RESUMO
The hydrolysis of effluent from a poultry slaughterhouse containing 800 mg oil and grease (O&G)/L was conducted with 1% (w/v) of an enzymatic pool obtained by solid-state fermentation with the fungus Penicillium restrictum. The chromatographic evaluation of the lipid profile during hydrolysis indicated a higher concentration of acids after 4h of reaction (2954 mg/L), with a predominance of oleic, palmitic, and linoleic acids. Effluent aliquots were collected after 4, 8, and 24h of hydrolysis and tested for anaerobic biodegradation in sequential batches. An adaptation of the biomass was observed, both in the control experiment (with non-hydrolyzed raw effluent) and in the experiments with enzymatically pre-treated effluent. The specific methane production in the control experiment was 0.248 L CH(4)/g COD(consumed), and in the experiment with effluent pre-treated for 4h, this production was 0.393 L CH(4)/g COD(consumed), indicating a higher methane production after enzymatic hydrolysis.
Assuntos
Matadouros , Ácidos Graxos/análise , Aves Domésticas , Triglicerídeos/análise , Eliminação de Resíduos Líquidos , Anaerobiose , Animais , Biodegradação Ambiental , Biocombustíveis/análise , Hidrólise , Lipase/metabolismo , Metano/análise , Esgotos/química , Fatores de TempoRESUMO
The treatment of neurological disorders and neurodegenerative diseases is related to the levels of acetylcholine (ACh) through the inhibition of acetylcholinesterase (AChE). Galanthamine, an important alkaloid isolated from the Amaryllidaceae family, is approved for the pharmacological treatment of Alzheimer's disease (AD) and acts by inhibiting the acetylcholinesterase (AChE) activity. In the present study, Ellman's method was used to verify the inhibition of AChE activity of some isoquinolines alkaloids such as galanthamine, montanine, hippeastrine and pretazettine. At the concentrations 1mM, 500 microm and 100 microm, galanthamine presented an AChE inhibition higher than 90%. Montanine inhibited, in a dose-dependent manner, more than 50% of the enzyme at 1mM concentration. With the concentrations 500 microm and 100 microm, 30-45% of AChE activity inhibition was detected. The alkaloids hippeastrine and pretazettine presented no significant inhibition of the AChE activity. The results demonstrate that montanine significantly inhibits AChE activity at the tested concentrations, suggesting the necessity of further investigations on this alkaloid use in treating neurological disorders.
Assuntos
Acetilcolinesterase/metabolismo , Alcaloides/farmacologia , Inibidores da Colinesterase/farmacologia , Isoquinolinas/farmacologia , Liliaceae/química , Extratos Vegetais/farmacologia , Relação Dose-Resposta a Droga , Extratos Vegetais/química , Raízes de PlantasRESUMO
The effect of different hydrolysis times (4, 8 and 24 h) of a lipase-rich enzymatic preparation (0.1, 0.5 and 1.0% w/v) produced by fungus Penicillium sp. in solid-state fermentation was evaluated on the anaerobic biodegradability of a poultry slaughterhouse wastewater with 800 mg oil and grease [O&G]/L in three sequential batches. The enzymatic pre-treatment of O&G in the experiments with no acclimated sludge had no discernible effect because regardless of the conditions adopted COD removal efficiencies of 95.3% to 98.7% were obtained. However, when the sludge was reused (once or twice) the COD removal efficiencies in the control experiments (69.8% and 53.4%) were considerably lower than in the experiments with hydrolyzed effluent (of 93.8% to 98.4%). Higher values of specific methane production were obtained with 0.1% SEP and 4 h of hydrolysis. After acclimation of the sludge, 19.9% fat was still adhered to the sludge in the control experiment, while the sludge in the experiment with enzymatically pre-treated effluent contained only 8.6% fat, confirming the accumulation of fat when the enzyme pool was not used.
