Influence of low-dose neonatal domoic acid on the spontaneous behavior of rats in early adulthood.

Consumption of seafood containing toxin domoic acid (DA) causes an alteration of glutamatergic signaling pathways and could lead to various signs of neurotoxicity in animals and humans. Neonatal treatment with domoic acid was suggested as valuable model of schizophrenia and epilepsy. We tested how repeated early postnatal DA administration influences the spontaneous behavior of rats in adulthood.

Magnesium and posthypoxic changes of nitrergic population in rat hippocampus.

We used NADPH-diaphorase staining to study effects of magnesium pre-treatment during long-lasting hypoxia on the brain structure of rats. NADPH-diaphorase is an enzyme co-localized in neurons with NO-synthase that is responsible for NO synthesis. NO participates in hypoxic-ischaemic injury of the brain.

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.

Pentylentetrazol associated changes of hippocampal neurons in immature rats.

Using histochemical analysis, the NADPH-diaphorase, Fluoro-Jade B and bis-benzimide (Hoechst 33342) the effect of intraperitoneal administration of pentylentetrazol (PTZ) on hippocampal neurons was studied. 18-day-old male rats of the Wistar strain received PTZ (60 mg/kg) in one dose. The next day, the 19-day-old animals were transcardially perfused with 4% paraformaldehyde under deep thiopental anaesthesia.

Neuroprotective effect of (R, S)-4-phosphonophenylglycine against neuronal damage associated with homocysteic acid-induced seizures in immature rats.

Incidence of human epilepsy in infants and children is high and prolonged seizures in the early developmental period can cause brain damage and lead to serious consequences later in the life. The present study was aimed to investigate potential protective effect of (R, S)-4-phosphonophenylglycine ((R, S)-PPG), a potent and selective group III mGluR agonist, on brain damage associated with homocysteic acid-induced seizures in immature 12-day-old rats. This compound does not exhibit any proconvulsive effect.

Kainic acid and nitrergic neurons in immature hippocampus.

Using histochemical analysis the effect of intraperitoneal administration of kainic acid on hippocampal neurons was studied. 18-day-old male rats of the Wistar strain received kainic acid (10mg/kg) in one dose. Two days later, the 20-day-old animals were transcardially perfused with 4% paraformaldehyde under deep thiopental anaesthesia.

Changes of hippocampal neurons after perinatal exposure to ethanol.

The effect of ethanol on the structural development of the central nervous system was studied in offspring of Wistar rats, drinking 20 % ethanol during pregnancy and till the 28th day of their postnatal life. The structural changes in the hippocampus and dentate gyrus were analyzed at the age of 18, 35 and 90 days. A lower width of pyramidal and granular cell layers, cell extinction and fragmentation of numerous nuclei were found in all experimental animals compared to control animals.

Morphological changes in the hippocampus following nicotine and kainic acid administration.

Using histochemical analysis (NADPH-diaphorase, Fluoro-Jade B dye and bis-benzimide 33,342 Hoechst) we studied the influence of intraperitoneal administration of nicotine (NIC), kainic acid (KA) and combination of both these substances on hippocampal neurons and their changes. In experiments, 35-day-old male rats of the Wistar strain were used. Animals were pretreated with 1 mg/kg of nicotine 30 min prior to the kainic acid application (10 mg/kg).

Magnetic resonance imaging of the rat brain after epileptic seizures--preliminary results.

The magnetic resonance imaging (MRI) of the rat brain after the epilepsy seizures has been performed. As a first step, the model of the kainic acid (KA) induced seizures has been conducted to examine the possibilities of magnetic resonance imaging system kept in disposition. Seven Wistar albino rats, weighing about 300 g, were used in this study.

Changes in the number of nitrergic neurons in rats hippocampus following nicotine administration.

Nicotine is a very widely used drug of abuse, which exerts a number of neurovegetative behavioural effects by interacting with the neuronal nicotinic acetylcholine receptor. Using histochemical analysis (NADPH-diaphorase and Fluoro-Jade B dye), the influence of intraperitoneal administration of nicotine on neurons of the hippocampus in 35-day-old male rats of the Wistar strain was studied. At the age of 37 days, the animals were transcardially perfused with 4% paraformaldehyde under deep thiopental anaesthesia.

Effect of magnesium pre-treatment on the hippocampal NOS activity during long-lasting intermittent hypoxia.

