Surface charge impact in low-magnesium model of seizure in rat hippocampus.

Putative mechanisms of induction and maintenance of seizure-like activity (SLA) in the low Mg(2+) model of seizures are: facilitation of NMDA receptors and decreased surface charge screening near voltage-gated channels. We have estimated the role of such screening in the early stages of SLA development at both physiological and room temperatures. External Ca(2+) and Mg(2+) promote a depolarization shift of the sodium channel voltage sensitivity; when examined in hippocampal pyramidal neurons, the effect of Ca(2+) was 1.

Effect of neuraminidase treatment on persistent epileptiform activity in the rat hippocampus.

Negatively charged sialic acid residues located close to pores of voltage-gated sodium channels substantially influence their gating properties. The in vitro low Mg²⁺ seizure model is used to emulate difficult-to-treat status epilepticus. Using this model on cultured hippocampal slices, we examined the effectiveness of desialylation in reducing persistent seizure-like activity.

Blockade of endogenous neuraminidase leads to an increase of neuronal excitability and activity-dependent synaptogenesis in the rat hippocampus.

Polysialic acids are widely distributed in neuronal tissue. Due to their position on glycoproteins and gangliosides on the outer cell membranes and anionic nature, polysialic acids are involved in multiple cell signaling events. The level of sialylation of the cellular surface is regulated by endogenous neuraminidase (NEU), which catalyses the hydrolysis of terminal sialic acid residues.

Recurrent neonatal seizures result in long-term increases in neuronal network excitability in the rat neocortex.

Neonatal seizures are associated with a high likelihood of adverse neurological outcomes, including mental retardation, behavioral disorders, and epilepsy. Early seizures typically involve the neocortex, and post-neonatal epilepsy is often of neocortical origin. However, our understanding of the consequences of neonatal seizures for neocortical function is limited.