Patch-clamp analysis of membrane properties of bursting neurons in the young adult rat ventral horn in vitro

2007 ◽  
Vol 58 ◽  
pp. S211
Author(s):  
Ryoko Hisamitsu ◽  
Hidemasa Furue ◽  
Megumu Yoshimura
Keyword(s):  
Young Adult ◽  
Patch Clamp ◽  
Ventral Horn ◽  
Membrane Properties ◽  
Adult Rat ◽  
Bursting Neurons

scholarly journals A sodium afterdepolarization in rat superior colliculus neurons and its contribution to population activity

2016 ◽  
Vol 116 (1) ◽  
pp. 191-200 ◽  
Author(s):  
Nima Ghitani ◽  
Peter O. Bayguinov ◽  
Michele A. Basso ◽  
Meyer B. Jackson
Keyword(s):  
Decision Making ◽  
Patch Clamp ◽  
Superior Colliculus ◽  
Sudden Onset ◽  
Membrane Properties ◽  
Persistent Activity ◽  
Population Activity ◽  
Lower Amplitude ◽  
Superior Colliculus Neurons

The mammalian superior colliculus (SC) is a midbrain structure that integrates multimodal sensory inputs and computes commands to initiate rapid eye movements. SC neurons burst with the sudden onset of a visual stimulus, followed by persistent activity that may underlie shifts of attention and decision making. Experiments in vitro suggest that circuit reverberations play a role in the burst activity in the SC, but the origin of persistent activity is unclear. In the present study we characterized an afterdepolarization (ADP) that follows action potentials in slices of rat SC. Population responses seen with voltage-sensitive dye imaging consisted of rapid spikes followed immediately by a second distinct depolarization of lower amplitude and longer duration. Patch-clamp recordings showed qualitatively similar behavior: in nearly all neurons throughout the SC, rapid spikes were followed by an ADP. Ionic and pharmacological manipulations along with experiments with current and voltage steps indicated that the ADP of SC neurons arises from Na+ current that either persists or resurges following Na+ channel inactivation at the end of an action potential. Comparisons of pharmacological properties and frequency dependence revealed a clear parallel between patch-clamp recordings and voltage imaging experiments, indicating a common underlying membrane mechanism for the ADP in both single neurons and populations. The ADP can initiate repetitive spiking at intervals consistent with the frequency of persistent activity in the SC. These results indicate that SC neurons have intrinsic membrane properties that can contribute to electrical activity that underlies shifts of attention and decision making.

scholarly journals Windup of Nociceptive Flexion Reflex Depends on Synaptic and Intrinsic Properties of Dorsal Horn Neurons in Adult Rat

2019 ◽  
Author(s):  
Franck Aby ◽  
Rabia Bouali-Benazzouz ◽  
Marc Landry ◽  
Pascal Fossat
Keyword(s):  
Spinal Cord ◽  
Progressive Increase ◽  
Ventral Horn ◽  
Intrinsic Properties ◽  
Calcium Dependent ◽  
Adult Rat ◽  
Dorsal Horn Neurons ◽  
Nociceptive Flexion Reflex

Windup, a progressive increase in spinal response to repetitive stimulations of nociceptive peripheral fibres, is a useful model to study central sensitization to pain. Windup is expressed by neurons in of both dorsal and ventral horn of the spinal cord. In juvenile rats, it has been demonstrated both in vivo and in vitro that windup depends on calcium-dependent intrinsic properties and their modulation by synaptic components. However, the involvement of these two components in the adult remain controversial. In the present study, by means of electromyographic and extracellular recordings, we show that windup in adult, in vivo, depends on a synaptic balance between excitatory NMDA receptors and inhibitory glycinergic receptors. We also demonstrate the involvement of L-type calcium channels in both the dorsal and ventral horn of the spinal cord. These results indicate that windup in adults is similar to juveniles rats and that windup properties are the same regardless spinal network, i.e. sensory or motor.