Assuntos
Matadouros , Gorduras/química , Aves Domésticas , Eliminação de Resíduos Líquidos/métodos , Animais , Hidrólise , Metano/químicaRESUMO
Early-life environmental events, such as the handling procedure, can induce long-lasting alterations upon several behavioral and neuroendocrine systems. However, the changes within the pups that could be causally related to the effects in adulthood are still poorly understood. In the present study, we analyzed the effects of neonatal handling on behavioral (maternal odor preference) and biochemical (cyclic AMP response element-binding protein (CREB) phosphorylation, noradrenaline (NA), and serotonin (5-HT) levels in the olfactory bulb (OB)) parameters in 7-day-old male and female rat pups. Repeated handling (RH) abolished preference for the maternal odor in female pups compared with nonhandled (NH) and the single-handled (SH) ones, while in RH males the preference was not different than NH and SH groups. In both male and female pups, RH decreased NA activity in the OB, but 5-HT activity increased only in males. Since preference for the maternal odor involves the synergic action of NA and 5-HT in the OB, the maintenance of the behavior in RH males could be related to the increased 5-HT activity, in spite of reduction in the NA activity in the OB. RH did not alter CREB phosphorylation in the OB of both male and females compared with NH pups. The repeated handling procedure can affect the behavior of rat pups in response to the maternal odor and biochemical parameters related to the olfactory learning mechanism. Sex differences were already detected in 7-day-old pups. Although the responsiveness of the hypothalamic-pituitary-adrenal axis to stressors is reduced in the neonatal period, environmental interventions may impact behavioral and biochemical mechanisms relevant to the animal at that early age.
Assuntos
Monoaminas Biogênicas/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Manobra Psicológica , Comportamento Materno , Odorantes , Bulbo Olfatório/metabolismo , Análise de Variância , Animais , Animais Recém-Nascidos , Cromatografia Líquida de Alta Pressão/métodos , Condicionamento Psicológico , Eletroquímica/métodos , Feminino , Masculino , Gravidez , Ratos , Ratos Wistar , Fatores Sexuais , Transdução de Sinais/fisiologiaRESUMO
Storage of acetylcholine in synaptic vesicles plays a key role in maintaining cholinergic function. Here we used mice with a targeted mutation in the vesicular acetylcholine transporter (VAChT) gene that reduces transporter expression by 40% to investigate cognitive processing under conditions of VAChT deficiency. Motor skill learning in the rotarod revealed that VAChT mutant mice were slower to learn this task, but once they reached maximum performance they were indistinguishable from wild-type mice. Interestingly, motor skill performance maintenance after 10 days was unaffected in these mutant mice. We also tested whether reduced VAChT levels affected learning in an object recognition memory task. We found that VAChT mutant mice presented a deficit in memory encoding necessary for the temporal order version of the object recognition memory, but showed no alteration in spatial working memory, or spatial memory in general when tested in the Morris water maze test. The memory deficit in object recognition memory observed in VAChT mutant mice could be reversed by cholinesterase inhibitors, suggesting that learning deficits caused by reduced VAChT expression can be ameliorated by restoring ACh levels in the synapse. These data indicate an important role for cholinergic tone in motor learning and object recognition memory.
Assuntos
Deficiências da Aprendizagem/genética , Proteínas Vesiculares de Transporte de Acetilcolina/biossíntese , Proteínas Vesiculares de Transporte de Acetilcolina/genética , Animais , Relação Dose-Resposta a Droga , Imunofluorescência , Deficiências da Aprendizagem/psicologia , Aprendizagem em Labirinto/fisiologia , Rememoração Mental/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Atividade Motora/fisiologia , Destreza Motora/fisiologia , Terminações Nervosas/metabolismo , Equilíbrio Postural/fisiologia , Desempenho Psicomotor/fisiologia , Reconhecimento Psicológico/fisiologiaRESUMO
Memory consolidation involves a sequence of temporally defined and highly regulated changes in the activation state of several signaling pathways that leads to the lasting storage of an initially labile trace. Despite appearances, consolidation does not make memories permanent. It is now known that upon retrieval well-consolidated memories can become again vulnerable to the action of amnesic agents and in order to persist must undergo a protein synthesis-dependent process named reconsolidation. Experiments with genetically modified animals suggest that some PKC isoforms are important for spatial memory and earlier studies indicate that several PKC substrates are activated following spatial learning. Nevertheless, none of the reports published so far analyzed pharmacologically the role played by PKC during spatial memory processing. Using the conventional PKC and PKCmu inhibitor 12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo[2,3-a]pyrrollo[3,4-c]carbazole (Gö6976) we found that the activity of these kinases is required in the CA1 region of the rat dorsal hippocampus for acquisition and consolidation of spatial memory in the Morris water maze learning task. Our results also show that when infused into dorsal CA1 after non-reinforced retrieval, Gö6976 produces a long-lasting amnesia that is independent of the strength of the memory trace, suggesting that post-retrieval activation of hippocampal PKC is essential for persistence of spatial memory.
