Imbalance of the excitatory neurotransmitter glutamate and of the inhibitory neurotransmitter GABA is one of several causes of seizures. ATP has also been implicated in epilepsy. However, little is known about the mechanisms involved in the release of ATP from cells and the consequences of the altered ATP signaling during seizures. Pannexin1 (Panx1) is found in astrocytes and in neurons at high levels in the embryonic and young postnatal brain, declining in adulthood. Panx1 forms large-conductance voltage sensitive plasma membrane channels permeable to ATP that are also activated by elevated extracellular K+ and following P2 receptor stimulation. Based on these properties, we hypothesized that Panx1 channels may contribute to seizures by increasing the levels of extracellular ATP. Using pharmacological tools and two transgenic mice deficient for Panx1 we show here that interference with Panx1 ameliorates the outcome and shortens the duration of kainic acid-induced status epilepticus. These data thus indicate that the activation of Panx1 in juvenile mouse hippocampi contributes to neuronal hyperactivity in seizures.

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Despite certain limitations, our new model correlates well with current infantile spasm hypotheses and opens an opportunity for development and testing of new effective drugs.

An 8-month multicentre prospective randomized study aimed at comparing the effects of dopamine receptor agonists pramipexole (PPX; Mirapexin) and pergolide (PRG; Permax) as add-on to L-dopa therapy on depression [Montgomery and Asberg Depression Rating Scale (MADRS)] in 41 non-demented patients (25 men, 16 women) suffering from both mild or moderate depression and advanced Parkinson's disease (PD). The assessment was performed by a blinded independent observer. Motor symptoms (UPDRS III), motor complications (UPDRS IV), activities of daily living (UPDRS II and VI) and depressive symptoms as measured by Self - Rating Depression Scale by Zung were evaluated in an open-label design. The average value of Zung scores decreased significantly in both groups with no statistical difference between both groups. A significant decrease in the average value of MADRS scores was present only in the PPX group. The average UPDRS scores decreased significantly with no statistical difference between both groups at the comparable average total daily dose of both preparations. In both cases, the total daily dose of L-dopa decreased significantly but the decrease was statistically more pronounced in the PRG group. Our results demonstrate the antidepressant effect of PPX in patients with PD while we can't make any conclusions with regard to antidepressant effect of PRG.

Summary: Purpose:We investigated the activation of microglia and astrocytes, induction of cytokines, and hippocampal neuronal damage, 4 and 24 h after kainic acid-induced status epilepticus (SE) in postnatal day (PN) 9, 15, and 21 rats.Methods: Limbic seizures were induced by systemic injection of kainic acid. Glia activation and neuronal cell loss were studied by using immunocytochemistry and Western blot. Cytokine expression was analyzed by reverse transcriptasepolymerase chain reaction (RT-PCR) followed by Southern blot quantification.Results: After SE onset, hippocampal glia activation, cytokine expression, and neuronal damage are all age-dependent phenomena. In the hippocampus, neuronal injury occurs only when cytokines are induced in glia, and cytokine synthesis precedes the appearance of degenerating neurons. Neuronal injury is more pronounced when interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) are produced in addition to .Conclusions: This study shows that cytokine induction in rat brain after sustained seizures is age dependent, and it is associated with the appearance of cell injury. Key Words: Brain development-Interleukins-Neurodegeneration-Hippocampus-Seizures-Rat.Proinflammatory cytokines and related inflammatory and antiinflammatory molecules are rapidly overexpressed by glia in adult rodent hippocampus in various models of limbic seizures (1-3). In the adult brain, cytokines are expressed to a larger extent when seizures are associated with neuronal damage, suggesting a link between cytokine production and the occurrence of neuronal injury (1,4). Thus it has been shown that in mature rat brain, proinflammatory cytokines, and in particular interleukin (IL)-1β, act as modulators of various forms of neurodegeneration (5-7).In humans and in experimental models of epilepsy, seizure susceptibility and the associated neuronal damage are age-dependent phenomena, changing dramatically during postnatal development. In the first 2 postnatal weeks, the brain is more prone to seizure activity, but it is relatively resistant to irreversibile seizure-induced damage as compared with adult brain (8-12).The factors implicated in the occurrence of agedependent seizure-related injury are still unclear. We

