Picosecond Pulse Electrical Field Suppressing Spike Firing in Hippocampal CA1 in Rat In Vivo

2020 ◽  
Vol 41 (8) ◽  
pp. 617-629
Author(s):  
Chengxiang Li ◽  
Shuhui Wang ◽  
Yuanyuan Zhang ◽  
Enzhao Wang ◽  
Chenguo Yao ◽  
...  
Keyword(s):  
Picosecond Pulse ◽  
Electrical Field ◽  
Hippocampal Ca1 ◽  
Pulse Electrical Field ◽  
Spike Firing

Monocytes as Carriers of Magnetic Nanoparticles for Tracking Inflammation in the Epileptic Rat Brain

2019 ◽  
Vol 16 (7) ◽  
pp. 637-644 ◽  
Author(s):  
Hadas Han ◽  
Sara Eyal ◽  
Emma Portnoy ◽  
Aniv Mann ◽  
Miriam Shmuel ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Ex Vivo ◽  
In Vivo Studies ◽  
Nanoparticle Distribution ◽  
Spontaneous Seizures ◽  
Systemic Distribution ◽  
Hippocampal Ca1 ◽  
Pilocarpine Model

Background: Inflammation is a hallmark of epileptogenic brain tissue. Previously, we have shown that inflammation in epilepsy can be delineated using systemically-injected fluorescent and magnetite- laden nanoparticles. Suggested mechanisms included distribution of free nanoparticles across a compromised blood-brain barrier or their transfer by monocytes that infiltrate the epileptic brain. Objective: In the current study, we evaluated monocytes as vehicles that deliver nanoparticles into the epileptic brain. We also assessed the effect of epilepsy on the systemic distribution of nanoparticleloaded monocytes. Methods: The in vitro uptake of 300-nm nanoparticles labeled with magnetite and BODIPY (for optical imaging) was evaluated using rat monocytes and fluorescence detection. For in vivo studies we used the rat lithium-pilocarpine model of temporal lobe epilepsy. In vivo nanoparticle distribution was evaluated using immunohistochemistry. Results: 89% of nanoparticle loading into rat monocytes was accomplished within 8 hours, enabling overnight nanoparticle loading ex vivo. The dose-normalized distribution of nanoparticle-loaded monocytes into the hippocampal CA1 and dentate gyrus of rats with spontaneous seizures was 176-fold and 380-fold higher compared to the free nanoparticles (p<0.05). Seizures were associated with greater nanoparticle accumulation within the liver and the spleen (p<0.05). Conclusion: Nanoparticle-loaded monocytes are attracted to epileptogenic brain tissue and may be used for labeling or targeting it, while significantly reducing the systemic dose of potentially toxic compounds. The effect of seizures on monocyte biodistribution should be further explored to better understand the systemic effects of epilepsy.

scholarly journals Subthreshold electrical stimulation as a low power electrical treatment for stroke rehabilitation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kyungsoo Kim ◽  
Seung-Jun Yoo ◽  
So Yeon Kim ◽  
Taeju Lee ◽  
Sung-Ho Lim ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Energy Consumption ◽  
Functional Recovery ◽  
Stroke Rehabilitation ◽  
Brain Regions ◽  
Implantable Devices ◽  
Rehabilitation Process ◽  
Neural Excitability ◽  
Spike Firing

AbstractAs a promising future treatment for stroke rehabilitation, researchers have developed direct brain stimulation to manipulate the neural excitability. However, there has been less interest in energy consumption and unexpected side effect caused by electrical stimulation to bring functional recovery for stroke rehabilitation. In this study, we propose an engineering approach with subthreshold electrical stimulation (STES) to bring functional recovery. Here, we show a low level of electrical stimulation boosted causal excitation in connected neurons and strengthened the synaptic weight in a simulation study. We found that STES with motor training enhanced functional recovery after stroke in vivo. STES was shown to induce neural reconstruction, indicated by higher neurite expression in the stimulated regions and correlated changes in behavioral performance and neural spike firing pattern during the rehabilitation process. This will reduce the energy consumption of implantable devices and the side effects caused by stimulating unwanted brain regions.

