Cephalopods, such as sepia, squid, and octopus, show a well-developed and sophisticated control of balance particularly during prey capture and escape behaviors. There are two separate areas of sensory epithelium in cephalopod statocysts, a macula/statolith system, which detects linear accelerations (gravity), and a crista/cupula system, which detects rotational movements. The aim of this study...

The octopus arm provides a unique model for neuromuscular systems of flexible appendages. We previously reported the electrical compactness of the arm muscle cells and their rich excitable properties ranging from fast oscillations to overshooting action potentials. Here we characterize the voltage-activated ionic currents in the muscle cell membrane. We found three depolarization-activated ioni...

Lubeluzole is neuroprotective in a photochemical stroke model, whereas the (R)-enantiomer of the same molecule is not [De Ryck M, Keersmaekers R, Duytschaever H, Claes C, Clincke G, Janssen M and Van Reet G (1996) J Pharmacol Exp Ther 279:748-758]. We investigated the effects of lubeluzole and the (R)-enantiomer on voltage-sensitive Ca++ channels of isolated rat dorsal root ganglion cells, usin...

Whole-cell recording techniques were used to characterize voltage-gated membrane currents in neonatal rat olfactory receptor neurons (ORNs) in cell culture. Mature ORNs were identified in culture by their characteristic bipolar morphology, by retrograde labeling techniques, and by olfactory marker protein (OMP) immunoreactivity. ORNs did not have spontaneous activity, but fired action potential...

The effects of Cd2+ (20 μM) and different bath temperatures were used to study the contributions of two separate triggering mechanisms, L-type Ca2+current ( I Ca) and reverse mode Na+/Ca2+exchange, to excitation-contraction (E-C) coupling in cat ventricular myocytes. Ionic currents and cell shortening were studied with patch pipettes filled with K+-containing internal solution and discontinuous...

The membrane properties of isolated neurons from Helix aspersa were examined by using a new suction pipette method. The method combines internal perfusion with voltage clamp of nerve cell bodies separated from their axons. Pretreatment with enzymes such as trypsin that alter membrane function is not required. A platinized platinum wire which ruptures the soma membrane allows low resistance acce...

The ionic conductance mechanisms underlying action potential behavior in GH3 and GH4/C1 rat pituitary tumor cell lines were identified and characterized using a patch electrode voltage-clamp technique. Voltage-dependent sodium, calcium, and potassium currents and calcium-activated potassium currents were present in the GH3 cells. GH4/C1 cells possess much less sodium current, less voltage-depen...

Following up on an earlier chance observation, voltage-dependent whole-cell currents were recorded from isolated hippocampal neurons filled with the fluorescent dyes Fluo-3 and Fura-red, that were intermittently excited by 488 nm laser light. In the absence of any ion channel blocking drugs, in most cells depolarizing voltage steps initially evoked only the 'Hodgkin-Huxley' type early, fast inw...

To investigate the electrophysiology mechanisms of new anxiolytic and antidepressant drug: 4-butyl-alpha-agarofuran (AF-5), patch clamp-recording was used to test the effects of AF-5 on voltage-dependent sodium currents, voltage-dependent potassium currents, L-type voltage-dependent calcium currents and GABA dependent Cl(-) currents in primary cultured rat cortical neurons. Effects of AF-5 on K...

We have used the whole cell patch-clamp method to study pharmacological properties of low-voltage-activated (LVA) Ca2+ current in freshly dissociated neurons from dorsal root ganglia of adult rats. Inward barium current [in the presence of internal fluoride to reduce L-type high-voltage-activated (HVA) and external 1 microM omega-conotoxin GVIA to block N-type HVA current- was evoked from negat...