Investigation of effects of two environmental heavy metals in a combined exposure model on the nervous system in rats

In the present study, the interaction of inhalational and oral exposure to manganese and lead was investigated. Young adult male Wistar rats (2 x 10 per group) were treated orally with MnCl2 (15 and 60 mg/kg b.w.) or Pb acetate (80 and 320 mg/kg) for 3 or 6 weeks. Then, one half of the groups was further treated by intratracheal instillation of nanoparticulate MnO2 (2.63 mg/kg) or PbO (2 mg/kg) for an equal period of time. Body weight gain and signs of general toxicity were regularly checked. Finally, the rats’ motor behavior was tested in an open field box, and their spontaneous and evoked cortical electrical activity was recorded in urethane anesthesia. MnO2 nanoparticles caused disproportionately strong reduction of body weight gain but with Pb the weight effect was more dependent on dose. In the open field test, Mn caused hypomotility, more strongly after 6 weeks oral plus 6 weeks intratracheal than after 6 weeks oral treatment. Pb-treated rats showed increased ambulation but less rearing and somewhat longer local activity. Spontaneous cortical activity was shifted to higher frequencies after oral Mn application, but this change was not intensified by subsequent nanoparticle application. Oral Pb had an opposite effect. Cortical evoked potentials showed latency lengthening. In several cases, the effect of Mn and Pb was about as strong after 3 weeks oral plus 3 weeks intratracheal as after 6 weeks oral administration, although the summed dose was ca. two times lower in the former case. There can be a more-than-additive interaction between the amounts of heavy metals entering the organism in different routes and chemical forms

The effects of 3-nitropropionic acid on the behavior and cortical electrical activity of rats in acute administration

In this study, the acute effects of 3-nitropropionic acid was investigated on open field and startle behavior of rats, and on their cortical electrical activity. Spontaneous locomotor activity, acoustic startle response, and pre-pulse inhibition of acoustic startle were measured in male Wistar rats (10 weeks old, 180-200g body weight) after a single dose of 10 or 20 mg/kg i.p. 3-nitropropionic acid. After the behavioral tests, the rats were anaesthetized, and spontaneous cortical electrical activity was recorded. The vertical, horizontal and local open field performance showed dose-dependent deterioration in the rats treated with 3-nitropropionic acid. The number of “noise-positive” startle responses showed non-significant changes, but the inhibition by pre-pulse was significantly reduced in the high dose animals. High dose also increased the proportion of low-frequencies in the cortical activity. Three-nitropropionic acid, known primarily to act in repeated doses (e.g., in animal models of Huntington’s disease) had also some clear-cut acute effects on behavioral and electrophysiological parameters of the treated rats

Phase-dependent molecular requirements for memory reconsolidation: differential roles for protein synthesis and protein kinase A activity

After consolidation, a process that requires gene expression and protein synthesis, memories are stable and highly resistant to disruption by amnestic influences. Recently, consolidated memory has been shown to become labile again after retrieval and to require a phase of reconsolidation to be preserved. New findings, showing that the dependence of reconsolidation on protein synthesis decreases with the age of memory, point to changing molecular requirements for reconsolidation during memory maturation. We examined this possibility by comparing the roles of protein synthesis (a general molecular requirement for memory consolidation) and the activation of protein kinase A (PKA) (a specific molecular requirement for memory consolidation), in memory reconsolidation at two time points after training. Using associative learning in Lymnaea, we show that reconsolidation after the retrieval of consolidated memory at both 6 and 24 h requires protein synthesis. In contrast, only reconsolidation at 6 h after training, but not at 24 h, requires PKA activity, which is in agreement with the measured retrieval-induced PKA activation at 6 h. This phase-dependent differential molecular requirement for reconsolidation supports the notion that even seemingly consolidated memories undergo further selective molecular maturation processes, which may only be detected by analyzing the role of specific pathways in memory reconsolidation after retrieval

Djelovanje 3-nitropropionske kiseline na štakore: opća toksičnost i funkcijska neurotoksičnost

3-Nitropropionic acid (3-NP) causes biochemical and morphological alterations in human and animal brain. Young adult male Wistar rats received 3-NP i. p. on five consecutive days and were investigated four weeks later (subacute treatment). Acute effects were investigated 24 h after one i. p. dose. Spontaneous or stimulus-evoked activity was recorded from cortical sensory foci, from subcortical nuclei and from the tail nerve, in urethane anesthesia. The subacutely treated rats were dissected and organ weights measured to study general toxic effects. After subacute treatment, decrease was seen in the theta, and increase in the beta-2 and gamma, band of the spontaneous activity, dissimilarly in the cortical vs. subcortical sites. Latency of the sensory evoked potentials increased in all sensory foci after subacute treatment. Following acute treatment, amplitude of the somatosensory evoked potential decreased. The weight of the thymus decreased significantly in the treated rats. Further studies could elucidate the link between biochemical effects of 3-NP and the observed functional neurotoxic changes.Toksin 3-nitropropionska kiselina (3-NP) uzrokuje biokemijske i morfološke promjene u mozgu. U istraživanju su mladi muški Wistar štakori intraperitonealno primali 3-NP pet dana uzastopce. Djelovanje toksina promatrano je četiri tjedna kasnije (subakutna primjena). Akutni su učinci promatrani 24 sata nakon intraperitonealne primjene. Spontana i podražajno izazvana aktivnost mjerena je na osjetilnim žarištima korteksa, na supkortikalnim jezgrama te na repnome živcu, dok su životinje bile pod uretanskom anestezijom. Nakon subakutnoga doziranja zamijećen je rast beta-2 i gama-valova kod spontane aktivnosti. Ova promjena nije bila istovjetna na kori i pod korom mozga. Stimulirana osjetilna aktivnost u ove je subakutne skupine pokazala povećanu latenciju u svim osjetilnim područjima. U štakora koji su primili jednokratnu akutnu dozu amplituda evociranoga somatosenzornoga potencijala bila je manja. Masa prsne žlijezde bila je značajno niža u štakora koji su primili 3-NP. Potrebna su daljnja istraživanja koja bi razjasnila povezanost između biokemijskoga djelovanja 3-NP-a i zamijećenih neurotoksičnih funkcijskih promjena

