The Early Differentiation of Neuronal Membrane Properties

1984 ◽  
pp. 239-250
Author(s):  
Nicholas C. Spitzer
Keyword(s):  
Membrane Properties ◽  
Neuronal Membrane ◽  
Early Differentiation

Resting and Active Properties of Pyramidal Neurons in Subiculum and CA1 of Rat Hippocampus

2000 ◽  
Vol 84 (5) ◽  
pp. 2398-2408 ◽  
Author(s):  
Nathan P. Staff ◽  
Hae-Yoon Jung ◽  
Tara Thiagarajan ◽  
Michael Yao ◽  
Nelson Spruston
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Pyramidal Neurons ◽  
Current Injection ◽  
Synaptic Integration ◽  
Membrane Properties ◽  
Neuronal Membrane ◽  
Similar Action ◽  
Ca1 Neurons ◽  
Ca1 Pyramidal Neurons

Action potentials are the end product of synaptic integration, a process influenced by resting and active neuronal membrane properties. Diversity in these properties contributes to specialized mechanisms of synaptic integration and action potential firing, which are likely to be of functional significance within neural circuits. In the hippocampus, the majority of subicular pyramidal neurons fire high-frequency bursts of action potentials, whereas CA1 pyramidal neurons exhibit regular spiking behavior when subjected to direct somatic current injection. Using patch-clamp recordings from morphologically identified neurons in hippocampal slices, we analyzed and compared the resting and active membrane properties of pyramidal neurons in the subiculum and CA1 regions of the hippocampus. In response to direct somatic current injection, three subicular firing types were identified (regular spiking, weak bursting, and strong bursting), while all CA1 neurons were regular spiking. Within subiculum strong bursting neurons were found preferentially further away from the CA1 subregion. Input resistance ( R N), membrane time constant (τm), and depolarizing “sag” in response to hyperpolarizing current pulses were similar in all subicular neurons, while R N and τm were significantly larger in CA1 neurons. The first spike of all subicular neurons exhibited similar action potential properties; CA1 action potentials exhibited faster rising rates, greater amplitudes, and wider half-widths than subicular action potentials. Therefore both the resting and active properties of CA1 pyramidal neurons are distinct from those of subicular neurons, which form a related class of neurons, differing in their propensity to burst. We also found that both regular spiking subicular and CA1 neurons could be transformed into a burst firing mode by application of a low concentration of 4-aminopyridine, suggesting that in both hippocampal subfields, firing properties are regulated by a slowly inactivating, D-type potassium current. The ability of all subicular pyramidal neurons to burst strengthens the notion that they form a single neuronal class, sharing a burst generating mechanism that is stronger in some cells than others.

Properties of a presynaptic metabotropic glutamate receptor in rat neostriatal slices

1993 ◽  
Vol 69 (4) ◽  
pp. 1236-1244 ◽  
Author(s):  
D. M. Lovinger ◽  
E. Tyler ◽  
S. Fidler ◽  
A. Merritt
Keyword(s):  
Glutamate Receptor ◽  
Metabotropic Glutamate Receptor ◽  
Field Potential ◽  
Population Spike ◽  
Membrane Properties ◽  
Neuronal Membrane ◽  
Metabotropic Receptor ◽  
Whole Cell ◽  
Metabotropic Glutamate ◽  
Cell Recording

1. The effect of the metabotropic glutamate receptor agonist trans-1-aminocyclopentane-1,3-dicarboxylic acid (t-ACPD) on glutamatergic transmission at corticostriate synapses was examined using slices of neostriatum. Field potential recordings were performed in slices from adult animals, and the effects of t-ACPD on the synaptically driven population spike were examined. Tight-seal whole-cell recordings were made in slices from 2 to 4-wk-old rats, and effects of t-ACPD on the amplitude of excitatory postsynaptic potentials (EPSPs) and postsynaptic neuronal membrane properties were examined. In addition, the effects of putative metabotropic receptor agonists and antagonists and 4-aminopyridine were examined. The ability of these compounds to mimic t-ACPD or block its actions were determined. 2. Application of t-ACPD (5-100 microM) depressed the maximal amplitude of the synaptically driven population spike during field potential recording. This compound likewise depressed the amplitude of EPSPs observed with whole-cell recording. The 1S,3R isomer of t-ACPD was effective in depressing transmission, whereas the 1R,3S isomer was without effect at 50 microM. The cis isomer of ACPD (c-ACPD) also depressed transmission at concentrations from 25 to 100 microM. 3. Depression of population spike or EPSP amplitude by t-ACPD was not altered in the presence of the putative metabotropic receptor antagonist L-aminophosphonopropionic acid (AP3, 1 mM). In addition, the depressant action of t-ACPD on the population spike was not mimicked by aminophosphonobutyric acid, which has been shown to produce synaptic depression at other excitatory synapses.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Properties of internally perfused, voltage-clamped, isolated nerve cell bodies.

