BOLD-fMRI of PTZ-induced seizures in rats

Keogh, Bart P.; Cordes, Dietmar; Stanberry, Larissa; Figler, Bradley D.; Robbins, Carol A.; Tempel, Bruce L.; Green, C. G.; Emmi, Adriana; Maravilla, K R; Schwartzkroin, Philip A.

doi:10.1016/j.eplepsyres.2005.07.008

Cited by 35 publications

(23 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More importantly, pentylenetetrazole exposure elicited brief small amplitude, high frequency ('interictal-like') and complex multispike, large amplitude ('ictal-like') electrographic discharge that could be monitored using a field electrode placed in the zebrafish telencephalon or optic tectum. Pentylenetetrazole-evoked electrical discharges were similar in waveform to those reported in mice or rats injected with this drug [48], and were abolished by valproic acid and benzodiazepines in a concentration-dependent manner.…”

Section: Seizures In Immature Zebrafishsupporting

confidence: 54%

Emerging epilepsy models: insights from mice, flies, worms and fish

Baraban

2007

Current Opinion in Neurology

View full text Add to dashboard Cite

Purpose of review-Animal models provide a means to investigate fundamental mechanisms of abnormal electrical discharge (i.e., seizures). Understanding the pathogenesis of epilepsy and therapy development have greatly benefited from these models. Here we review recent mouse mutants featuring spontaneous seizures and simpler organisms.Recent findings-New genetically engineered mice provide additional insights to cellular mechanisms underlying seizure generation (BK calcium-activated potassium channels and interneuron-expressed sodium channels), genetic interactions that exacerbate seizure phenotype (Scn2a, Kcnq2 and background) and neurodevelopmental influences (Dlx transcription factors). Mutants for neuronal nicotinic acetylcholine receptors, Glut-1 deficiency and aquaporin channels highlight additional seizure phenotypes in mice. Additional models in Caenorhabditis elegans (Lis-1) and Danio rerio (pentylenetetrazole) highlight a reductionist approach. Taking further advantage of 'simple' organisms, antiepileptic drugs and genetic modifiers of seizure activity are being uncovered in Drosophila.Summary-Studies of epilepsy in mutant mice provide a framework for understanding critical features of the brain that regulate excitability. These, and as yet undiscovered, mouse mutants will continue to serve as the foundation for basic epilepsy research. Interestingly, an even greater potential for analyzing epileptic phenotypes may lie in the more widespread use of genetically tractable organisms such as worms, flies and zebrafish.

show abstract

Section: Seizures In Immature Zebrafishsupporting

confidence: 54%

Emerging epilepsy models: insights from mice, flies, worms and fish

Baraban

2007

Current Opinion in Neurology

View full text Add to dashboard Cite

show abstract

“…However, negative BOLD changes were found in the motor cortex as well as in the temporal cortex (3), confirming the previously electrophysiologically verified involvement of somatosensory cortex and thalamus in generation and maintenance of absence seizures (11, 12). After induction of generalized tonic-clonic seizures with pentylenetetrazole (4, 13, 14) or bicuculline (6), fMRI has demonstrated an increase in BOLD signal in the neocortex, amygdala, hippocampal, hypothalamic and thalamic regions suggesting that fMRI could differentiate the network activity even between the different types of generalized seizures.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous fMRI and local field potential measurements during epileptic seizures in medetomidine‐sedated rats using raser pulse sequence

Airaksinen

Niskanen

Chamberlain

et al. 2010

Magnetic Resonance in Med

View full text Add to dashboard Cite

Simultaneous electrophysiological and functional magnetic resonance imaging measurements of animal models of epilepsy are methodologically challenging, but essential to better understand abnormal brain activity and hemodynamics during seizures. In this study, functional magnetic resonance imaging of medetomidine-sedated rats was performed using novel rapid acquisition by sequential excitation and refocusing (RASER) fast imaging pulse sequence and simultaneous local field potential measurements during kainic acid-induced seizures. The image distortion caused by the hippocampal-measuring electrode was clearly seen in echo planar imaging images, whereas no artifact was seen in RASER images. Robust blood oxygenation level-dependent responses were observed in the hippocampus during kainic acid-induced seizures. The recurrent epileptic seizures were detected in the local field potential signal after kainic acid injection. The presented combination of deep electrode local field potential measurements and functional magnetic resonance imaging under medetomidine anesthesia, which does not significantly suppress kainic acidinduced seizures, provides a unique tool for studying abnormal brain activity in rats. Magn Reson Med 64:1191-1199,

show abstract

“…Other types of data-driven techniques such as hierarchical clustering Keogh et al, 2005;Stanberry et al, 2003], fuzzy clustering [Baumgartner et al, 2000], and temporal clustering analysis (TCA) [Gao and Yee, 2003;Liu et al, 2000;Lu et al, 2006;Makiranta et al, 2005;Yee and Gao, 2002;Zhao et al, 2004] use clustering of similar fMRI signal time courses to group and determine voxel time courses of interest, instead of partitioning into components. Previous studies have reported that these clustering algorithms outperform PCA [Baumgartner et al, 2000] and ICA techniques for fMRI analysis [Meyer-Baese et al, 2004].…”

Section: Introductionmentioning

confidence: 99%

Development of 2dTCA for the detection of irregular, transient bold activity

Morgan¹,

Li²,

Abou‐Khalil³

et al. 2007

Human Brain Mapping

View full text Add to dashboard Cite

The temporal clustering algorithm (TCA) has been developed in order to detect irregular, transient functional MRI (fMRI) activation signals when the timings of the stimuli are unknown. Unfortunately, such methods are also sensitive to signal changes caused by motion and physiological noise. We have developed a modified TCA technique, 2dTCA, which can detect multiple different timing patterns within a dataset so that signals of interest can be separated from artifacts and those of no interest. The objective of this work was to further develop the 2dTCA methods and evaluate their performance in simulated functional MRI datasets. Comparisons were made with TCA and a freely-distributed independent component analysis algorithm (ICA). We created two different sets of six computer-generated phantoms with one and two different simulated activation time courses present in 10 regions of interest. The phantoms also contained real subject rigid and nonrigid body motion and noise. Sensitivity of detection, defined as the true-positive activation rate at false-positive activation rates varying between 0.0001 and 0.01, was compared between methods. Additionally, specificity of detection of the irregular, transient signal of interest was assessed by comparing the number of signal time courses detected by each algorithm. The results suggest that the increased sensitivity of 2dTCA over TCA in detecting this particular signal of interest is comparable to the detection with ICA, but with fewer other signals detected. A few examples of the successful application of 2dTCA to the localization of interictal activity in preliminary studies of temporal lobe epilepsy are also described.

show abstract

BOLD-fMRI of PTZ-induced seizures in rats

Cited by 35 publications

References 43 publications

Emerging epilepsy models: insights from mice, flies, worms and fish

Emerging epilepsy models: insights from mice, flies, worms and fish

Simultaneous fMRI and local field potential measurements during epileptic seizures in medetomidine‐sedated rats using raser pulse sequence

Development of 2dTCA for the detection of irregular, transient bold activity

Contact Info

Product

Resources

About