Cortical spreading depression-induced preconditioning in mouse neocortex is lamina specific

2013 ◽  
Vol 109 (12) ◽  
pp. 2923-2936 ◽  
Author(s):  
Helen M. Gniel ◽  
Rosemary L. Martin
Keyword(s):  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Pyramidal Neurons ◽  
Brain Slices ◽  
Glucose Deprivation ◽  
Time Frame ◽  
Degree Of Protection ◽  
Equilibrative Nucleoside Transporters ◽  
A Cell ◽  
Layer V

Cortical spreading depression (CSD) is able to confer neuroprotection when delivered at least 1 day in advance of an ischemic event. However, its ability to confer neuroprotection in a more immediate time frame has not previously been investigated. Here we have used mouse neocortical brain slices to study the effects of repeated episodes of CSD in layer V and layer II/III pyramidal neurons. In layer V, CSD evoked at 15-min intervals caused successively smaller membrane depolarizations and increases in intracellular calcium compared with the response to the first CSD. With an inter-CSD interval of 30 min this preconditioning effect was much less marked, indicating that preconditioning lasts between 15 and 30 min. A single episode of CSD also provided a degree of protection in oxygen-glucose deprivation (OGD) by significantly lengthening the time a cell could withstand OGD before anoxic depolarization occurred. In layer II/III pyramidal neurons no preconditioning by CSD on subsequent episodes of CSD was observed, demonstrating that the response of pyramidal neurons to repeated CSD is lamina specific. The A1 receptor antagonist 8-cyclopentyl theophylline (8-CPT) reduced the layer V preconditioning in a concentration-related manner. Inhibition of extracellular formation of adenosine by blocking ecto-5′-nucleotidase with α,β-methyleneadenosine 5′-diphosphate prevented preconditioning in most but not all cells. Block of equilibrative nucleoside transporters 1 and 2 with dipyramidole alone or in combination with 6-[(4-nitrobenzyl)thio]-9-β-d-ribofuranosylpurine also prevented preconditioning in some but not all cells. These data provide evidence that rapid preconditioning of one CSD by another is primarily mediated by adenosine.

Changes in Membrane Potential and the Intracellular Calcium Concentration During CSD and OGD in Layer V and Layer II/III Mouse Cortical Neurons

2010 ◽  
Vol 104 (6) ◽  
pp. 3203-3212 ◽  
Author(s):  
Helen M. Gniel ◽  
Rosemary L. Martin
Keyword(s):  
Membrane Potential ◽  
Intracellular Calcium ◽  
Cortical Neurons ◽  
Calcium Concentration ◽  
Pyramidal Neurons ◽  
Brain Slices ◽  
Glucose Deprivation ◽  
Intracellular Calcium Concentration ◽  
Neuronal Types ◽  
Layer V

Cortical spreading depression (CSD) is an episode of electrical silence following intense neuronal activity that propagates across the cortex at ∼3–6 mm/min and is associated with transient neuronal depolarization. CSD is benign in normally perfused brain tissue, but there is evidence suggesting that repetitive CSD contributes to infarct growth following focal ischemia. Studies to date have assumed that the cellular responses to CSD are uniform across neuronal types because there are no data to the contrary. In this study, we investigated the effect of CSD on membrane potential and the intracellular calcium concentration ([Ca2+]i) of mouse layer V and layer II/III pyramidal neurons in brain slices. To place the data in context, we made similar measurements during anoxic depolarization induced by oxygen and glucose deprivation (OGD). The [Ca2+]i was quantified using the low-affinity ratiometric indicator Fura-4F. During both CSD- and OGD-induced depolarization, the membrane potential approached 0 mV in all neurons. In layer V pyramids OGD resulted in an increase in [Ca2+]i to a maximum of 3.69 ± 0.73 (SD) μM ( n = 12), significantly greater than the increase to 1.81 ± 0.70 μM in CSD ( n = 34; P < 0.0001). Membrane potential and [Ca2+]i returned to nearly basal levels following CSD but not OGD. Layer II/III neurons responded to CSD with a greater peak increase in [Ca2+]i than layer V neurons (2.88 ± 0.6 μM; n = 9; P < 0.01). We conclude there is a laminar difference in the response of pyramidal neurons to CSD; possible explanations are discussed.

scholarly journals Maternal immune activation induces methylation changes in schizophrenia genes

