isolation and characterization of the membrane
... The membrane envelope enclosing the bacteroids in soybean root nodules is shown by ultrastructural and biochemical studies to be derived from, and to retain the characteristics of, the host cell plasma membrane. During the early stages of the infection process, which occurs through an invagination, ...
... The membrane envelope enclosing the bacteroids in soybean root nodules is shown by ultrastructural and biochemical studies to be derived from, and to retain the characteristics of, the host cell plasma membrane. During the early stages of the infection process, which occurs through an invagination, ...
Chapter 2: Nerve Cells and Nerve Impulses
... 8. Neurons differ most strongly from other body cells in their: a. temperature. b. shape. c. osmotic pressure. d. mitochondria. ANS: B and Glia ...
... 8. Neurons differ most strongly from other body cells in their: a. temperature. b. shape. c. osmotic pressure. d. mitochondria. ANS: B and Glia ...
Chapter 2: Nerve Cells and Nerve Impulses
... 8. Neurons differ most strongly from other body cells in their: a. temperature. b. shape. c. osmotic pressure. d. mitochondria. ANS: B and Glia ...
... 8. Neurons differ most strongly from other body cells in their: a. temperature. b. shape. c. osmotic pressure. d. mitochondria. ANS: B and Glia ...
Electrophysiological Identification of Tonic and Phasic Neurons in
... excitability of tonic, but not phasic, type of celiac ganglion neurons. Ditting et al. (2009) also suggested that the greater susceptibility of renal afferent neurons correlated with the higher rate of tonic firings and further contributed to inflammatory process in the kinedy. These results are of ...
... excitability of tonic, but not phasic, type of celiac ganglion neurons. Ditting et al. (2009) also suggested that the greater susceptibility of renal afferent neurons correlated with the higher rate of tonic firings and further contributed to inflammatory process in the kinedy. These results are of ...
LVA and HVA Ca Currents in Ventricular Muscle Cells of the
... been shown to enhance the amplitude of a number of types of voltage-gated Ca21 currents (Bean 1989a; Tsien et al. 1988), as well as being able to block certain K1 currents (Armstrong and Taylor 1980; Hille 1992; Latorre and Miller 1983). Its substitution for Ca21 in the extracellular solution would ...
... been shown to enhance the amplitude of a number of types of voltage-gated Ca21 currents (Bean 1989a; Tsien et al. 1988), as well as being able to block certain K1 currents (Armstrong and Taylor 1980; Hille 1992; Latorre and Miller 1983). Its substitution for Ca21 in the extracellular solution would ...
PDF - American Chemical Society
... decrease in intensity with changing electrode potential but do not shift; i.e., they behave in a manner that is characteristic of solution species. In contrast, the intense broad band located between the bands due to solution-phase species shifts to higher wavenumber with increasingly positive elect ...
... decrease in intensity with changing electrode potential but do not shift; i.e., they behave in a manner that is characteristic of solution species. In contrast, the intense broad band located between the bands due to solution-phase species shifts to higher wavenumber with increasingly positive elect ...
Lipid Characterization of an Enriched Plasma Membrane
... membrane of Dunaliella must not only remain functional under the high external concentrations of NaCl, but also maintain a permeability barrier against the high NaCl concentration outside of the cell. Indeed, internal Na+ concentrations of less than 100 mm have been reported in Dunaliella cells grow ...
... membrane of Dunaliella must not only remain functional under the high external concentrations of NaCl, but also maintain a permeability barrier against the high NaCl concentration outside of the cell. Indeed, internal Na+ concentrations of less than 100 mm have been reported in Dunaliella cells grow ...
theta oscillation in the hippocampus
... pal-entorhinal theta oscillation is the medial septum and the vertical limb of the diagonal band of Broca (Petsche et al., 1962). Cholinergic cells of the septal region innervate both principal cells and interneurons of the hippocampus (Leranth and Frotscher, 1987), whereas the septohippocampal GABA ...
... pal-entorhinal theta oscillation is the medial septum and the vertical limb of the diagonal band of Broca (Petsche et al., 1962). Cholinergic cells of the septal region innervate both principal cells and interneurons of the hippocampus (Leranth and Frotscher, 1987), whereas the septohippocampal GABA ...
Read as PDF
... mediate potentiating effects of depolarization on synaptic transmission. Recently there has been renewed interest in a type of plasticity in which a neuron’s somatic membrane potential influences synaptic transmission. We study mechanisms that mediate this type of control at a synapse between a mech ...
... mediate potentiating effects of depolarization on synaptic transmission. Recently there has been renewed interest in a type of plasticity in which a neuron’s somatic membrane potential influences synaptic transmission. We study mechanisms that mediate this type of control at a synapse between a mech ...
actin filament-membrane attachment: are membrane particles
... technique to determine whether membrane particles are involved in the attachment of actin filaments to the membrane. If particles are involved, the attachment of the actin filaments to membranes is by integral membrane proteins or proteins situated at least in part within the lipid bilayer. We selec ...
... technique to determine whether membrane particles are involved in the attachment of actin filaments to the membrane. If particles are involved, the attachment of the actin filaments to membranes is by integral membrane proteins or proteins situated at least in part within the lipid bilayer. We selec ...