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The substantia nigra is an important brain nucleus involved in the expression of movement disorders and seizures. The two most common movement disorders affecting the substantia nigra, Parkinson's disease and Tourette syndrome, show gender differences and age-related onset. To assess the substrates for the gender and age specificity of substantia nigra-related disorders, we determined the functional properties of the substantia nigra gamma-aminobutyric acid (GABAA) system along its anterior-posterior axis, using localized microinfusions of muscimol (a GABAA agonist) and susceptibility to motor seizures in rats. In the substantia nigra, there are sex-specific differences in the topographic segregation and functionality of GABAA systems. In mature male rats there are two distinct regions mediating opposite effects on seizures; in female rats there is only one region that can affect seizures. In the neonatal period, the presence of circulating testosterone is essential for the development of a substantia nigra region that exerts proconvulsant effects throughout the rat's life, a unique feature of the male substantia nigra. The final maturation of the substantia nigra occurs in the peripubertal period, and is in part regulated by testosterone as well. The recognition of the existence of distinct sex- and age-specific substantia nigra features can be translated into new cures of disorders affecting the substantia nigra.

Summary:Purpose: Estrogens have neuroprotective effects in ischemia, stroke, and other conditions leading to neuronal cell death (e.g., Alzheimer's disease). The present study examined whether estrogens may have neuroprotective effects after seizures.Methods: The kainic acid model was used to determine if estrogens protect hippocampal cells after status epilepticus in adult female rats. Rats were ovariectomized 1 week before hormone replacement. P-Estradiol benzoate (EB; 2 k g in 0.1 mL of oil) was injected subcutaneously 48 and 24 hours before seizure testing. We administered kainic acid (16 mg/kg intraperitoneally) and behaviorally monitored the rats for 5 hours. After this time, all rats were injected with pentobarbital (50 mg/kg intraperitoneally) irrespective of seizure severity. Some rats received two additional doses of EB, one immediately and one 24 hours after the seizures. Another group of rats received only these two doses of EB after the seizures, and yet another group of rats received pretreatment with the intracellular EB receptor antagonist tamoxifen before each of four EB injections. Control rats received oil instead of EB. Rats were killed 48 hours after seizures. Neuronal damage was evaluated in silver-impregnated and Nissl-stained sections.Results: Estrogen treatment before kainic acid administration significantly delayed the onset of kainic acid-induced clonic seizures, whereas it did not change the onset of status epilepticus compared with oil-treated controls. Furthermore, estrogen treatment significantly protected against kainic acid-induced seizure-related mortality. In control rats, examination of Nisslstained and silver-impregnated slides revealed severe neuronal damage in the vulnerable pyramidal neurons of the hippocampal CA3 subfield and in the hilus of the dentate gyrus. Estrogen pretreatment, as well as the combination of pretreatment and posttreatment, significantly reduced the number of argyrophilic neurons in both the CA3 and the dentate gyrus. Posttreatment only had no protective effects. The data indicate that intracellular EB receptors mediate this type of neuroprotective effect, because the tamoxifen pretreatment abolished EB neuroprotection.Conclusions: Our results suggest that estrogens can be beneficial in protecting against status epilepticus-induced hippocampal damage. Hormonal conditions may have differential effects on underlying epileptic state in some patients. Therefore, more studies are necessary to determine the prospective therapeutic advantage of hormonal treatment in seizure-related damage.Estrogens are sex hormones that have major effects on the female reproductive system. There is increasing evidence, however, that estrogens also influence brain development and ongoing modulation of nervous system function (1). In women, the loss of estrogens at menopause may account for the increased incidence of neurodegenerative diseases (2-4). Treatment with estrogens during the postmenopausal period can delay the onset and decrease the risk of pathological conditions re...