1978 ◽  
Vol 71 (5) ◽  
pp. 489-507 ◽  
Author(s):  
K S Lee ◽  
N Akaike ◽  
A M Brown
Keyword(s):  
Voltage Clamp ◽  
Nerve Cell ◽  
Action Potentials ◽  
Divalent Cations ◽  
Membrane Resistance ◽  
Membrane Properties ◽  
Neuronal Membrane ◽  
Internal Perfusion ◽  
Shunt Resistance ◽  
Membrane Function

The membrane properties of isolated neurons from Helix aspersa were examined by using a new suction pipette method. The method combines internal perfusion with voltage clamp of nerve cell bodies separated from their axons. Pretreatment with enzymes such as trypsin that alter membrane function is not required. A platinized platinum wire which ruptures the soma membrane allows low resistance access directly to the cell's interior improving the time resolution under voltage clamp by two orders of magnitude. The shunt resistance of the suction pipette was 10-50 times the neuronal membrane resistance, and the series resistance of the system, which was largely due to the tip diameter, was about 10(5) omega. However, the peak clamp currents were only about 20 nA for a 60-mV voltage step so that measurements of membrane voltage were accurate to within at least 3%. Spatial control of voltage was achieved only after somal separation, and nerve cell bodies isolated in this way do not generate all-or-none action potentials. Measurements of membrane potential, membrane resistance, and membrane time constant are equivalent to those obtained using intracellular micropipettes, the customary method. With the axon attached, comparable all-or-none action potentials were also measured by either method. Complete exchange of Cs+ for K+ was accomplished by internal perfusion and allowed K+ currents to be blocked. Na+ currents could then be blocked by TTX or suppressed by Tris-substituted snail Ringer solution. Ca2+ currents could be blocked using Ni2+ and other divalent cations as well as organic Ca2+ blockers. The most favorable intracellular anion was aspartate-, and the sequence of favorability was inverted from that found in squid axon.

scholarly journals Direct Actions of Carbenoxolone on Synaptic Transmission and Neuronal Membrane Properties

2009 ◽  
Vol 102 (2) ◽  
pp. 974-978 ◽  
Author(s):  
Kenneth R. Tovar ◽  
Brady J. Maher ◽  
Gary L. Westbrook
Keyword(s):  
Action Potential ◽  
Synaptic Transmission ◽  
Gap Junctions ◽  
Hippocampal Neurons ◽  
Electrical Coupling ◽  
Network Activity ◽  
Membrane Properties ◽  
Neuronal Membrane ◽  
Postsynaptic Currents ◽  
Gap Junctional

The increased appreciation of electrical coupling between neurons has led to many studies examining the role of gap junctions in synaptic and network activity. Although the gap junctional blocker carbenoxolone (CBX) is effective in reducing electrical coupling, it may have other actions as well. To study the non–gap junctional effects of CBX on synaptic transmission, we recorded from mouse hippocampal neurons cultured on glial micro-islands. This recording configuration allowed us to stimulate and record excitatory postsynaptic currents (EPSCs) or inhibitory postsynaptic currents (IPSCs) in the same neuron or pairs of neurons. CBX irreversibly reduced evoked α-amino-3-hydroxy-5-methyl-4-isoxazole-proprionic acid (AMPA) receptor–mediated EPSCs. Consistent with a presynaptic site of action, CBX had no effect on glutamate-evoked whole cell currents and increased the paired-pulse ratio of AMPA and N-methyl-d-aspartate (NMDA) receptor–mediated EPSCs. CBX also reversibly reduced GABAA receptor–mediated IPSCs, increased the action potential width, and reduced the action potential firing rate. Our results indicate CBX broadly affects several neuronal membrane conductances independent of its effects on gap junctions. Thus effects of carbenoxolone on network activity cannot be interpreted as resulting from specific block of gap junctions.

scholarly journals A dark quencher genetically encodable voltage indicator (dqGEVI) exhibits high fidelity and speed

2021 ◽  
Vol 118 (6) ◽  
pp. e2020235118
Author(s):  
Therese C. Alich ◽  
Milan Pabst ◽  
Leonie Pothmann ◽  
Bálint Szalontai ◽  
Guido C. Faas ◽  
...  
Keyword(s):  
Large Scale ◽  
Fluorescent Protein ◽  
Single Photon ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Membrane Properties ◽  
Neuronal Membrane ◽  
High Temporal Resolution ◽  
Action Potential Firing ◽  
Green Fluorescent

Voltage sensing with genetically expressed optical probes is highly desirable for large-scale recordings of neuronal activity and detection of localized voltage signals in single neurons. Most genetically encodable voltage indicators (GEVI) have drawbacks including slow response, low fluorescence, or excessive bleaching. Here we present a dark quencher GEVI approach (dqGEVI) using a Förster resonance energy transfer pair between a fluorophore glycosylphosphatidylinositol–enhanced green fluorescent protein (GPI-eGFP) on the outer surface of the neuronal membrane and an azo-benzene dye quencher (D3) that rapidly moves in the membrane driven by voltage. In contrast to previous probes, the sensor has a single photon bleaching time constant of ∼40 min, has a high temporal resolution and fidelity for detecting action potential firing at 100 Hz, resolves membrane de- and hyperpolarizations of a few millivolts, and has negligible effects on passive membrane properties or synaptic events. The dqGEVI approach should be a valuable tool for optical recordings of subcellular or population membrane potential changes in nerve cells.

