Significance of the plasma membrane for the nerve cell function, development and plasticity.

Lipoid character of plasma membrane namely the presence of polyenic fatty acids enables to interact with membrane proteins and in certain extent also to modulate their function. During the development, molecules of membrane fatty acids become more and more complex, and the ratio of polyenic fatty acids/saturated fatty acids in the brain rises, while the concentration of monoenic fatty acids remained relatively stable. This phenomenon is apparent also in the ratio of unsaturated fatty acids OMEGA-3 in plasma of newborns which correlates with the birth weight.

[Kainic acid and neurobiology].

Kainic acid, the analog of excitatory amino acid L-glutamate, interacts with specific receptors in the central nervous system. During last 25 years it has become a tool for studying many human brain disorders, for example human temporal lobe epilepsy, Huntington's chorea etc. Systemic administration of kainic acid results in neuronal death in experimental animals.

Neonatal administration of N-acetyl-L-aspartyl-L-glutamate induces early neurodegeneration in hippocampus and alters behaviour in young adult rats.

N-acetyl-L-aspartyl-L-glutamate (NAAG) is a dipeptide that could be considered a sequestered form of L-glutamate. As much as 25% of L-glutamate in brain may be present in the form of NAAG. NAAG is also one of the most abundant neuroactive small molecules in the CNS: it is an agonist at Group II metabotropic glutamate receptors (mGluR II) and, at higher concentrations, at the N-methyl-D-aspartate (NMDA) type of ionotropic glutamate receptors.

Neuronal cell death in hippocampus induced by homocysteic acid in immature rats.

Purpose: To examine the morphologic alterations in the cerebral cortex and hippocampus of immature rats 6 days after the generalized clonic-tonic seizures induced by homocysteic acid (HCA).

Methods: Seizures were induced by bilateral intracerebroventricular infusion of HCA (600 nmol per each side) in 12-day-old rats. After 6 days, rat pups were transcardially perfused under deep ether anesthesia with heparinized normal saline and subsequently with the fixation solution (4% paraformaldehyde in phosphate buffer, pH 7.

Nonconvulsive Seizures Result in Behavioral but Not Electrophysiological Changes in Developing Rats.

It is not known if nonconvulsive seizures lead to functional or morphological changes in immature rats. Therefore we studied consequences of such seizures induced by kainic acid (KA) on Postnatal Day (PD) 12 (2 mg/kg ip). The animals were examined electrophysiologically (cortical epileptic afterdischarges (ADs) were elicited in rats with implanted electrodes on PD 14, 18 or 25) and behaviorally (open field was studied in another group of animals on PDs 18 and 25).