By using a combination of Ca2+ imaging and current-clamp recording, we previously reported that action potential (AP) conduction is reliably observed from the soma to axonal terminals in cultured cortical neurons. To extend these studies, we evaluated Ca2+ influx evoked by Na+ APs as a marker of AP conduction under conditions that are expected to lower the conduction safety factor to explore me...

We characterized the effects of the volatile anesthetic isoflurane on the ion currents that contribute to the action potential (AP) in isolated rat neurohypophysial (NHP) nerve terminals using patch-clamp electrophysiology. Mean resting membrane potential and AP amplitude were -62.3 +/- 4.1 and 69.2 +/- 2.9 mV, respectively, in NHP terminals. Two components of outward K(+) current (I(K)) were i...

Neuropeptide Y (NPY), the most abundant peptide in mammalian CNS, has been shown to inhibit excitatory neurotransmission presynaptically at the stratum radiatum-CA1 synapse in the in vitro rat hippocampal slice. We examined the site and mechanism of this inhibition in a series of in vitro intraand extracellular recordings in areas CA1 and CA3, the source of much of the excitatory synaptic input...

We investigated the hypothesis that the coronary vasomotor and cardiac electrophysiological effects of diadenosine polyphosphates (Ap(n)A) are mediated via release of nitric oxide and prostanoids. Transmembrane right ventricular action potentials, refractory periods, and coronary perfusion pressure were recorded from isolated, Langendorff-perfused guinea pig hearts studied under constant flow c...

The dipole component of the heart electric field has been analyzed in the context of distribution of the action potential onset timing and its duration. It has been demonstrated that the process of repolarization can be visualized as a sequence of layers with equal action potential (AP) completion time. Dipole moments of these layers can be calculated from the repolarization part of VCG and vis...

Action potentials (APs) are the principal physiological stimuli for neurotransmitter secretion in neurons. Most studies on stimulus-secretion coupling have been performed under voltage clamp using artificial electrical stimuli. To investigate the modulatory effects of AP codes on neural secretion, we introduce a capacitance method to study AP-induced secretion in single cells. The action potent...

The brainstem area postrema (AP) has been suggested to be one potential site of lithium's action. In order to determine whether the AP, as a central action site of lithium, is involved in the hypothalamic-pituitary-adrenal (HPA) activation by lithium, we examined lithium-induced expression of inducible cAMP early repressor (ICER) gene in the adrenal gland of rat with lesion of AP. The adrenocor...

(1) Background: Plant electrical signals are important physiological traits which reflect plant physiological state. As a kind of phenotypic data, plant action potential (AP) evoked by external stimuli—e.g., electrical stimulation, environmental stress—may be associated with inhibition of gene expression related to stress tolerance. However, plant AP is a response to environment changes and ful...

Effects of 4-aminopyridine (4-AP) on the electrical and contractile activities of the fundus and antrum of the cat stomach were studied using the sucrose-gap technique. In the fundus, low concentrations of 4-AP (up to 1 mmol/l) induced membrane depolarization and appearance of spike potentials and phasic contractions. After preliminary administration of atropine, 4-AP produced an opposite effec...