A novel hydro-pneumatic fluid percussion device for inducing traumatic brain injury: assessment of sensory, motor, cognitive, molecular, and morphological outcomes in rodents.

Introduction: The fluid percussion method is widely used to induce brain injury in rodents. However, this approach has several limitations, including variability in the resulting damage, which is attributed to factors such as manual control of the mass used to generate the desired pressure. To address these issues, several modifications to the original method have been proposed. Methods: In this study, we present a novel device called the Hydro-pneumatic Fluid Percussion Device, which delivers fluid directly to a lateral region of the brain to induce injury. To validate this model, three groups of male and female rats were subjected to lateral fluid percussion using our device, and the resulting damage was evaluated using sensory, motor, and cognitive tests, measurements of serum injury biomarkers, and morphological analysis via cresyl violet staining. Results: Our results demonstrate that this new approach induced significant alterations in all parameters evaluated. Discussion: This novel device for inducing TBI may be a valuable alternative for modeling brain injury and studying its consequences.

Connexins-Based Hemichannels/Channels and Their Relationship with Inflammation, Seizures and Epilepsy.

Connexins (Cxs) are a family of 21 protein isoforms, eleven of which are expressed in the central nervous system, and they are found in neurons and glia. Cxs form hemichannels (connexons) and channels (gap junctions/electric synapses) that permit functional and metabolic coupling between neurons and astrocytes. Altered Cx expression and function is involved in inflammation and neurological diseases. Cxs-based hemichannels and channels have a relevance to seizures and epilepsy in two ways: First, this pathological condition increases the opening probability of hemichannels in glial cells to enable gliotransmitter release, sustaining the inflammatory process and exacerbating seizure generation and epileptogenesis, and second, the opening of channels favors excitability and synchronization through coupled neurons. These biological events highlight the global pathological mechanism of epilepsy, and the therapeutic potential of Cxs-based hemichannels and channels. Therefore, this review describes the role of Cxs in neuroinflammation and epilepsy and examines how the blocking of channels and hemichannels may be therapeutic targets of anti-convulsive and anti-epileptic treatments.

Effect of Chronic Krill Oil Supplement on Seizures Induced by Pentylenetetrazole in the Hippocampus of Adult Rats with Previous Febrile Seizures.

We evaluated the effect of krill oil (KO) supplement on seizures induced by pentylenetetrazole (PTZ) in animals with previous febrile seizures (FSs) induced by hyperthermia to determine its effectiveness in seizure susceptibility and as an anticonvulsant. Male Wistar rats with FS separated into water (W, 1 mL), palm oil (PO, 300 mg/kg, total volume 1 mL), or KO (300 mg/kg, total volume 1 mL) groups. All drugs were administered chronically via the intragastric route. Electrical activity was recorded by intracranial EEG simultaneously with convulsive behavior. All animals' brains were processed by immunofluorescence against GFAP, NeuN, and connexins (Cx); cellular quantification was performed in hippocampus and pyramidal or granular layer thickness was evaluated with cresyl violet (CV) staining. The results showed a significant delay in convulsive behavior and a slight increased survival time after PTZ administration in the group treated with KO compared with PO and W groups. The epileptiform activity showed high amplitude and frequency, with no significant differences between groups, nor were there differences in the number and duration of discharge trains. KO and PO increased the number of astrocytes and the number of neurons compared with the W group. KO and PO decreased the expression of Cx36 without affecting Cx43 expression or the thickness of layers. Based on these data, we consider it important to perform more experiments to determine the anticonvulsant role of KO, taking into account the partial effect found in this study. KO could be used as a coadjuvant of traditional anticonvulsive treatments. PRACTICAL APPLICATION: In this study was evaluated the anticonvulsive effect of a chronic krill oil (KO) supplement in animals with seizures. Results showed that KO had partial anticonvulsive effects measured by EEG activity and convulsive behavior analysis. These data justify further research that looks at KO supplementation as a prospective coadjuvant of pharmacologic management of seizure disorder.

A novel online fluorescence method for in-vivo measurement of hydrogen peroxide during oxidative stress produced in a temporal lobe epilepsy model.

Status epilepticus (SE) can result in an overproduction of hydrogen peroxide (H2O2), which contributes to oxidative stress and brain injury during different phases of epileptogenesis and seizures. In this study, we measured the extracellular H2O2 concentration in the rat hippocampus in a temporal lobe epilepsy model. A new fluorescent technique for measuring H2O2 in vivo simultaneously with electroencephalography recording was tested. The method consists of mixing microdialysate with an enzymatic reactor to produce a fluorescent compound. The fluorescence intensity was measured every second and was proportional to the H2O2 concentration. The results showed that H2O2 was released during SE; we detected a significant increase of up to five times over the baseline value that correlated with changes in electrical activity. We also observed that H2O2 was produced for days after SE and was associated with continuous neuronal death and seizure generation. Therefore, we monitored H2O2 48 h and 15 days after SE, observing increases of up to 96 and 124%, respectively, accompanied by changes in electrical activity with spontaneous discharges of large amplitude. These changes may reflect the oxidative stress generated during epileptogenesis that remains during the chronic period (458% increased) with the presence of large spikes, indicating that the H2O2 could also participate in the generation and maintenance of spontaneous recurrent seizures. There are no previous reports on the detection of H2O2 at this temporal resolution; thus, this study contributes a novel technique for studying and understanding epileptogenesis to develop new antioxidant strategies for the treatment of temporal lobe epilepsy.