2022 ◽  
Author(s):  
Tom Johnson ◽  
Defne Saatci ◽  
Lahiru Handunnetthi
Keyword(s):  
Environmental Risk ◽  
Immune Activation ◽  
Pyramidal Neurons ◽  
Fold Change ◽  
Adult Brain ◽  
Maternal Immune Activation ◽  
Differentially Methylated Genes ◽  
A Cell ◽  
Layer V ◽  
Upregulated Genes

Susceptibility to schizophrenia is mediated by genetic and environmental risk factors. Infection driven maternal immune activation (MIA) during pregnancy is a key environmental risk factor. However, little is known about how MIA during pregnancy could contribute to adult-onset schizophrenia. In this study, we investigated if maternal immune activation induces changes in methylation of genes linked to schizophrenia. We found that differentially expressed genes in schizophrenia brain were significantly enriched among MIA induced differentially methylated genes in the foetal brain in a cell-type-specific manner. Upregulated genes in layer V pyramidal neurons were enriched among hypomethylated genes at gestational day 9 (fold change = 1.57 , FDR = 0.049) and gestational day 17 (fold change = 1.97 , FDR = 0.0006). We also found that downregulated genes in GABAergic Rosehip interneurons were enriched among hypermethylated genes at gestational day 17 (fold change = 1.62, FDR= 0.03). Collectively, our results highlight a connection between MIA driven methylation changes during gestation and schizophrenia gene expression signatures in the adult brain. These findings carry important implications for early preventative strategies in schizophrenia.

scholarly journals Cortical spreading depression in migraine-time to reconsider?

2015 ◽  
Vol 73 (8) ◽  
pp. 714-721 ◽  
Author(s):  
Alan J McComas ◽  
Adrian R M Upton
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Cortical Spreading Depression ◽  
Magnetic Stimulation ◽  
Spreading Depression ◽  
Pyramidal Neurons ◽  
Impulse Activity ◽  
Cortical Pyramidal Neurons ◽  
New Evidence

New evidence concerning the pathophysiology of migraine has come from the results of therapeutic transcranial magnetic stimulation (tTMS). The instantaneous responses to single pulses applied during the aura or headache phase, together with a number of other observations, make it unlikely that cortical spreading depression is involved in migraine. tTMS is considered to act by abolishing abnormal impulse activity in cortical pyramidal neurons and a suggestion is made as to how this activity could arise.

Astrocyte-mediated inflammation in cortical spreading depression

Cephalalgia ◽  
2017 ◽  
Vol 38 (4) ◽  
pp. 626-638 ◽  
Author(s):  
Amir Ghaemi ◽  
Leila Alizadeh ◽  
Shahnaz Babaei ◽  
Maryam Jafarian ◽  
Maryam Khaleghi Ghadiri ◽  
...  
Keyword(s):  
Inflammatory Markers ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Ex Vivo ◽  
Brain Slices ◽  
Cerebrovascular Diseases ◽  
Protein Markers ◽  
Markers Of Inflammation ◽  
Reactive Astrocytosis

Background Cortical spreading depression (CSD) related diseases such as migraine, cerebrovascular diseases, and epilepsy have been associated with reactive astrocytosis, yet the mechanisms of these tissue changes remain unclear. CSD-induced inflammatory response has been proposed to play a role in some neurological disorders and thus may also contribute to reactive astrocytosis. Methods Using ex vivo brain slices and in vitro astrocytic cultures, we aimed to characterize CSD related changes in astrocytes and markers of inflammation by immunocyto- and immunohistochemistry. CSD was induced by application of KCl (3 mol/l) on neocortical tissues. The application of KCl was repeated weekly over the course of four weeks. Results CSD induced an increase in the mean number and volume of astrocytes in rat brain tissue when compared to controls, whereas no changes in neuronal numbers and volumes were seen. These cell-type specific changes, suggestive of reactive astrocytosis, were paralleled by an increased expression of protein markers indicative of astrocytes and neuroinflammation in ex vivo brain slices of animals undergoing CSD when compared to sham-treated controls. Cultured astrocytes showed an increased expression of the immune modulatory enzyme indoleamine 2,3-dioxygenase and an elevated expression of the pro-inflammatory markers, IL-6, IL-1β, and TNFα in addition to increased levels of toll like receptors (TLR3 and TLR4) and astrocytic markers after induction of CSD. Conclusion These findings indicate that CSD related reactive astrocytosis is linked to an upregulation of inflammatory markers. Targeting inflammation with already approved and available immunomodulatory treatments may thus represent a strategy to combat or ameliorate CSD-related disease.