Subthreshold Electrical Stimulation as A Low Power Electrical Treatment for Stroke Rehabilitation

2021 ◽  
Author(s):  
Kyungsoo Kim ◽  
Seung-Jun Yoo ◽  
So Yeun Kim ◽  
Taeju Lee ◽  
Sung-Ho Lim ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Energy Consumption ◽  
Functional Recovery ◽  
Stroke Rehabilitation ◽  
Brain Regions ◽  
Implantable Devices ◽  
Rehabilitation Process ◽  
Neural Excitability ◽  
Spike Firing

Abstract As a promising future treatment for stroke rehabilitation, researchers have developed direct brain stimulation to manipulate the neural excitability. However, there has been less interest in energy consumption and unexpected side effect caused by electrical stimulation to bring functional recovery for stroke rehabilitation. In this study, we propose an engineering approach with subthreshold electrical stimulation (STES) to bring functional recovery. Here, we show a low level of electrical stimulation boosted causal excitation in connected neurons and strengthened the synaptic weight in a simulation study. We found that STES with motor training enhanced functional recovery after stroke in vivo. STES was shown to induce neural reconstruction, indicated by higher neurite expression in the stimulated regions and correlated changes in behavioral performance and neural spike firing pattern during the rehabilitation process. This will reduce the energy consumption of implantable devices and the side effects caused by stimulating unwanted brain regions.

Isoflurane Bidirectionally Modulates the Paired-Pulse Responses in the Rat Hippocampal CA1 Field In Vivo

2007 ◽  
Vol 105 (4) ◽  
pp. 1006-1011 ◽  
Author(s):  
Kaori Tachibana ◽  
Koichi Takita ◽  
Toshikazu Hashimoto ◽  
Machiko Matsumoto ◽  
Mitsuhiro Yoshioka ◽  
...  
Keyword(s):  
Paired Pulse ◽  
Hippocampal Ca1 ◽  
Hippocampal Ca1 Field

Intrinsic Theta-Frequency Membrane Potential Oscillations in Hippocampal CA1 Interneurons of Stratum Lacunosum-Moleculare

1999 ◽  
Vol 81 (3) ◽  
pp. 1296-1307 ◽  
Author(s):  
C. Andrew Chapman ◽  
Jean-Claude Lacaille
Keyword(s):  
Membrane Potential ◽  
Hippocampal Slices ◽  
Stratum Radiatum ◽  
Potential Oscillations ◽  
Spike Threshold ◽  
Hippocampal Ca1 ◽  
Theta Frequency ◽  
Stratum Lacunosum Moleculare ◽  
Membrane Potential Oscillations

Intrinsic theta-frequency membrane potential oscillations in hippocampal CA1 interneurons of stratum lacunosum-moleculare. The ionic conductances underlying membrane potential oscillations of hippocampal CA1 interneurons located near the border between stratum lacunosum-moleculare and stratum radiatum (LM) were investigated using whole cell current-clamp recordings in rat hippocampal slices. At 22°C, when LM cells were depolarized near spike threshold by current injection, 91% of cells displayed 2–5 Hz oscillations in membrane potential, which caused rhythmic firing. At 32°C, mean oscillation frequency increased to 7.1 Hz. Oscillations were voltage dependent and were eliminated by hyperpolarizing cells 6–10 mV below spike threshold. Blockade of ionotropic glutamate and GABA synaptic transmission did not affect oscillations, indicating that they were not synaptically driven. Oscillations were eliminated by tetrodotoxin, suggesting that Na+ currents generate the depolarizing phase of oscillations. Oscillations were not affected by blocking Ca2+ currents with Cd2+ or Ca2+-free ACSF or by blocking the hyperpolarization-activated current ( I h) with Cs+. Both Ba2+ and a low concentration of 4-aminopyridine (4-AP) reduced oscillations but TEA did not. Theta-frequency oscillations were much less common in interneurons located in stratum oriens. Intrinsic membrane potential oscillations in LM cells of the CA1 region thus involve an interplay between inward Na+ currents and outward K+ currents sensitive to Ba2+ and 4-AP. These oscillations may participate in rhythmic inhibition and synchronization of pyramidal neurons during theta activity in vivo.

