventional motor-evoked potential, suggested increased probability of repetitive spinal MN activation during exercise, even if some MNs failed ...

Certain neurons of vertebrates are specialized for high-frequency firing. Interestingly, high-frequency firing is also seen in central neurons in basal bilateral metazoans. Recently, the role of potassium currents with rightward-shifted activation curves in producing high-frequency firing has come under scrutiny. We apply intracellular recording, patch-clamp techniques, and compartmental modeli...

Electrical stimulation in the globus pallidus (GP) leads to complex modulations of neuronal activity in the stimulated nucleus. Multiple in vivo studies have demonstrated the modulation of both firing rates and patterns during and immediately following the GP stimulation. Previous in vitro studies, together with computational studies, have suggested the involvement of short-term synaptic plasti...