Reduced hippocampal manganese-enhanced MRI (MEMRI) signal during pilocarpine-induced status epilepticus: Edema or apoptosis?

Malheiros, Jackeline Moraes; Persike, Daniele Suzete; Castro, L.; Sanches, Talita Rojas; Andrade, Lúcia; Tannús, Alberto; Covolan, Luciene

doi:10.1016/j.eplepsyres.2014.02.007

Cited by 20 publications

(24 citation statements)

References 37 publications

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“…Intracerebroventricular administration of TGN-020, at a dose of 100 µg, caused significant decrease in mean spike frequency of penicillin-induced epileptiform activity in rat. This finding is in-line with the previous reports on the high expression of AQP-4 in the brain tissue of epileptic rats (35,36). Song and co-workers (2015) showed that AQP-4 had the high expression in the brain tissue of lithium chloride-pilocarpine epileptic model of rats.…”

Section: Medical Science and Discovery 2018; 5(8):303-11supporting

confidence: 92%

“…Song and co-workers (2015) showed that AQP-4 had the high expression in the brain tissue of lithium chloride-pilocarpine epileptic model of rats. Likewise, in another study it was found that AQP-4 expression was higher in 30 minutes of pilocarpine-induced status epilepticus group in comparison with control (35).…”

Section: Medical Science and Discovery 2018; 5(8):303-11mentioning

confidence: 78%

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The effects of TGN-020 on penicillin induced epileptiform activity in rats

Akyüz

Pala

Kozan

et al. 2018

Medical Science and Discovery

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Recently, various chemical structures were defined as AQP-4 water channel inhibitors including 2-nicotinamide-1,3,4-thiadiazole (TGN-020) (8). In vitro studies indicated that TGN-020 was found the most powerful inhibitor of AQP-4 water channel (9). Pretreatment with TGN-020 significantly reduced brain edema in a mouse model of focal cerebral ischemia using 7.0-T magnetic resonance imaging (MRI) (10). Through increasing the osmolarity of extracellular space, water moves into the cell and ionic edema occurs (11). Therefore, AQP-4 inhibition is a new approach to reduce the cerebral edema and is shown to be promising for the development of effective drugs in the clinical treatment (10). Same as in cerebral edema brain excitability is highly sensitive to acute changes in osmolarity (12). Altering the osmolality of the extracellular fluid changed the amplitude and duration of the epileptiform bursts activity in rat dentate gyrus (13). According to this study decreasing the osmolality increased the amplitude of the spikes within the burst and increasing the osmolality decreased the amplitude in the rat hippocampal slices (14).

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Section: Medical Science and Discovery 2018; 5(8):303-11supporting

confidence: 92%

Section: Medical Science and Discovery 2018; 5(8):303-11mentioning

confidence: 78%

The effects of TGN-020 on penicillin induced epileptiform activity in rats

Akyüz

Pala

Kozan

et al. 2018

Medical Science and Discovery

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“…Accordingly, a similar SE duration has been shown to cause more extensive hippocampal cell damage in the PILO than in the KA model (6), which may lead to an increase in the T 2 relaxation time in the PILO group 3 months after SE. Although this explanation is not conclusive, as no correlation has been established between T 2 HP changes and cell loss, the expression of aquaporin 4, and T 2 relaxation time are increased in the hippocampal region after pilocarpine-induced status (17) and in sclerotic hippocampus in human TLE (48). Other factors, as astrogliosis may contribute to T 2 HP changes and should be addressed in future studies, as recently reported in patients with mesial temporal epilepsy (49).…”

Section: Discussionmentioning

confidence: 99%

“…Animals in the KA and PILO groups developed SE on average 90 and 30 min after the injections, respectively. SE was defined as a state of continuous seizures lasting longer than 5 min (17, 18). To reduce the associated mortality rate and to balance the length of SE, a single dose of thionembutal (25 mg/kg, i.p., Cristalia, Sao Paulo, Brazil) was given to all animals 90 min following SE onset.…”

Section: Methodsmentioning

confidence: 99%

Changes in Hippocampal Volume are Correlated with Cell Loss but Not with Seizure Frequency in Two Chronic Models of Temporal Lobe Epilepsy

et al. 2014

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Kainic acid (KA) or pilocarpine (PILO) have been used in rats to model human temporal lobe epilepsy (TLE) but the distribution and severity of structural lesions between these two models may differ. Magnetic resonance imaging (MRI) studies have used quantitative measurements of hippocampal T2 (T2HP) relaxation time and volume, but simultaneous comparative results have not been reported yet. The aim of this study was to compare the MRI T2HP and volume with histological data and frequency of seizures in both models. KA- and PILO-treated rats were imaged with a 2 T MRI scanner. T2HP and volume values were correlated with the number of cells, mossy fiber sprouting, and spontaneous recurrent seizures (SRS) frequency over the 9 months following status epilepticus (SE). Compared to controls, KA-treated rats had unaltered T2HP, pronounced reduction in hippocampal volume and concomitant cell reduction in granule cell layer, CA1 and CA3 at 3 months post SE. In contrast, hippocampal volume was unchanged in PILO-treated animals despite detectable increased T2HP and cell loss in granule cell layer, CA1 and CA3. In the following 6 months, MRI hippocampal volume remained stable with increase of T2HP signal in the KA-treated group. The number of CA1 and CA3 cells was smaller than age-matched CTL group. In contrast, PILO group had MRI volumetric reduction accompanied by reduction in the number of CA1 and CA3 cells. In this group, T2HP signal was unaltered at 6 or 9 months after status. Reductions in the number of cells were not progressive in both models. Notably, the SRS frequency was higher in PILO than in the KA model. The volumetry data correlated well with tissue damage in the epileptic brain, suggesting that MRI may be useful for tracking longitudinal hippocampal changes, allowing the assessment of individual variability and disease progression. Our results indicate that the temporal changes in hippocampal morphology are distinct for both models of TLE and that these are not significantly correlated to the frequency of SRS.

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“…The other animals were not included in the data analysis because they either died before the testing period (during status or in the following days) or lost the caps. SE‐related mortality in the pilocarpine model typically ranges from 20 to 50% as previously described .…”

Section: Methodsmentioning

confidence: 99%