Electrocardiograms and cardiac electrograms now frequently are measured for both clinical and experimental purposes by direct digital sampling, with no recording of the signal in analog form. This study examined the question of what sampling rates were required to measure accurately the continuous waveforms from the digital samples. Body surface waveforms and intracellular and extracellular wav...

The central nucleus of the inferior colliculus (IC) is a major integrative center in the central auditory system. It receives information from both the ascending and descending auditory pathways. To determine how single IC neurons integrate information over a wide range of sound frequencies and sound levels, we examined their intracellular responses to frequency-modulated (FM) sounds in awake l...

Regulation of an intracellular acidic environment plays a pivotal role in biological processes and functions. However, spatiotemporal analysis of the acidification in complex tissues of living subjects persists as an important challenge. We developed a photo-inactivatable bioluminescent indicator, based on a combination of luciferase-fragment complementation and a photoreaction of a light, oxyg...

Evoked excitatory postsynaptic potentials (EPSPs) were simultaneously intracellularly recorded in two lumbar motoneurons located in spinal segments 8-10 in response to intraaxonal stimulation of a descending fiber. Their mean amplitudes, paired-pulse facilitation, and short- and long-term posttetanic potentiation were compared to reveal possible functional differences among synapses formed by o...

in the present study, the effects of formalin as a peripheral noxious stimulus on spontaneously active units of the nucleus reticularis paragigantocellularis (pgi), a narrow region of the ventral pontine reticular formation, was examined in urethane anesthetized rats. spontaneous discharge of the pgi neurons was variable, ranging from i to 37 spikes per second. formalin as a chemical irritant a...

s; no of words: 237 13 Number of figures: 8; number of tables: 2 14 Correspondence to: 15 Claire Meehan 16 University of Copenhagen, 17 Department of Neuroscience and Pharmacology 18 Panum Institute, bldg 18.5 19 Blegdamsvej 3 2

The electrical properties of the water mold Achlya bisexualis were investigated using intracellular microelectrodes. Hyphae growing in a defined medium maintained a membrane potential (Vm) of -150 to -170 mV, interior negative. Under the conditions used here, this potential was insensitive to changes in the inorganic ion composition of the medium. Changes in external pH did affect Vm, but only ...

Semiconductor nanowires and other semiconducting nanoscale materials configured as field-effect transistors have been studied extensively as biological/chemical (bio/chem) sensors. These nanomaterials have demonstrated high-sensitivity from one- and two-dimensional sensors, although the realization of the ultimate pointlike detector has not been achieved. In this regard, nanoscale p-n diodes ar...

The activities of groups of neurons in a circuit or brain region are important for 21 neuronal computations that contribute to behaviors and disease states. Traditional extracellular 22 recordings have been powerful and scalable, but much less is known about the intracellular 23 processes that lead to spiking activity. We present a robotic system, the multipatcher, capable of 24 automatically o...

We developed a hyperbaric chamber for intracellular recording in rat brain stem slices during continuous compression and decompression of the tissue bath with the inert gas helium. Air, rather than helium, was also used as the compression medium in some cases to increase tissue nitrogen levels. An important feature is the chamber door, which opens or closes rapidly at 1 atmosphere absolute (ATA...