Adrenaline is known to affect action potentials induced by the step current injection in an olfactory receptor cell (ORC). It is unclear, however, whether it also modulates action potentials induced by odor stimuli. In the present study, the effects of adrenaline on action potentials in ORCs were investigated quantitatively using a computer simulation. Adrenaline suppressed simulated action pot...

Mammalian photoreceptors are hyperpolarized by a light stimulus and are commonly thought to be nonspiking neurons. We used the whole-cell patch-clamp technique on surgically excised human retina to examine whether human photoreceptors can elicit action potentials. We discovered that human rod photoreceptors express voltage-gated Na(+) channels, and generate Na(+) action potentials, in response ...

A theoretical and numerical analysis of the Hodgkin-Huxley equations with the inclusion of stochastic channel dynamics is presented. It is shown that the system can be approximated by a one-dimensional bistable Langevin equation. Spontaneous action potentials can arise from the channel fluctuations and are analogous to escape by a particle over a potential barrier. The mean firing rate can be c...

Hoffman, Dax A. and Daniel Johnston. Neuromodulation of denM E T H O D S dritic action potentials. J. Neurophysiol. 81: 408–411, 1999. The Hippocampal slices (400 mm thick) from Sprague-Dawley rats, extent to which regenerative action potentials invade hippocampal 5–8 wk old, were prepared as described previously (Hoffman CA1 pyramidal dendrites is dependent on both recent activity and and John...

The effects of catecholamines (adrenaline, noradrenaline and isoproterenol) on ionic conductance changes during the generation of action potentials of bullfrog sympathetic and spinal ganglion cells were studied with intracellular microelectrodes. In sympathetic ganglion cells, adrenaline (3X10(-5)-1X10(-3)M) reversibly decreased the peak amplitude and positive after-potential of action potentia...

In this report, it was intended to analyze gastric and duodenal action potentials with use of the medical computer. Ten mongrel dogs weighing about 10 kg were used for the experiments. Under the anesthesia with pentotal sodium administered intravenously or intraperitoneally, abdominal cavity was opened. Bipolar platinum-electrodes were implanted into subserosal tissue of the antrum for the reco...

This Article contains an error in the plot for Verapamil in Figure 5, where the red and black lines representing simulations of human ventricular action potentials under control conditions and in the presence of the drugs have been inverted. The correct Figure 5 appears below as Figure 1. In addition, there are errors in the order of the legends of Figures 4, 5 and 6. The correct legends are: F...

Intramuscular electromyographic (EMG) signals are detected with needles or wires inserted into muscles. With respect to non-invasive techniques, intramuscular electromyography has high selectivity for individual motor unit action potentials and is thus used to measure motor unit activity. Decomposition of intramuscular signals into individual motor unit action potentials consists in detection a...

In cortical neurones, analogue dendritic potentials are thought to be encoded into patterns of digital spikes. According to this view, neuronal codes and computations are based on the temporal patterns of spikes: spike times, bursts or spike rates. Recently, we proposed an 'action potential waveform code' for cortical pyramidal neurones in which the spike shape carries information. Broader soma...

Spontaneous action potentials have been described in developing sensory systems. These rhythmic activities may have instructional roles for the functional development of synaptic connections. The importance of spontaneous action potentials in the developing auditory system is underpinned by the stark correlation between the time of auditory system functional maturity, and the cessation of spont...