Assuntos
Hipocampo/enzimologia , Aprendizagem em Labirinto/fisiologia , Rememoração Mental/fisiologia , Proteína Quinase C/metabolismo , Percepção Espacial/fisiologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Aprendizagem da Esquiva/fisiologia , Carbazóis/administração & dosagem , Esquema de Medicação , Inibidores Enzimáticos/administração & dosagem , Hipocampo/efeitos dos fármacos , Indóis/administração & dosagem , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Rememoração Mental/efeitos dos fármacos , Microinjeções , Proteína Quinase C/antagonistas & inibidores , Ratos , Ratos Wistar , Percepção Espacial/efeitos dos fármacosRESUMO
Two major memory systems have been recognized over the years (Squire, in Memory and Brain, 1987): the declarative memory system, which is under the control of the hippocampus and related temporal lobe structures, and the procedural or habit memory system, which is under the control of the striatum and its connections (Mishkin et al., in Neurobiology of Learning by G Lynch et al., 1984; Knowlton et al., Science 273:1399, 1996). Most if not all learning tasks studied in animals, however, involve either the performance or the suppression of movement. Animals acquire connections between environmental or discrete sensory cues (conditioned stimuli, CSs) and emotionally or otherwise significant stimuli (unconditioned stimuli, USs). As a result, they learn to perform or to inhibit the performance of certain motor responses to the CS which, when learned well, become what can only be called habits (Mishkin et al., 1984): to regularly walk or swim to a place or away from a place, or to inhibit one or several forms of movement. These responses can be viewed as conditioned responses (CRs) and may sometimes be very complex. This is of course also seen in humans: people learn how to play on a keyboard in response to a mental or written script and perform the piano or write a text; with practice, the performance improves and eventually reaches a high criterion and becomes a habit, performed almost if not completely without awareness. Commuting to school in a big city in the shortest possible time and eschewing the dangers is a complex learning that children acquire to the point of near-perfection. It is agreed that the rules that connect the perception of the CS and the expression of the CR change from their first association to those that take place when the task is mastered. Does this change of rules involve a switch from one memory system to another? Are different brain systems used the first time one plays a sonata or goes to school as compared with the 100th time? Here we will comment on: 1) reversal learning in the Morris water maze (MWM), in which the declarative or spatial component of a task is changed but the procedural component (to swim) persists and needs to be re-linked with a different set of spatial cues; and 2) a series of observations on an inhibitory avoidance task that indicate that the brain systems involved change with further learning.
Assuntos
Corpo Estriado/fisiologia , Hipocampo/fisiologia , Memória , Vias Neurais/fisiologia , Animais , Aprendizagem da Esquiva/fisiologia , Humanos , Aprendizagem em LabirintoRESUMO
Inhibitory avoidance (IA) learning relies on the formation of an association between stepping down from a platform present in a certain context (conditioned stimulus; CS) with an aversive unconditioned stimulus (US; i.e. a footshock). A single CS-US pairing establishes a robust long-term memory expressed as an increase in step-down latency at testing. However, repeated retrieval of the avoidance response in the absence of the US induces extinction of IA memory. That is, recurring presentation of the CS alone results in a new learning indicating that the CS no longer predicts the US. Although the signaling pathways involved in the consolidation of IA and other fear-motivated memories have been profusely studied, little is known about the molecular requirements of fear memory extinction. Here we report that, as happens with its consolidation, extinction of IA long-term memory requires activity of the p38 subfamily of mitogen-activated protein kinases (MAPK) in the CA1 region of the dorsal hippocampus. Moreover, we found that inhibition of hippocampal p38MAPK blocked memory reacquisition after extinction without affecting either the increase in IA memory retention induced by a second training session or animal's locomotor/exploratory activity and anxiety state.
