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1. The membrane properties of cone inner segments dissociated enzymatically from monkey retina were studied under voltage-clamp conditions using patch pipettes in the whole-cell clamp configuration. 2. A noninactivating, voltage-gated calcium current was evoked at potentials positive to -60 mV and peaked between -30 and -20 mV when barium was substituted(More)
1. Single, isolated, rod photoreceptors were obtained by enzymatic dissociation of the tiger salamander (Ambystoma tigrinum) retina. These solitary cells retained the morphological features of rods of the intact retina and could be maintained in culture for several days. Solitary cells were penetrated with one or two micropipettes and their(More)
We studied how intrinsic membrane properties affect the gain and temporal pattern of response in bipolar cells dissociated from retinae of tiger salamanders. Currents specified by a pseudorandom binary sequence, an m-sequence, superimposed on various means, were injected into the cells. From the resultant membrane voltage response for each mean current,(More)
THe current suppressed by light, the generator current, was studied in solitary salamander (Ambystoma tigrinum) rod photoreceptors with the single-micropipette voltage-clamp technique. The effects of Ca, cyclic GMP, and voltage were measured while voltage- and Ca-activated currents of the inner segment were blocked with Co, Cs, and TEA (tetraethylammonium).(More)
While the overall importance of Ca 2+ as a mediator of cell signaling and neurotransmitter release has long been appreciated, the details of Ca 2+ dynamics within the inner segments of vertebrate rod photoreceptors are just beginning to be elucidated. Even less is known regarding Ca 2+ dynamics within the rod presynaptic terminal compartment. Using fura-2(More)
A mouse monoclonal antibody was produced against salamander retinal membranes. It binds to the retina as well as to a wide variety of other salamander tissues and is called Sal-1. Because retinal neurons dissociated from the mature salamander retina adhere poorly to standard substrates, cells were plated onto coverslips previously treated with Sal-1. This(More)
Retinal Müller (glial) cells metabolize glucose to lactate, which is preferentially taken up by photoreceptor neurons as fuel for their oxidative metabolism. We explored whether lactate supply to neurons is a glial function controlled by neuronal signals. For this, we used subcellular fluorescence imaging and either amperometric or optical biosensors to(More)
To assess the regenerative capability of the photoreceptor synapse, we have isolated and cultured photoreceptors from the mature salamander retina. Both rod and cone photoreceptors were able to regenerate processes within 3 d of plating. Cells extended numerous actin-containing filopodia as well as a few neuritic processes. The neurites contained(More)
Adult neurons, isolated from the salamander retina, were maintained in low-density cell culture and examined for synapse formation by electrophysiological and electron microscopic techniques. Morphologically identifiable rod, cone, horizontal, bipolar, and amacrine/ganglion cells survived for many months, grew processes, and formed numerous cell contacts.(More)
Electrophysiological studies were made on microcultures (300-500 mum in diameter) in which solitary sympathetic principal neurons from newborn rats grew on previously dissociated rat heart cells. Some neurons inhibited,some excited, and others first inhibited and then excited the cardiac myocytes. Application of drugs provided evidence for secretion of(More)