Changes in Intrinsic Properties of Pyramidal Neurons in Adult Rat S1 During Cortical Reorganization

2005 ◽  
Vol 94 (1) ◽  
pp. 501-511 ◽  
Author(s):  
Peter W. Hickmott
Keyword(s):  
Somatosensory Cortex ◽  
Pyramidal Neurons ◽  
Cortical Reorganization ◽  
Primary Somatosensory Cortex ◽  
Membrane Properties ◽  
Intrinsic Properties ◽  
Adult Rat ◽  
Layer 2 ◽  
Cortical Circuit

Peripheral denervation causes significant changes in the organization of developing or adult primary somatosensory cortex (S1). However, the basic mechanisms that underlie reorganization are not well understood. Most attention has been focused on possible synaptic mechanisms associated with reorganization. However, another important determinant of cortical circuit function is the intrinsic membrane properties of neurons in the circuit. Here we document changes in the intrinsic properties of pyramidal neurons in cortical layer 2/3 in adult rat primary somatosensory cortex (S1) after varying durations of forepaw denervation. Denervation of the forepaw induced a rapid and sustained shift in the location of the border between the forepaw and lower jaw representations of adult S1 (reorganization). Coronal slices from the reorganized region were maintained in vitro and the intrinsic properties of layer 2/3 pyramidal neurons of S1 were determined using whole cell recordings. In general, passive membrane properties were not affected by denervation; however, a variety of active properties were. The most robust changes were increases in the amplitudes of the fast and medium afterhyperpolarization (AHP) and an increase in the interval between action potentials (APs). Additional changes at some durations of denervation were observed for the AP threshold. These observations indicate that changes in intrinsic properties, mostly reflecting a decrease in overall excitation, may play a role in changes in cortical circuit properties during reorganization in adult S1, and suggest a possible role for AHPs in some of those changes.

scholarly journals Olfactory ensheathing cells from the nasal mucosa and olfactory bulb have distinct membrane properties

2019 ◽  
Author(s):  
Katie E. Smith ◽  
Katherine Whitcroft ◽  
Stuart Law ◽  
Peter Andrews ◽  
David Choi ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Membrane Properties ◽  
Olfactory Ensheathing Cells ◽  
List Type ◽  
Molecular Physiology ◽  
Adult Rat ◽  
Axonal Regrowth ◽  
Ensheathing Cells ◽  
Inward Currents

AbstractTransplantation of Olfactory Ensheathing Cells (OECs) is a potential therapy for the regeneration of damaged neurons. While they maintain tissue homeostasis in the olfactory mucosa (OM) and olfactory bulb (OB), their regenerative properties also support the normal sense of smell by enabling continual turnover and axonal regrowth of olfactory sensory neurons (OSNs). However, the molecular physiology of OECs is not fully understood, especially that of OECs from the mucosa. Here, we carried out whole-cell patch clamp recordings from individual OECs cultured from the OM and OB of the adult rat, and from the human OM. A subset of OECs from the rat OM cultured 1-3 days in vitro (DIV) had large weakly rectifying K+ currents, which were sensitive to Ba2+ and desipramine, blockers of Kir4-family channels. Kir4.1 immunofluorescence was detectable in OM cells co-labelled for the OEC marker S100, and found adjacent to axons of OSNs. OECs cultured from rat OB had distinct properties though, displaying strongly rectifying inward currents at hyperpolarized membrane potentials and strongly rectifying outward currents at depolarized potentials. Kir4.1 immunofluorescence was not evident in OECs adjacent to axons of OSNs in the OB. A subset of human OECs cultured from the OM of adults had membrane properties comparable to those of the rat OM, i.e. dominated by Ba2+-sensitive weak inwardly rectifying currents. The membrane properties of peripheral OECs are different to those in central OECs, suggesting they may play distinct roles during olfaction.Table of Contents ImageMain pointsPeripheral and central OECs are functionally distinctPeripheral OECs have large weak inward rectifier currentsCentral OECs have strong inward and outward rectifier currents

Immunoenzymatic demonstration of the simultaneous presence of transferrin, hemopexin and albumin in a same hepatocyte and their ultrastructural localization

1978 ◽  
Vol 36 (2) ◽  
pp. 88-89
Author(s):  
M. Kraemer ◽  
J. Foucrier ◽  
J. Vassy ◽  
M.T. Chalumeau
Keyword(s):  
Plasma Proteins ◽  
Rat Hepatocytes ◽  
Ultrastructural Localization ◽  
Carrier Proteins ◽  
Normal Cells ◽  
Adult Rat ◽  
Adult Rat Hepatocytes ◽  
Monospecific Antisera ◽  
Different Levels