Intracellular Features Predicted by Extracellular
... Here we focus our attention on unit detection in the rat hippocampal area CA1. Extracellular recording methods traditionally provide information only on whether a neuron fires a spike or not. To obtain information about subthreshold variations in neuronal membrane potential, it is necessary to use i ...
... Here we focus our attention on unit detection in the rat hippocampal area CA1. Extracellular recording methods traditionally provide information only on whether a neuron fires a spike or not. To obtain information about subthreshold variations in neuronal membrane potential, it is necessary to use i ...
Axonal Membranes and Their Domains: Assembly and Function of
... using spinal motor neurons, demonstrated that ankyrin-G is first expressed along the length of the axon before gradually becoming restricted to the proximal axon at embryonic day 13.5 (Le Bras et al., 2014). It is not clear whether these findings represent a difference in assembly of the AIS in a br ...
... using spinal motor neurons, demonstrated that ankyrin-G is first expressed along the length of the axon before gradually becoming restricted to the proximal axon at embryonic day 13.5 (Le Bras et al., 2014). It is not clear whether these findings represent a difference in assembly of the AIS in a br ...
Calcium diffusion models and transmitter release in
... extensions of this model to more demanding stimulus regimens (8). For example, during a tetanus of 100 action potentials at 20 Hz, synaptic facilitation grows and decays with the same components as for a single spike, plus a new, slow, seconds-long component. This is remarkably similar to the accumu ...
... extensions of this model to more demanding stimulus regimens (8). For example, during a tetanus of 100 action potentials at 20 Hz, synaptic facilitation grows and decays with the same components as for a single spike, plus a new, slow, seconds-long component. This is remarkably similar to the accumu ...
Excitation of Rat Locus Coeruleus Neurons by Adenosine 5
... varicose terminals of the noradrenergic cells as they ramify in their several targets, but also from the soma-dendritic region (Egan et al., 1983). Here it acts at a,-adrenoceptors to hyperpolarize the cell and inhibit firing; its effect is detected electrophysiologically as an IPSP (Egan et al., 19 ...
... varicose terminals of the noradrenergic cells as they ramify in their several targets, but also from the soma-dendritic region (Egan et al., 1983). Here it acts at a,-adrenoceptors to hyperpolarize the cell and inhibit firing; its effect is detected electrophysiologically as an IPSP (Egan et al., 19 ...
Potassium channels in C. elegans
... channels are widely expressed in brain, muscle and heart where they control complex waveforms of electrical activity. They are also widely expressed in tissues outside the nervous system such as cells of the immune system (Cahalan and Chandy, 1997). Four conserved subfamilies, first cloned from Dros ...
... channels are widely expressed in brain, muscle and heart where they control complex waveforms of electrical activity. They are also widely expressed in tissues outside the nervous system such as cells of the immune system (Cahalan and Chandy, 1997). Four conserved subfamilies, first cloned from Dros ...
Synaptic Regulation of Action Potential Timing in
... 50 –200 msec, 0.2 Hz) were applied to the neostriatum to evoke monosynaptic EPSC s or I PSC s. Square wave somatic current injections (20 – 60 pA, 600 msec, 0.2 Hz) were used to generate episodes of regular spiking, with a relatively stationary interspike interval (ISI) (see Fig. 2). Stimuli were ap ...
... 50 –200 msec, 0.2 Hz) were applied to the neostriatum to evoke monosynaptic EPSC s or I PSC s. Square wave somatic current injections (20 – 60 pA, 600 msec, 0.2 Hz) were used to generate episodes of regular spiking, with a relatively stationary interspike interval (ISI) (see Fig. 2). Stimuli were ap ...
Active dendrites, potassium channels and synaptic plasticity
... The dendrites of CA1 pyramidal neurons in the hippocampus express numerous types of voltage-gated ion channel, but the distributions or densities of many of these channels are very non-uniform. Sodium channels in the dendrites are responsible for action potential (AP) propagation from the axon into ...
... The dendrites of CA1 pyramidal neurons in the hippocampus express numerous types of voltage-gated ion channel, but the distributions or densities of many of these channels are very non-uniform. Sodium channels in the dendrites are responsible for action potential (AP) propagation from the axon into ...
IRK-1 Potassium Channels Mediate Peptidergic Inhibition
... through the same G-protein in the same cell might activate distinct effectors and that specific coupling of a G-protein-coupled receptor to its effectors can be determined by factors other than its associated G-proteins. ...
... through the same G-protein in the same cell might activate distinct effectors and that specific coupling of a G-protein-coupled receptor to its effectors can be determined by factors other than its associated G-proteins. ...
Fluorescence Recordings of Electrical Activity in Goldfish Optic
... We optimized our recording system for detection of small fluorescence changes from the slices in 2 ways. First, for most of the experiments, the aperture of the luminous field diaphragm on the microscope was reduced so that an area of the slice only slightly larger than that viewed through the pinho ...