scholarly journals Sarcoma Family Kinase-Dependent Pannexin-1 Activation after Cortical Spreading Depression Is Mediated by NR2A-Containing Receptors

2020 ◽  
Vol 21 (4) ◽  
pp. 1269 ◽  
Author(s):  
Fan Bu ◽  
Lingdi Nie ◽  
John P Quinn ◽  
Minyan Wang
Keyword(s):  
Mouse Brain ◽  
Protein Interactions ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Regulatory Mechanism ◽  
Brain Slices ◽  
Pannexin 1 ◽  
Migraine Headaches ◽  
Aspartate Receptor ◽  
Channel Opening

Cortical spreading depression (CSD) is a propagating wave of depolarization followed by depression of cortical activity. CSD triggers neuroinflammation via the pannexin-1 (Panx1) channel opening, which may eventually cause migraine headaches. However, the regulatory mechanism of Panx1 is unknown. This study investigates whether sarcoma family kinases (SFK) are involved in transmitting CSD-induced Panx1 activation, which is mediated by the NR2A-containing N-methyl-D-aspartate receptor. CSD was induced by topical application of K+ to cerebral cortices of rats and mouse brain slices. SFK inhibitor, PP2, or NR2A–receptor antagonist, NVP–AAM077, was perfused into contralateral cerebral ventricles (i.c.v.) of rats prior to CSD induction. Co-immunoprecipitation and Western blot were used for detecting protein interactions, and histofluorescence for addressing Panx1 activation. The results demonstrated that PP2 attenuated CSD-induced Panx1 activation in rat ipsilateral cortices. Cortical susceptibility to CSD was reduced by PP2 in rats and by TAT-Panx308 that disrupts SFK–Panx1 interaction in mouse brain slices. Furthermore, CSD promoted activated SFK coupling with Panx1 in rat ipsilateral cortices. Moreover, inhibition of NR2A by NVP–AAM077 reduced elevation of ipsilateral SFK–Panx1 interaction, Panx1 activation induced by CSD and cortical susceptibility to CSD in rats. These data suggest NR2A-regulated, SFK-dependent Panx1 activity plays an important role in migraine aura pathogenesis.

High I h Channel Density in the Distal Apical Dendrite of Layer V Pyramidal Cells Increases Bidirectional Attenuation of EPSPs

2001 ◽  
Vol 85 (2) ◽  
pp. 855-868 ◽  
Author(s):  
Thomas Berger ◽  
Matthew E. Larkum ◽  
Hans-R. Lüscher
Keyword(s):  
Temporal Summation ◽  
Pyramidal Neurons ◽  
Brain Slices ◽  
Pyramidal Cells ◽  
Signal Propagation ◽  
Apical Dendrite ◽  
Distal Dendrite ◽  
Channel Density ◽  
Apical Tuft ◽  
Layer V

Despite the wealth of recent research on active signal propagation along the dendrites of layer V neocortical pyramidal neurons, there is still little known regarding the traffic of subthreshold synaptic signals. We present a study using three simultaneous whole cell recordings on the apical dendrites of these cells in acute rat brain slices to examine the spread and attenuation of spontaneous excitatory postsynaptic potentials (sEPSPs). Equal current injections at each of a pair of sites separated by ∼500 μm on the apical dendrite resulted in equal voltage transients at the other site (“reciprocity”), thus disclosing linear behavior of the neuron. The mean apparent “length constants” of the apical dendrite were 273 and 446 μm for somatopetal and somatofugal sEPSPs, respectively. Trains of artificial EPSPs did not show temporal summation. Blockade of the hyperpolarization-activated cation current ( I h) resulted in less attenuation by 17% for somatopetal and by 47% for somatofugal sEPSPs. A pronounced location-dependent temporal summation of EPSP trains was seen. The subcellular distribution and biophysical properties of I h were studied in cell-attached patches. Within less than ∼400 μm of the soma, a low density of ∼3 pA/μm2 was found, which increased to ∼40 pA/μm2 in the apical distal dendrite. I h showed activation and deactivation kinetics with time constants faster than 40 ms and half-maximal activation at −95 mV. These findings suggest that integration of synaptic input to the apical tuft and the basal dendrites occurs spatially independently. This is due to a high I h channel density in the apical tuft that increases the electrotonic distance between these two compartments in comparison to a passive dendrite.