Assuntos
Aprendizagem da Esquiva/fisiologia , Extinção Psicológica/fisiologia , Hipocampo/enzimologia , Inibição Psicológica , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Comportamento Animal , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Comportamento Exploratório/efeitos dos fármacos , Extinção Psicológica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Imidazóis/farmacologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Piridinas/farmacologia , Ratos , Ratos Wistar , Tempo de Reação/efeitos dos fármacos , Fatores de TempoRESUMO
Wastewater from dairies and slaughterhouses contains high levels of fats and proteins that present low biodegradability. A large number of pretreatment systems are employed to remove oil and grease (O&G) to prevent a host of problems that may otherwise arise in the biological process, and reduce the efficiency of the treatment station. Problems caused by excessive O&G include a reduction in the cell-aqueous phase transfer rates, a sedimentation hindrance due to the development of filamentous microorganisms, development and flotation of sludge with poor activity, clogging and the emergence of unpleasant odors. Therefore the application of a pretreatment to hydrolyze and dissolve lipids may improve the biological degradation of fatty wastewaters, accelerating the process and improving time efficiency. However thus far, only a few studies describing the degradation of fats and oils by alkaline/acid/enzymatic hydrolysis have been reported; the treatment of effluents from several origins is a new and promising application for lipases. Among the strains that produce the hydrolytic enzymes studied, the fungus Penicillium restrictum is a particularly promising one. When cultivated in low-cost solid medium composed of agro-industrial waste, P. restrictum produces a pool of hydrolases capable of degrading the most complex organic compounds. This degradation enables a considerable increase in organic matter removal efficiency to be realized, which results in the attainment of a high-quality effluent in the subsequent biological treatment stage. Consequently, there is presently a wide variety of ongoing scientific investigation in the field of developing enzymatic hydrolysis processes to precede traditional biological treatment.
Assuntos
Gorduras/metabolismo , Indústria Alimentícia , Óleos/metabolismo , Purificação da Água , Biodegradação Ambiental , Fermentação , Hidrolases/metabolismo , Hidrólise , Penicillium/enzimologia , Eliminação de Resíduos Líquidos , Purificação da Água/normasRESUMO
The School of Chemistry Environmental Technology Laboratory generates 43.4 1 of effluent with low pH (0.7) and high contents of COD (1908 mgO2 l(-1)), phenol (132.1 mg l(-1)), sulfate (36700 mg l(-1)) and heavy metals (28.2 mg Hg l(-1); 82.1 mg Cr(total) l(-1); 30.8 mg Cu l(-1); 57.4 mg Fe(total) l(-1); 16.2 mg Al l(-1)) weekly. These data show that this effluent presents high toxicity for biological treatment, with a physical-chemical step being necessary before a biological step. Preliminary studies showed that the most toxic constituents of the effluent were sulfate, phenol and total chromium. In this work, a chemical precipitation step with sodium hydroxide or lime was evaluated for the toxicity reduction on anaerobic microbial consortium. These experiments were carried out with increasing concentrations of alkalis in the effluent in order to obtain pH initial values of 8-12. Similar results were obtained for COD (15-28%), turbidity (95-98%), phenol (13-24%) and total chromium (99.8-99.9%) removals in each condition studied with soda or lime. Sulfate was only removed by precipitation with lime, obtaining reductions from 84 to 88%. The toxicity on the anaerobic sludge was studied employing specific methanogenic activity (SMA) analysis of raw and treated effluent (after chemical precipitation step). The SMA experiments showed that chemical precipitation at pH 8 reduces the toxic effect of the effluent on anaerobic microbial consortium three times (with soda) and thirteen times (with lime). These results indicate that precipitation with lime is more efficient at toxicity removal, however the produced sludge volume is around two times higher than that produced with soda.
Assuntos
Bactérias Anaeróbias/efeitos dos fármacos , Bactérias Anaeróbias/metabolismo , Compostos de Cálcio/química , Metais Pesados/toxicidade , Óxidos/química , Hidróxido de Sódio/química , Sulfatos/toxicidade , Poluentes da Água/toxicidade , Anaerobiose , Precipitação Química , Concentração de Íons de Hidrogênio , Metano/metabolismo , Esgotos/microbiologia , Poluentes da Água/químicaRESUMO
The efficiency of an anaerobic biological treatment for the reduction of essential contaminants of produced water from an offshore oilfield was investigated using a microbial consortium enriched with sulphate-reducing bacteria (SRB). Experiments were conducted in a bench bioreactor at 35 degrees C, 250 rpm, with intermittent purges of N2 gas in order to establish anaerobic conditions and to remove the H2S generated. The results showed that pH control effectively influenced the activity of the anaerobic bacteria leading to COD removal of 57%. Meanwhile, pH control was found to have no influence on the removal efficiencies of oil and grease and total phenols. In all experiments, removals of oil and grease and total phenols of 60% and 58-67%, respectively, were obtained after a 15-day process. In studies carried out with biomass reuse the reductions obtained were 61% for oil and grease and 78% for total phenols over the same period. Such results point to the technical feasibility of anaerobic biodegradation for oilfield wastewater treatment.
