Visualising functional 5-HT receptors containing A and C subunits at or near the cell surface.

Five different subunits of the human serotonin 3 (5-hydroxytrptamine 3; 5-HT) receptor exist and these are present in both central and peripheral systems. Different subunits alter the efficacy of 5-HT receptor antagonists used to treat diarrhoea predominant-irritable bowel syndrome, chemotherapy induced nausea and vomiting and depression. Cell surface arrangement of 5-HT receptor complexes and the contribution of C, D and E subunits to receptor function is poorly understood.

The C and E subunits of the serotonin 5-HT receptor subtly modulate electrical properties of the receptor.

Serotonin type 3 (5-hydroxytrptamine-3, 5-HT) receptors are ligand-gated cation channels present in both central and peripheral nervous systems. In humans there are five different subunits (A, B, C, D and E) of 5-HT receptors which can form homomeric or heteromeric receptors that may account for discrepancies in patient responses to treatments. The present study commences characterisation of the profiles of human 5-HT receptors containing C and/or E subunits.

Spontaneous electrical activity recorded from the aphid central nervous system.

Whilst many classes of insecticides target the insect central nervous system (CNS), their effects in the CNS of pest aphids have not been demonstrated. In this report, we describe an electrophysiological method for recording spontaneous neuronal activity from the giant willow aphid (Tuberolachnus salignus). Using extracellular recording electrodes and two analysis methods (threshold and template search), spontaneous spike activity was shown to exhibit sensitivity to the neuroexcitatory insecticide imidacloprid.

Contractility and pacemaker cells in the prostate gland.

Purpose: We focused on the current opinion on mechanisms generating stromal tone in the prostate gland.

Materials And Methods: We selected the guinea pig as the main species for investigation since its prostate has a high proportion of smooth muscle that undergoes age related changes similar in many respects to that in humans. The main techniques that we used were tension recording and electrophysiology.

Spontaneous electrical waveforms in aging guinea pig prostates.

Purpose: We characterized spontaneous electrical activity in the aging guinea pig prostate.

Materials And Methods: Membrane potential recordings were made using conventional single microelectrode recording techniques.

Results: Three types of spontaneous waveforms were recorded, including spikes, slow waves and spontaneous transient depolarizations.

Inositol trisphosphate-dependent Ca stores and mitochondria modulate slow wave activity arising from the smooth muscle cells of the guinea pig prostate gland.

Background And Purpose: Changes in smooth muscle tone of the prostate gland are involved in aetiology of symptomatic prostatic hyperplasia, however the control mechanisms of prostatic smooth muscle are not well understood. Here, we have examined the role of internal Ca(2+) compartments in regulating slow wave activity in the guinea pig prostate.

Experimental Approach: Standard intracellular membrane potential recording techniques were used.

alpha(1)-adrenoceptor modulation of spontaneous electrical waveforms in the guinea-pig prostate.

The aim of this study was to investigate the effects of phenylephrine on the spontaneous slow wave and pacemaker activity in the guinea-pig prostate. Membrane potential recordings were made using intracellular microelectrodes. Guinea-pig prostatic cells either displayed 'slow wave' activity or 'pacemaker' potentials.

Spontaneous electrical activity in the prostate gland.

The cellular mechanisms that underlie the initiation, maintenance and propagation of electrical activity in the prostate gland remain little understood. Intracellular microelectrode recordings have identified at least two distinct electrical waveforms: pacemaker potentials and slow wave activity. By analogy with the intestine, we have proposed that pacemaker activity arises from a morphologically distinct group of c-Kit positive interstitial cells that lie mainly between the glandular epithelium and smooth muscle layers.

Characterization of spontaneous depolarizations in smooth muscle cells of the Guinea pig prostate.

Purpose: We characterized the electrical events recorded in small segments of the dorsal lobe of the prostate of immature male guinea pigs and examined some mechanisms underlying their generation.

Material And Methods: Membrane potential recordings were made in the stroma of the guinea pig prostate using conventional single microelectrode techniques.

Results: Three distinct, spontaneously occurring electrical events were recorded in guinea pig prostate, namely slow waves, consisting of a depolarizing transient 14 mV in amplitude with 1 to 6 nifedipine sensitive spikes superimposed, pacemaker potentials, consisting of a larger depolarization 40 mV in amplitude, and STDs 1 to 10 mV in amplitude.