scholarly journals TRPA1-Mediated Src Family Kinases Activity Facilitates Cortical Spreading Depression Susceptibility and Trigeminovascular System Sensitization

2021 ◽  
Vol 22 (22) ◽  
pp. 12273
Author(s):  
Lingdi Nie ◽  
Liwen Jiang ◽  
John P. Quinn ◽  
Blair D. Grubb ◽  
Minyan Wang
Keyword(s):  
Mouse Brain ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Quantitative Polymerase Chain Reaction ◽  
Brain Slices ◽  
Src Family Kinases ◽  
Enzyme Linked Immunosorbent Assay ◽  
Trigeminovascular System ◽  
Cgrp Release ◽  
Migraine Pathogenesis

Transient receptor potential ankyrin 1 (TRPA1) plays a role in migraine and is proposed as a promising target for migraine therapy. However, TRPA1-induced signaling in migraine pathogenesis is poorly understood. In this study, we explored the hypothesis that Src family kinases (SFKs) transmit TRPA1 signaling in regulating cortical spreading depression (CSD), calcitonin gene-related peptide (CGRP) release and neuroinflammation. CSD was monitored in mouse brain slices via intrinsic optical imaging, and in rats using electrophysiology. CGRP level and IL-1β gene expression in mouse trigeminal ganglia (TG) was detected using Enzyme-linked Immunosorbent Assay and Quantitative Polymerase Chain Reaction respectively. The results showed a SFKs activator, pYEEI (EPQY(PO3H2)EEEIPIYL), reversed the reduced cortical susceptibility to CSD by an anti-TRPA1 antibody in mouse brain slices. Additionally, the increased cytosolic phosphorylated SFKs at Y416 induced by CSD in rat ipsilateral cerebral cortices was attenuated by pretreatment of the anti-TRPA1 antibody perfused into contralateral ventricles. In mouse TG, a SFKs inhibitor, saracatinib, restored the CGRP release and IL-1β mRNA level increased by a TRPA1 activator, umbellulone. Moreover, umbellulone promoted SFKs phosphorylation, which was reduced by a PKA inhibitor, PKI (14–22) Amide. These data reveal a novel mechanism of migraine pathogenesis by which TRPA1 transmits signaling to SFKs via PKA facilitating CSD susceptibility and trigeminovascular system sensitization.

scholarly journals Src family kinases activity is required for transmitting purinergic P2X7 receptor signaling in cortical spreading depression and neuroinflammation

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lingdi Nie ◽  
Dongqing Ma ◽  
John P. Quinn ◽  
Minyan Wang
Keyword(s):  
Gene Expression ◽  
Mouse Brain ◽  
P2x7 Receptor ◽  
Cortical Spreading Depression ◽  
Spreading Depression ◽  
Glutamate Release ◽  
Brain Slices ◽  
Src Family Kinases ◽  
Receptor Signaling ◽  
Purinergic P2x7 Receptor

Abstract Background Purinergic P2X7 receptor plays an important role in migraine pathophysiology. Yet precise molecular mechanism underlying P2X7R signaling in migraine remains unclear. This study explores the hypothesis that P2X7 receptor transmits signaling to Src family kinases (SFKs) during cortical spreading depression (CSD) and neuroinflammation after CSD. Methods CSD was recorded using electrophysiology in rats and intrinsic optical imaging in mouse brain slices. Cortical IL-1β and TNFα mRNA levels were detected using qPCR. Glutamate release from mouse brain slices was detected using glutamate assay. Results The data showed that deactivation of SFKs by systemic injection of PP2 reduced cortical susceptibility to CSD in rats and CSD-induced IL-1β and TNF-α gene expression in rat ipsilateral cortices. Consistently, in mouse brain slices, inhibition of SFKs activity by saracatinib and P2X7 receptor by A740003 similarly reduced cortical susceptibility to CSD. When the interaction of P2X7 receptor and SFKs was disrupted by TAT-P2X7, a marked reduction of cortical susceptibility to CSD, IL-1β gene expression and glutamate release after CSD induction were observed in mouse brain slices. The reduced cortical susceptibility to CSD by TAT-P2X7 was restored by NMDA, and disrupting the Fyn-NMDA interaction using TAT-Fyn (39-57) but not disrupting Src-NMDA receptor interaction using TAT-Src (40-49) reduced cortical susceptibility to CSD. Furthermore, activation of P2X7 receptor by BzATP restored the TAT-Fyn (39-57)-reduced cortical susceptibility to CSD. Conclusion This study reveals that SFKs activity transmits P2X7 receptor signaling to facilitate CSD propagation via glutamatergic pathway and promote neuroinflammation, which is of particular relevance to migraine.