Effects of 3-nitrpropionic acid in rats: general toxicity and neurotoxicity

Three-nitropropionic acid (3-NP) causes biochemical and morphological alterations in human and animal brain. Young adult male Wistar rats received 3-NP ip. on 5 consecutive days and were investigated four weeks later (subacute treatment). Acute effects were investigated 24 h after one ip. dose. Spontaneous or stimulus-evoked activity was recorded from cortical sensory foci, from subcortical nuclei and from the tail nerve, in urethane anesthesia. The subacutely treated rats were dissected and organ weights measured to study general toxic effects. After subacute treatment, decrease was seen in the theta, and increase in the beta2 and gamma, band of the spontaneous activity, dissimilarly in the cortical vs. subcortical sites. Latency of the sensory evoked potentials increased in all sensory foci after subacute treatment. Following acute treatment, amplitude of the somatosensory evoked potential decreased. The weight of the thymus decreased significantly in the treated rats. Further studies could elucidate the link between biochemical effects of 3-NP and the observed functional neurotoxic changes

Stimulus frequency dependence of the central and peripheral somatosensory evoked activity in rats treated with various pesticides

Rats were treated with a combination of insecticide agents in different timing schemes. In acute administration, 1/5 LD50 of the three insecticides: dimethoate, propoxur and cypermethrin, or their combination, was given once by gavage. In the developmental model, female rats received oral doses of 1/25 LD50 of the above insecticides in combination in three timing schemes including pregnancy and lactation. Responses in the somatosensory cortex and in the tail nerve, evoked by peripheral electric stimulation, were recorded in acute preparation under urethane anesthesia. It was tested whether the parameters of the cortical and peripheral evoked response are dependent on the frequency and whether this dependence is different in control and treated animals. The latency increase of the cortical responses with increasing stimulation frequency was significantly stronger in rats treated acutely with cypermethrin and the combination, and in rats receiving the combination during both intra- and extrauterine development. On the duration, the effects were less clear. Frequency dependent increase of the tail nerve action potential latency was significantly intensified by cypermethrin, and the amplitude decrease, by cypermethrin and dimethoate. Fatigue of this response during a stimulation series was also altered by the insecticides. Frequency dependence and fatigue possibly reflect the actual state of the nervous system and may have the potency to be developed to functional biomarkers. Š 2005 AkadÊmiai Kiadó

Terminográfiai módszerek és eszközök a terminológusképzésben.

Az cikk célja a Károli Gáspár Református Egyetemen folyó MA szintű terminológusképzés bemutatása, konkrétan pedig annak tárgyalása, hogy a képzésben milyen hangsúlyt fektetünk a modern terminográfiai módszerek és eszközök hallgatókkal történő megismertetésére. A Terminológia mesterszak létesítése és indítása több évvel ezelőtt kezdődött meg azért, hogy bevezethessük Magyarországon is az egyetemi szintű terminológusképzést. A Terminológia mesterszak két éves egyetemi képzés, a bölcsészkaron folyik. A képzés bemenete kettős: egyrészt bölcsész BA végzettségűek jelentkezhetnek rá (magyar és idegen nyelv szakosok), másrészt más, szakmai BA (vagy MA) végzettséggel rendelkezők (például mérnökök, közgazdászok, jogászok, orvosok) jelentkezését is várjuk. A terminológia nemcsak mint önmagáért létező (bölcsészet)tudomány működik. Valódi gyakorlati haszna kimutatható akár egy vállalkozás sikerességében is. A rendszerben gondolkodó terminológus mozgatórugója lehet nemcsak a fordítóirodáknak, hanem − éppen a rendszerszemléletnek köszönhetően − bármely multilingvális, multinacionális cégnek. A terminológusok oktatása során a tananyag tervezésében az egyik fontos kérdés annak meghatározása, hogy a lexikográfia és a terminológia legfontosabb elveinek, módszereinek tárgyalásán túl milyen modern eszközök használatára, tartalmi és formai jellemzőinek bemutatására fektessünk hangsúlyt a képzésben