scholarly journals Widely Different Correlation Patterns Between Pairs of Adjacent Thalamic Neurons In vivo

2021 ◽  
Vol 15 ◽  
Author(s):  
Anders Wahlbom ◽  
Hannes Mogensen ◽  
Henrik Jörntell
Keyword(s):  
Cortical Neurons ◽  
Pyramidal Neurons ◽  
Thalamic Nuclei ◽  
Thalamic Neurons ◽  
Low Weight ◽  
Afferent Inputs ◽  
Cortical Inputs ◽  
Unique Relationship ◽  
Spike Firing

We have previously reported different spike firing correlation patterns among pairs of adjacent pyramidal neurons within the same layer of S1 cortex in vivo, which was argued to suggest that acquired synaptic weight modifications would tend to differentiate adjacent cortical neurons despite them having access to near-identical afferent inputs. Here we made simultaneous single-electrode loose patch-clamp recordings from 14 pairs of adjacent neurons in the lateral thalamus of the ketamine-xylazine anesthetized rat in vivo to study the correlation patterns in their spike firing. As the synapses on thalamic neurons are dominated by a high number of low weight cortical inputs, which would be expected to be shared for two adjacent neurons, and as far as thalamic neurons have homogenous membrane physiology and spike generation, they would be expected to have overall similar spike firing and therefore also correlation patterns. However, we find that across a variety of thalamic nuclei the correlation patterns between pairs of adjacent thalamic neurons vary widely. The findings suggest that the connectivity and cellular physiology of the thalamocortical circuitry, in contrast to what would be expected from a straightforward interpretation of corticothalamic maps and uniform intrinsic cellular neurophysiology, has been shaped by learning to the extent that each pair of thalamic neuron has a unique relationship in their spike firing activity.

scholarly journals Astrocyte-secreted IL-33 mediates homeostatic synaptic plasticity in the adult hippocampus

2020 ◽  
Vol 118 (1) ◽  
pp. e2020810118
Author(s):  
Ye Wang ◽  
Wing-Yu Fu ◽  
Kit Cheung ◽  
Kwok-Wang Hung ◽  
Congping Chen ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Neuronal Activity ◽  
Hippocampal Slices ◽  
Memory Formation ◽  
Conditional Knockout ◽  
Acute Administration ◽  
Excitatory Synapses ◽  
Homeostatic Synaptic Plasticity ◽  
Hippocampal Ca1

Hippocampal synaptic plasticity is important for learning and memory formation. Homeostatic synaptic plasticity is a specific form of synaptic plasticity that is induced upon prolonged changes in neuronal activity to maintain network homeostasis. While astrocytes are important regulators of synaptic transmission and plasticity, it is largely unclear how they interact with neurons to regulate synaptic plasticity at the circuit level. Here, we show that neuronal activity blockade selectively increases the expression and secretion of IL-33 (interleukin-33) by astrocytes in the hippocampal cornu ammonis 1 (CA1) subregion. This IL-33 stimulates an increase in excitatory synapses and neurotransmission through the activation of neuronal IL-33 receptor complex and synaptic recruitment of the scaffold protein PSD-95. We found that acute administration of tetrodotoxin in hippocampal slices or inhibition of hippocampal CA1 excitatory neurons by optogenetic manipulation increases IL-33 expression in CA1 astrocytes. Furthermore, IL-33 administration in vivo promotes the formation of functional excitatory synapses in hippocampal CA1 neurons, whereas conditional knockout of IL-33 in CA1 astrocytes decreases the number of excitatory synapses therein. Importantly, blockade of IL-33 and its receptor signaling in vivo by intracerebroventricular administration of its decoy receptor inhibits homeostatic synaptic plasticity in CA1 pyramidal neurons and impairs spatial memory formation in mice. These results collectively reveal an important role of astrocytic IL-33 in mediating the negative-feedback signaling mechanism in homeostatic synaptic plasticity, providing insights into how astrocytes maintain hippocampal network homeostasis.