The distribution of NADPH-diaphorase-labelled interneurons and the role of nitric oxide in the swimming system of Xenopus laevis larvae

2000 ◽  
Vol 203 (4) ◽  
pp. 705-713 ◽  
Author(s):  
D.L. McLean ◽  
K.T. Sillar
Keyword(s):  
Nitric Oxide ◽  
Xenopus Laevis ◽  
Swimming Activity ◽  
Nadph Diaphorase ◽  
Membrane Properties ◽  
Neuronal Membrane ◽  
Cycle Period ◽  
No Donor ◽  
Nos Inhibitors

The possible involvement of the free radical gas nitric oxide (NO) in the modulation of spinal rhythm-generating networks has been studied using Xenopus laevis larvae. Using NADPH-diaphorase histochemistry, three putative populations of nitric oxide synthase (NOS)-containing cells were identified in the brainstem. The position and morphology of the largest and most caudal population suggested that a proportion of these neurons is reticulospinal. The possible contribution of nitrergic neurons to the control of swimming activity was examined by manipulating exogenous and endogenous NO concentrations in vivo with an NO donor (SNAP, 100–500 micromol l(−)(1)) and NOS inhibitors (l-NAME and l-NNA, 0.5-5 mmol l(−)(1)), respectively. In the presence of SNAP, swim episode duration decreased and cycle period increased, whereas the NOS inhibitors had the opposite effects. We conclude from these data that the endogenous release of NO from brainstem neurons extrinsic to the spinal cord of Xenopus laevis larvae exerts a continuous modulatory influence on swimming activity, functioning like a ‘brake’. Although the exact level at which NO impinges upon the swimming rhythm generator has yet to be determined, the predominantly inhibitory effect of NO suggests that the underlying mechanisms of NO action could involve modulation of synaptic transmission and/or direct effects on neuronal membrane properties.

scholarly journals FoxO3 regulates neuronal reprogramming of cells from postnatal and aging mice

2016 ◽  
Vol 113 (30) ◽  
pp. 8514-8519 ◽  
Author(s):  
Henrik Ahlenius ◽  
Soham Chanda ◽  
Ashley E. Webb ◽  
Issa Yousif ◽  
Jesse Karmazin ◽  
...  
Keyword(s):  
Membrane Properties ◽  
Neuronal Membrane ◽  
Embryonic Fibroblasts ◽  
Aged Mice ◽  
Functional Maturation ◽  
Forkhead Box ◽  
Cell Conversion ◽  
Reprogramming Efficiency ◽  
In Cells

We and others have shown that embryonic and neonatal fibroblasts can be directly converted into induced neuronal (iN) cells with mature functional properties. Reprogramming of fibroblasts from adult and aged mice, however, has not yet been explored in detail. The ability to generate fully functional iN cells from aged organisms will be particularly important for in vitro modeling of diseases of old age. Here, we demonstrate production of functional iN cells from fibroblasts that were derived from mice close to the end of their lifespan. iN cells from aged mice had apparently normal active and passive neuronal membrane properties and formed abundant synaptic connections. The reprogramming efficiency gradually decreased with fibroblasts derived from embryonic and neonatal mice, but remained similar for fibroblasts from postnatal mice of all ages. Strikingly, overexpression of a transcription factor, forkhead box O3 (FoxO3), which is implicated in aging, blocked iN cell conversion of embryonic fibroblasts, whereas knockout or knockdown of FoxO3 increased the reprogramming efficiency of adult-derived but not of embryonic fibroblasts and also enhanced functional maturation of resulting iN cells. Hence, FoxO3 has a central role in the neuronal reprogramming susceptibility of cells, and the importance of FoxO3 appears to change during development.

Peptide regulation of neuronal membrane properties

1976 ◽  
Vol 103 (1) ◽  
pp. 167-170 ◽  
Author(s):  
Jeffery L. Barker ◽  
T.G. Smith
Keyword(s):  
Membrane Properties ◽  
Neuronal Membrane

Hyperforin modifies neuronal membrane properties in vivo

2004 ◽  
Vol 367 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Gunter P. Eckert ◽  
Jan-Henning Keller ◽  
Claudia Jourdan ◽  
Michael Karas ◽  
Dietrich A. Volmer ◽  
...  
Keyword(s):  
Membrane Properties ◽  
Neuronal Membrane
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