Influence of magnesium pre-treatment during repetitive hypoxia was studied in the hippocampus of rats by histochemical analysis (NADPH-diaphorase staining). NADPH-diaphorase occurs concurrently with NO-synthase that is responsible for NO synthesis. Rat pups were kept together with their mother for 8 hours a day in a hypobaric chamber at a simulated altitude of 7,000 m since the day of birth till the 17th day.

Alcohol abuse in mothers during gravidity and breastfeeding brings changes of hippocampal neurons in their offspring.

Neurotoxic effect of ethanol on the CNS of laboratory rats in the prenatal and postnatal period was studied. Another aim of the experiment was to analyse structure of the hippocampus after the prenatal and postnatal exposure to alcohol and to identify the most vulnerable hippocampal regions. Pregnant Wistar rats of our own breed received 20% alcohol p.

Nicotine an efficient tool of the neurobiological research today, the tool of treatment tomorrow?

Nicotine is a very widely used drug of abuse, which has many neurovegetative behavioural and psychological effects by interacting with neuronal nicotinic acetylcholine receptor. Cholinergic receptors can be divided into two types, muscarinic and nicotinic, based on the pharmacological action of various agonists and antagonists. This review summarises the major recent findings of nicotine effects in order to show the use of this drug in the neurophysiological research and namely as a potential tool for the treatment of some brain disorders.

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.

Intermittent hypobaric hypoxia during development--morphological and functional changes in the neocortex.

Infant rats, together with their mother, were exposed to the simulated altitude of 7,000 m for 8 hours per day since birth to the age of 17 days. Animals were studied the 25th day, 8 days after the last exposure to hypoxia. The experimental and control animals were sacrificed the 25th day by the transaortic perfusion with 4% buffered neutral formaldehyde under ether anaesthesia.

[Neuronal network].

Function of the central nervous system is based on mutual relations among the nerve cells. Description of nerve cells and their processes, including their contacts was enabled by improvement of optical features of the microscope and by the development of impregnation techniques. It is associated with the name of Antoni van Leeuwenhoek (1632-1723), J.

Repeated kainic acid administration and hippocampal neuronal degeneration.

Many animal models have been established to study the mechanisms leading to excitotoxicity. One of the more commonly used models is kainic acid (KA) induced excitotoxicity. Upon administration of KA in rodents, KA produces acute status epilepticus and neuronal damage.

Effect of the perinatal alcohol abuse on the development of neuronal population in the hippocampus.

The study deals with neurotoxic effects of alcohol on the CNS of laboratory rats in the prenatal period. The aim of the experiment is to analyse structure of the hippocampus after the prenatal exposure to alcohol and to identify the most vulnerable hippocampal regions. Pregnant Wistar rats of our own breed received alcohol (2 g per 100 g of body i.

Plasticity of the brain in neuroontogenesis.

Plasticity is a specific endowment of the nervous system to develop, to react or to adjust to the internal and external 'environmental changes, both in the physiological and pathological conditions. Cumulative evidence has revealed the dynamism of the nervous system, based on the balance between the rigidity and plasticity. Different aspects of neuroplasticity can employ common general cellular mechanism.

Long-lasting changes in the density of nitrergic neurons following kainic acid administration and chronic hypoxia.

Using histochemical analysis (NADPH-diaphorase) we have investigated the influence of intraperitoneal administration of kainic acid (KA), hypoxia and combination of both these factors on neurons of the hippocampus and on the primary auditory cortex (PAC) in male rats of the Wistar strain. Kainic acid was administered to 18-day-old animals, which were exposed to long-lasting repeated hypoxia from the 2nd till the 17th day of age in a hypobaric chamber (for 8 hours a day). At the age of 1 year, the animals were transcardially perfused with 4 % paraformaldehyde under deep thiopental anesthesia.

Changes in the number of nitrergic neurons following kainic acid administration and repeated long-term hypoxia.

Using histochemical analysis (NADPH-diaphorase) we have been investigating the influence of intraperitoneal administration of kainic acid (KA), hypoxia and combination of both these factors on neurons of the hippocampus and on the primary auditory cortex (PAC) in male rats of the Wistar strain. Kainic acid was administered to 18-day-old animals, which were exposed to long-lasting repeated hypoxia from the 2nd till the 17th day of age in a hypobaric chamber (for 8 h a day). At the age of 22 or 90 days, the animals were transcardially perfused with 4 % paraformaldehyde under deep thiopental anesthesia.

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).