Release of epithelium-derived PGE2 from canine trachea after antigen inhalation

1998 ◽  
Vol 274 (2) ◽  
pp. L220-L225 ◽  
Author(s):  
I. McGrogan ◽  
L. J. Janssen ◽  
J. Wattie ◽  
P. M. O’Byrne ◽  
E. E. Daniel
Keyword(s):  
Smooth Muscle ◽  
Electrical Field Stimulation ◽  
Tracheal Smooth Muscle ◽  
Organ Bath ◽  
Field Stimulation ◽  
Electrical Field ◽  
Concentration Response Curve

To investigate the role of prostaglandin (PG) E2 in allergen-induced hyperresponsiveness, dogs inhaled either the allergen Ascaris suum or vehicle (Sham). Twenty-four hours after inhalation, some animals exposed to allergen demonstrated an increased responsiveness to acetylcholine challenge in vivo (Hyp-Resp), whereas others did not (Non-Resp). Strips of tracheal smooth muscle, either epithelium intact or epithelium denuded, were suspended on stimulating electrodes, and a concentration-response curve to carbachol (10−9 to 10−5 M) was generated. Tissues received electrical field stimulation, and organ bath fluid was collected to determine PGE2content. With the epithelium present, all three groups contracted similarly to 10−5 M carbachol, whereas epithelium-denuded tissues from animals that inhaled allergen contracted more than tissues from Sham dogs. In response to electrical field stimulation, Hyp-Resp tissues contracted less than Sham tissues in the presence of epithelium and more than Sham tissues in the absence of epithelium. PGE2release in the muscle bath was greater in Non-Resp tissues than in Sham or Hyp-Resp tissues when the epithelium was present. Removal of the epithelium greatly inhibited PGE2release. We conclude that tracheal smooth muscle is hyperresponsive in vitro after in vivo allergen exposure only when the modulatory effect of the epithelium, largely through PGE2 release, is removed.

Hippocampus Retains the Periodicity of Gamma Stimulation In Vivo

2002 ◽  
Vol 88 (5) ◽  
pp. 2349-2354 ◽  
Author(s):  
J. E. Mikkonen ◽  
T. Grönfors ◽  
J. J. Chrobak ◽  
M. Penttonen
Keyword(s):  
Information Acquisition ◽  
Pyramidal Cells ◽  
Gamma Oscillations ◽  
Short Term ◽  
Ca1 Pyramidal Cells ◽  
State Dependent ◽  
Hippocampal Ca1 ◽  
Oscillatory Rhythms ◽  
The Brain

Several behavioral state dependent oscillatory rhythms have been identified in the brain. Of these neuronal rhythms, gamma (20–70 Hz) oscillations are prominent in the activated brain and are associated with various behavioral functions ranging from sensory binding to memory. Hippocampal gamma oscillations represent a widely studied band of frequencies co-occurring with information acquisition. However, induction of specific gamma frequencies within the hippocampal neuronal network has not been satisfactorily established. Using both in vivo intracellular and extracellular recordings from anesthetized rats, we show that hippocampal CA1 pyramidal cells can discharge at frequencies determined by the preceding gamma stimulation, provided that the gamma is introduced in theta cycles, as occurs in vivo. The dynamic short-term alterations in the oscillatory discharge described in this paper may serve as a coding mechanism in cortical neuronal networks.

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