Odorants activate sensory transduction in olfactory receptor neurons (ORNs) via a cAMP-signaling cascade, which results in the opening of nonselective, cyclic nucleotide-gated (CNG) channels. The consequent Ca2+ influx through CNG channels activates Cl channels, which serve to amplify the transduction signal. We investigate here some general properties of this Ca-activated Cl channel in rat, as...

the effect of four citrus rootstocks {sour orange (citrus aurantium), bakraeii (c. reticulata × c. limetta, mexican lime (c. aurantifolia) and volkamerlemon (c. volkameriana)} were evaluated on sweet lime leaf chlorophyll content and mineral concentrations (n, p, k, ca, na, mg, fe, zn, mn, cl, cu, and b) in a completely randomized design of four replications. budded sweet lime on the above root...

1. Reasons are given for believing that the uptake of Na(+), Cl(-), and NaCl by the crayfish occurs through the gills. 2. A crayfish in fresh water, with a Cl concentration of about 0.2 mEq./l., can) by active Cl absorption, compensate entirely for Cl lost in the urine. 3. The carbonic anhydrase activity of the gills is markedly higher than that of other tissues of the crayfish, but the equival...

Polarized Ca(2+) signals that originate at and spread from the apical pole have been shown to occur in acinar cells from lacrimal, parotid, and pancreatic glands. However, "local" Ca(2+) signals, that are restricted to the apical pole of the cell, have been previously demonstrated only in pancreatic acinar cells in which the primary function of the Ca(2+) signal is to regulate exocytosis. We sh...

In vertebrate olfactory receptor neurons (ORNs), odorant-induced activation of the transduction cascade culminates in production of cyclic AMP, which opens cyclic nucleotide-gated channels in the ciliary membrane enabling Ca(2+) influx. The ensuing elevation of the intraciliary Ca(2+) concentration opens Ca(2+)-activated Cl(-) channels, which mediate an excitatory Cl(-) efflux from the cilia. I...

Mechanisms of presynaptic inhibition were examined in giant presynaptic terminals of retinal bipolar neurons, which receive GABAergic feedback synapses from amacrine cells. Two distinct inhibitory actions of GABA are present in the terminals: a GABAA-like Cl conductance and a GABAB-like inhibition of voltage-dependent Ca current. Both of the receptors underlying these actions have unusual pharm...

Heterologous expression of a variety of membrane proteins in Xenopus oocytes sometimes results in the appearance of a hyperpolarization-activated inward current. The nature of this current remains incompletely understood. Some investigators have suggested that this current is a Cl current, whereas others have identified it as a nonselective cation current. The purpose of this investigation was ...