The pacemaker ganglion of the lobster heart is a functionally complete neural structure of nine cells which is capable of spontaneously producing bursts of actionpotential discharges separated by periods of relative inactivity. The burst discharge is maintained even when the ganglion is completely removed from the heart. The somata of five of the nine cells are quite large, approximately 60 /i ...

Flow cytometry is in use for the assessment of different cell subsets' prevalence for decades. However, the development of specific dyes sensitive for the quickly changing intracellular analytes provided an opportunity for the real-time monitoring of intracellular processes with flow cytometry. In these kinetic measurements additionally to cell prevalence values the time as a novel variable is ...

A description is given of apparatus and technique for carrying out cine photography and video recording of anterior segment fluorescein angiography. We found cine best for single-frame analysis and video tape recording less expensive.

Neurons in the thalamic ventral posterior (VB) nucleus of the cat were investigated by extracellular and intracellular recording and by anatomical methods involving either the retrograde transport of horseradish peroxidase (HRP) or the intracellular injection of HRP. Two morphological types of neurons could be detected by retrograde labeling from small injections of HRP in the internal capsule ...

Alterations in intracellular Ca(2+) concentration are amongst the most rapid responses to a variety of stimuli in mammalian cells. In the nervous system in particular, responses occur within nanoseconds. A major challenge in intracellular Ca(2+) analysis is to achieve measurements within this very fast time frame. To date, the dynamic intracellular Ca(2+) concentration has been monitored by con...

Uncovering the functional properties of individual synaptic inputs on single neurons is critical for understanding the computational role of synapses and dendrites. Previous studies combined whole-cell patch recording to load neurons with a fluorescent calcium indicator and two-photon imaging to map subcellular changes in fluorescence upon sensory stimulation. By hyperpolarizing the neuron belo...

Bitter substances are a structurally diverse group of compounds that appear to act via several transduction mechanisms. The bitter-tasting denatonium ion has been proposed to act via two different G-protein-regulated pathways, one involving inositol 1,4, 5-trisphosphate and raised intracellular calcium levels, the other involving phosphodiesterase and membrane depolarization via a cyclic nucleo...

Simultaneous recording of membrane potentials and contractility in isolated rat atria by means of intracellular micro-electrodes and a sensitive strain gage has been used to establish the normal characteristics of the tissue as well as effects of temperature, stimulus frequency and initial tension on muscle. Preliminary correlations between duration of the action potential and the degree of con...