OBSERVING NEURONAL ACTIVITIES WITH RANDOM ACCESS TWO-PHOTON MICROSCOPE

2009 ◽  
Vol 02 (01) ◽  
pp. 67-71 ◽  
Author(s):  
YUXIANG WU ◽  
XIULI LIU ◽  
WEI ZHOU ◽  
XIAOHUA LV ◽  
SHAOQUN ZENG
Keyword(s):  
Pyramidal Neurons ◽  
Brain Slices ◽  
Random Access ◽  
Tissue Imaging ◽  
Free Calcium ◽  
Patch Clamp Technique ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Free Calcium Concentration ◽  
Layer V

As a second messenger in signal transduction, calcium ion plays a very important role in neuronal information processing and integrating. Limited by the imaging technique, it is difficult to simultaneously perform deep tissue imaging and measure intracellular free calcium concentration ([ Ca 2+] i ) in different compartments of neurons in brain slice noncollinearly. By means of random access two-photon microscopy, which provides high optical penetration into tissues and low photo damage, we successfully measured [ Ca 2+] i of different parts of pyramidal neurons in neocortical layer V in rat brain slices with high spatial and temporal resolution. Combining the patch clamp technique, we stimulated the soma with depolarizing current and explored the dynamics of calcium in pyramidal neurons.

scholarly journals Baseline Glutamate Levels Affect Group I and II mGluRs in Layer V Pyramidal Neurons of Rat Sensorimotor Cortex

2003 ◽  
Vol 89 (3) ◽  
pp. 1308-1316 ◽  
Author(s):  
A. E. Bandrowski ◽  
J. R. Huguenard ◽  
D. A. Prince
Keyword(s):  
Metabotropic Glutamate Receptors ◽  
Pyramidal Neurons ◽  
Cortical Excitability ◽  
Brain Slices ◽  
Mean Amplitude ◽  
Group Iii ◽  
Metabotropic Glutamate ◽  
Group I ◽  
Group Ii ◽  
Layer V

Possible functional roles for glutamate that is detectable at low concentrations in the extracellular space of intact brain and brain slices have not been explored. To determine whether this endogenous glutamate acts on metabotropic glutamate receptors (mGluRs), we obtained whole cell recordings from layer V pyramidal neurons of rat sensorimotor cortical slices. Blockade of mGluRs with (+)-α-amino-4-carboxy-α-methyl-benzeacetic acid (MCPG, a general mGluR antagonist) increased the mean amplitude of spontaneous excitatory postsynaptic currents (sEPSCs), an effect attributable to a selective increase in the occurrence of large amplitude sEPSCs. 2S-2-amino-2-(1S,2S-2-carboxycyclopropyl-1-yl)-3-(xanth-9-yl)propanoic acid (LY341495, a group II antagonist) increased, but R(−)-1-amino-2,3-dihydro-1H-indene-1,5-dicarboxylic acid (AIDA) and (RS)-hexyl-HIBO (group I antagonists) decreased sEPSC amplitude, and (R,S)-α-cyclopropyl-4-phosphonophenylglycine (CPPG, a group III antagonist) did not change it. The change in sEPSCs elicited by MCPG, AIDA, and LY341495 was absent in tetrodotoxin, suggesting that it was action potential-dependent. The increase in sEPSCs persisted in GABA receptor antagonists, indicating that it was not due to effects on inhibitory interneurons. AIDA and ( S)-3,5-dihydroxyphenylglycine (DHPG, a group I agonist) elicited positive and negative shifts in holding current, respectively. LY341495 and (2S,2′R,3′R)-2-(2′,3′-dicarboxycyclopropyl)glycine (DCG-IV, a group II agonist) elicited negative and positive shifts in holding current, respectively. The AIDA and LY341495 elicited currents persisted in TTX. Finally, in current clamp, LY341495 depolarized cells by ∼2 mV and increased the number of action potentials to a given depolarizing current pulse. Thus ambient levels of glutamate tonically activate mGluRs and regulate cortical excitability.

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