Some authors using immunofluorescent techniques had already suggested that some hepatocytes are able to synthetize several plasma proteins. In vitro studies on normal cells or on cells issued of murine hepatomas raise the same conclusion. These works could be indications of an hepatocyte functionnal non-specialization, meanwhile the authors never give direct topographic proofs suitable with this hypothesis.The use of immunoenzymatic techniques after obtention of monospecific antisera had seemed to us useful to bring forward a better knowledge of this problem. We have studied three carrier proteins (transferrin = Tf, hemopexin = Hx, albumin = Alb) operating at different levels in iron metabolism by demonstrating and localizing the adult rat hepatocytes involved in their synthesis.Immunological, histological and ultrastructural methods have been described in a previous work.

scholarly journals Synthesis and Evaluation of Novel α-Aminoamides Containing Benzoheterocyclic Moiety for the Treatment of Pain

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1716
Author(s):  
Kun Tong ◽  
Ruotian Zhang ◽  
Fengzhi Ren ◽  
Tao Zhang ◽  
Junlin He ◽  
...  
Keyword(s):  
Ion Channels ◽  
Patch Clamp ◽  
Formalin Test ◽  
Sodium Ion ◽  
Inhibitory Potency ◽  
Voltage Gated ◽  
Patch Clamp Electrophysiology ◽  
Sodium Ion Channels

Novel α-aminoamide derivatives containing different benzoheterocyclics moiety were synthesized and evaluated as voltage-gated sodium ion channels blocks the treatment of pain. Compounds 6a, 6e, and 6f containing the benzofuran group displayed more potent in vivo analgesic activity than ralfinamide in both the formalin test and the writhing assay. Interestingly, they also exhibited potent in vitro anti-Nav1.7 and anti-Nav1.8 activity in the patch-clamp electrophysiology assay. Therefore, compounds 6a, 6e, and 6f, which have inhibitory potency for two pain-related Nav targets, could serve as new leads for the development of analgesic medicines.

scholarly journals Exendin-4 Promotes Schwann Cell Survival/Migration and Myelination In Vitro

2021 ◽  
Vol 22 (6) ◽  
pp. 2971
Author(s):  
Shizuka Takaku ◽  
Masami Tsukamoto ◽  
Naoko Niimi ◽  
Hideji Yako ◽  
Kazunori Sango
Keyword(s):  
Phosphatidyl Inositol ◽  
Specific Protein ◽  
Myelin Protein ◽  
Drg Neurons ◽  
Antibody Treatment ◽  
Pi3k Inhibitor Ly294002 ◽  
Adult Rat ◽  
Drg Neuron ◽  
Peripheral Nerve Lesions

Besides its insulinotropic actions on pancreatic β cells, neuroprotective activities of glucagon-like peptide-1 (GLP-1) have attracted attention. The efficacy of a GLP-1 receptor (GLP-1R) agonist exendin-4 (Ex-4) for functional repair after sciatic nerve injury and amelioration of diabetic peripheral neuropathy (DPN) has been reported; however, the underlying mechanisms remain unclear. In this study, the bioactivities of Ex-4 on immortalized adult rat Schwann cells IFRS1 and adult rat dorsal root ganglion (DRG) neuron–IFRS1 co-culture system were investigated. Localization of GLP-1R in both DRG neurons and IFRS1 cells were confirmed using knockout-validated monoclonal Mab7F38 antibody. Treatment with 100 nM Ex-4 significantly enhanced survival/proliferation and migration of IFRS1 cells, as well as stimulated the movement of IFRS1 cells toward neurites emerging from DRG neuron cell bodies in the co-culture with the upregulation of myelin protein 22 and myelin protein zero. Because Ex-4 induced phosphorylation of serine/threonine-specific protein kinase AKT in these cells and its effects on DRG neurons and IFRS1 cells were attenuated by phosphatidyl inositol-3′-phosphate-kinase (PI3K) inhibitor LY294002, Ex-4 might act on both cells to activate PI3K/AKT signaling pathway, thereby promoting myelination in the co-culture. These findings imply the potential efficacy of Ex-4 toward DPN and other peripheral nerve lesions.

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