... We optimized our recording system for detection of small fluorescence changes from the slices in 2 ways. First, for most of the experiments, the aperture of the luminous field diaphragm on the microscope was reduced so that an area of the slice only slightly larger than that viewed through the pinho ...
Muscarinic Activation of a Cation Current and Associated Current
... layer-II neurons is thus fundamental for understanding the function(s) of the entorhinal-hippocampal network that is involved, at least, in the encoding of explicit memories (Scoville and Milner 1957; Squire 1998). In a previous current-clamp study, we showed that application of the cholinergic agon ...
... layer-II neurons is thus fundamental for understanding the function(s) of the entorhinal-hippocampal network that is involved, at least, in the encoding of explicit memories (Scoville and Milner 1957; Squire 1998). In a previous current-clamp study, we showed that application of the cholinergic agon ...
Tubular reabsorption
... Sodium is reabsorbed throughout the tubule with the exception of the descending limb of the loop of Henle Of the Na+ reabsorbed, on average • 67% in the proximal tubule (Plays an important role in the reabsorption of glucose, amino acids, water, chloride ions, and urea) • 25% in the loop of Henl ...
... Sodium is reabsorbed throughout the tubule with the exception of the descending limb of the loop of Henle Of the Na+ reabsorbed, on average • 67% in the proximal tubule (Plays an important role in the reabsorption of glucose, amino acids, water, chloride ions, and urea) • 25% in the loop of Henl ...
Spiking Neurons - Computing Science and Mathematics
... can evaluate and classify neuronal firing by a spike count measure - but is this really the code used by neurons in the brain ? In other words , is a neuron which receives signals from a sensory neuron only looking at and reacting to the numbers of spikes it receives in a time window of, say, 500 ms ...
... can evaluate and classify neuronal firing by a spike count measure - but is this really the code used by neurons in the brain ? In other words , is a neuron which receives signals from a sensory neuron only looking at and reacting to the numbers of spikes it receives in a time window of, say, 500 ms ...
video slide - Course
... Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings ...
... Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings ...
Nutrient and energy intakes for the European Community
... The systemic homoeostasis of potassium is understood imperfectly. Over 90 5% of dietary potassium is absorbed in the proximal small intestine, possibly by a combination of diffusional mechanisms and solvent drag. The body content is regulated by the renal glomerular filtration and tubular secretion ...
... The systemic homoeostasis of potassium is understood imperfectly. Over 90 5% of dietary potassium is absorbed in the proximal small intestine, possibly by a combination of diffusional mechanisms and solvent drag. The body content is regulated by the renal glomerular filtration and tubular secretion ...
Physiological implications of the regulation of vacuolar
... In rat cortical late distal tubules, microperfusion experiments have shown that the rate of proton secretion by H+ATPase was also dependent on chloride transport, since the inhibition of Cl- channels by 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) markedly reduced distal tubule acidification, ...
... In rat cortical late distal tubules, microperfusion experiments have shown that the rate of proton secretion by H+ATPase was also dependent on chloride transport, since the inhibition of Cl- channels by 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) markedly reduced distal tubule acidification, ...
Action potential
In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and endocrine cells, as well as in some plant cells. In neurons, they play a central role in cell-to-cell communication. In other types of cells, their main function is to activate intracellular processes. In muscle cells, for example, an action potential is the first step in the chain of events leading to contraction. In beta cells of the pancreas, they provoke release of insulin. Action potentials in neurons are also known as ""nerve impulses"" or ""spikes"", and the temporal sequence of action potentials generated by a neuron is called its ""spike train"". A neuron that emits an action potential is often said to ""fire"".Action potentials are generated by special types of voltage-gated ion channels embedded in a cell's plasma membrane. These channels are shut when the membrane potential is near the resting potential of the cell, but they rapidly begin to open if the membrane potential increases to a precisely defined threshold value. When the channels open (in response to depolarization in transmembrane voltage), they allow an inward flow of sodium ions, which changes the electrochemical gradient, which in turn produces a further rise in the membrane potential. This then causes more channels to open, producing a greater electric current across the cell membrane, and so on. The process proceeds explosively until all of the available ion channels are open, resulting in a large upswing in the membrane potential. The rapid influx of sodium ions causes the polarity of the plasma membrane to reverse, and the ion channels then rapidly inactivate. As the sodium channels close, sodium ions can no longer enter the neuron, and then they are actively transported back out of the plasma membrane. Potassium channels are then activated, and there is an outward current of potassium ions, returning the electrochemical gradient to the resting state. After an action potential has occurred, there is a transient negative shift, called the afterhyperpolarization or refractory period, due to additional potassium currents. This mechanism prevents an action potential from traveling back the way it just came.In animal cells, there are two primary types of action potentials. One type is generated by voltage-gated sodium channels, the other by voltage-gated calcium channels. Sodium-based action potentials usually last for under one millisecond, whereas calcium-based action potentials may last for 100 milliseconds or longer. In some types of neurons, slow calcium spikes provide the driving force for a long burst of rapidly emitted sodium spikes. In cardiac muscle cells, on the other hand, an initial fast sodium spike provides a ""primer"" to provoke the rapid onset of a calcium spike, which then produces muscle contraction.