Interpretation of Intrinsic Optical Signals and Calcein Fluorescence during Acute Excitotoxic Insult in the Hippocampal Slice

Jarvis, Cathryn R.; Lilge, Lothar; Vipond, Gregory J.; Andrew, R. David

doi:10.1006/nimg.1999.0473

Cited by 55 publications

(53 citation statements)

References 46 publications

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“…A similar morphology has been observed with brain slices during glutamate-induced excitotoxicity (Jarvis et al, 1999). The cytoskeleton appears to be quite resilient in vivo, because reperfusion is associated with a remarkable reversal of swollen spines and their dendrites toward normal structure, consistent with work done in vitro (Hasbani et al, 2001;Kirov et al, 2004).…”

Section: Discussionsupporting

confidence: 77%

Rapid Reversible Changes in Dendritic Spine StructureIn VivoGated by the Degree of Ischemia

Zhang¹,

Boyd²,

Delaney³

et al. 2005

J. Neurosci.

248

255

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Current therapeutic windows for effective application of thrombolytic agents are within 3-6 h of stroke. Although treatment can improve outcome, it is unclear what happens to synaptic fine structure during this critical period in vivo. The relationship between microcirculation and dendritic spine structure was determined in mouse somatosensory neurons during stroke. Spines were, on average, 13 m from a capillary and were supplied by ϳ100 red blood cells per second. Moderate ischemia (ϳ50% supply) did not significantly affect spines within 5 h; however, severe ischemia (Ͻ10% supply) caused a rapid loss of spine and dendrite structure within as little as 10 min. Surprisingly, if reperfusion occurred within 20 -60 min, dendrite and spine structure was mostly restored. These data suggest that the basic dendritic wiring diagram remains mostly intact during moderate ischemia and that affected synapses could potentially contribute to functional recovery. With severe ischemia, markedly deformed dendritic structure can partially recover if reperfusion occurs early.

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Section: Discussionsupporting

confidence: 77%

Rapid Reversible Changes in Dendritic Spine StructureIn VivoGated by the Degree of Ischemia

Zhang¹,

Boyd²,

Delaney³

et al. 2005

J. Neurosci.

248

255

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“…In order to further investigate the functional characteristics of altered CA3 networks in pilocarpine-treated rats, we have used here imaging techniques to analyze the activation of the hippocampal formation of rats presenting with recurrent seizures. In particular, we studied hippocampal-EC slices employing intrinsic optical signal (IOS) imaging that provides information on the spatiotemporal patterns of neuronal activity (MacVicar and Hochman, 1991;Andrew et al, 1996;Jarvis et al, 1999;Weissinger et al, 2005) and thus can be used to monitor the onset and propagation of epileptiform synchronization (D'Arcangelo et al, 2001(D'Arcangelo et al, , 2005. In addition, taking advantage of FosB/∆FosB-related protein induction in neurons participating to seizures (Morris et al, 2000;Mohapel et al, 2001), we compared the in vitro findings with the ex vivo patterns of network activity identified in pilocarpine-treated epileptic rats.…”

mentioning

confidence: 99%

Impaired Activation of CA3 Pyramidal Neurons in the Epileptic Hippocampus

Biagini

D’Arcangelo

Baldelli

et al. 2005

NMM

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We employed in vitro and ex vivo imaging tools to characterize the function of limbic neuron networks in pilocarpine-treated and age-matched, nonepileptic control (NEC) rats. Pilocarpinetreated animals represent an established model of mesial temporal lobe epilepsy. Intrinsic optical signal (IOS) analysis of hippocampal-entorhinal cortex (EC) slices obtained from epileptic rats 3 wk after pilocarpine-induced status epilepticus (SE) revealed hyperexcitability in many limbic areas, but not in CA3 and medial EC layer III. By visualizing immunopositivity for FosB/∆FosB-related proteins-which accumulate in the nuclei of neurons activated by seizures-we found that: (1) 24 h after SE, FosB/∆FosB immunoreactivity was absent in medial EC layer III, but abundant in dentate gyrus, hippocampus proper (including CA3) and subiculum; (2) FosB/∆FosB levels progressively diminished 3 and 7 d after SE, whereas remaining elevated (p < 0.01) in subiculum; (3) FosB/∆FosB levels sharply increased 2 wk after SE (and remained elevated up to 3 wk) in dentate gyrus and in most of the other areas but not in CA3. A conspicuous neuronal damage was noticed in medial EC layer III, whereas hippocampus was more preserved. IOS analysis of the stimulusinduced responses in slices 3 wk after SE demonstrated that IOSs in CA3 were lower (p < 0.05) than in NEC slices following dentate gyrus stimulation, but not when stimuli were delivered in CA3. These findings indicate that CA3 networks are hypoactive in comparision with other epileptic limbic areas. We propose that this feature may affect the ability of hippocampal outputs to control epileptiform synchronization in EC.

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“…44 The necklace-like structure of a large amount of dendritic processes is highly efficient at scattering light, such that bead formation over several minutes reduces the transmitted light intensity. [46][47][48] Since the method relying on diffusing reflection integrates all information along the depth direction, the method does not have depth resolution. The depth and diameter of blood vessels usually differ among samples and may change due to the age of the rat.…”

Section: Measured Predictedmentioning

confidence: 99%

Multispectral imaging of absorption and scattering properties ofin vivoexposed rat brain using a digital red-green-blue camera

et al. 2015

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Abstract. In order to estimate multispectral images of the absorption and scattering properties in the cerebral cortex of in vivo rat brain, we investigated spectral reflectance images estimated by the Wiener estimation method using a digital RGB camera. A Monte Carlo simulation-based multiple regression analysis for the corresponding spectral absorbance images at nine wavelengths (500, 520, 540, 560, 570, 580, 600, 730, and 760 nm) was then used to specify the absorption and scattering parameters of brain tissue. In this analysis, the concentrations of oxygenated hemoglobin and that of deoxygenated hemoglobin were estimated as the absorption parameters, whereas the coefficient a and the exponent b of the reduced scattering coefficient spectrum approximated by a power law function were estimated as the scattering parameters. The spectra of absorption and reduced scattering coefficients were reconstructed from the absorption and scattering parameters, and the spectral images of absorption and reduced scattering coefficients were then estimated. In order to confirm the feasibility of this method, we performed in vivo experiments on exposed rat brain. The estimated images of the absorption coefficients were dominated by the spectral characteristics of hemoglobin. The estimated spectral images of the reduced scattering coefficients had a broad scattering spectrum, exhibiting a larger magnitude at shorter wavelengths, corresponding to the typical spectrum of brain tissue published in the literature. The changes in the estimated absorption and scattering parameters during normoxia, hyperoxia, and anoxia indicate the potential applicability of the method by which to evaluate the pathophysiological conditions of in vivo brain due to the loss of tissue viability. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Interpretation of Intrinsic Optical Signals and Calcein Fluorescence during Acute Excitotoxic Insult in the Hippocampal Slice

Cited by 55 publications

References 46 publications

Rapid Reversible Changes in Dendritic Spine StructureIn VivoGated by the Degree of Ischemia

Rapid Reversible Changes in Dendritic Spine StructureIn VivoGated by the Degree of Ischemia

Impaired Activation of CA3 Pyramidal Neurons in the Epileptic Hippocampus

Multispectral imaging of absorption and scattering properties ofin vivoexposed rat brain using a digital red-green-blue camera

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