Assuntos
Bactérias Anaeróbias/crescimento & desenvolvimento , Bactérias Anaeróbias/metabolismo , Petróleo/metabolismo , Bactérias Redutoras de Enxofre/metabolismo , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Reatores Biológicos/microbiologia , Resíduos Industriais , Fenóis/análiseRESUMO
The rat hippocampus plays a crucial role in the consolidation of a variety of memories, including that for a one trial inhibitory avoidance learning task in which stepping down from a platform is associated with a footshock. Here we show that this is the case regardless of the intensity of the footshock used and hence, of the strength of the learned response. However, additional learning produced by a second training session in this task does not involve the hippocampus but, instead, the striatum. Memory consolidation of the second trial requires glutamate alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate, N-methyl-D-aspartate and metabotropic receptors, activation of signaling pathways, gene expression and protein synthesis in the striatum, as are required in the hippocampus during memory consolidation of the first trial.
Assuntos
Corpo Estriado/fisiologia , Hipocampo/fisiologia , Aprendizagem/fisiologia , Retenção Psicológica/efeitos dos fármacos , Valina/análogos & derivados , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Comportamento Animal , Benzilaminas/farmacologia , Corpo Estriado/efeitos dos fármacos , Diclororribofuranosilbenzimidazol/farmacologia , Eletrochoque/efeitos adversos , Inibidores Enzimáticos/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Extinção Psicológica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Aprendizagem/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Quinoxalinas/farmacologia , Ratos , Ratos Wistar , Tempo de Reação/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/agonistas , Receptores de N-Metil-D-Aspartato/fisiologia , Estatísticas não Paramétricas , Sulfonamidas/farmacologia , Fatores de Tempo , Valina/farmacologiaRESUMO
The white rot fungus Trametes versicolor was applied to the decolourisation of three synthetic textile dyes in the presence and absence of glucose. Different initial dye concentrations were tested and approximately 97% decolourisation was achieved. It was found that fungal metabolism induced by the glucose as well as the pH play an important role in the decolourisation process. This treatment was also applied to a real wastewater from a textile industry-dyeing sector leading to 92% decolourisation.
Assuntos
Basidiomycota/fisiologia , Indústria Têxtil , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Concentração de Íons de HidrogênioRESUMO
A new procedure to mitigate the environmental impacts and reduce the cost of disposal of oil slurry is present in this paper. Waste from the petroleum industry has a high environmental impact. Systems for oil-water separation have been used to mitigate the contamination potential of these types of effluents. At the outlet of these systems, the oil is skimmed-off the surface, while the slurry is removed from the base. Due to the high concentration of contaminants, the disposal of this slurry is an environmentally hazardous practice. Usually this type of waste is disposed of in tanks or landfills after removal from the industrial plant. Basically, the proposed procedure utilizes drying beds with geotextile filters to both reduce the water content in the slurry and obtain a less contaminated effluent. Laboratory tests were carried out to simulate the drying system. Four types of filters were analyzed: two non-woven geotextiles, one woven geotextile, and a sand filter.
Assuntos
Óleos Combustíveis/análise , Resíduos Perigosos/prevenção & controle , Eliminação de Resíduos/instrumentação , Eliminação de Resíduos/métodos , Têxteis , Dessecação , Filtração/instrumentação , Água/químicaRESUMO
Using 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-D]pyrimidine (PP2), a specific inhibitor of the Src family of tyrosine kinases, here we show a direct involvement of these enzymes in memory formation and recall. When infused into the CA1 region of the dorsal hippocampus, immediately or 30 min after training rats in a one-trial inhibitory avoidance task, PP2 but not its inactive analog 4-amino-7-phenylpyrazol[3,4-D]pyrimidine (PP3), blocked short- (STM) and long-term memory (LTM) formation, as tested 2 or 24 h post-training, respectively. PP2 had no effect on STM when given at 60 min post-training or on LTM when administered at 60, 120 or 180 min after the training session, but blocked memory recall when infused into CA1 15 min before a LTM expression test. Hence, activity of the Src family of tyrosine kinases is required in the CA1 region of the rat dorsal hippocampus for the normal formation and retrieval of one-trial inhibitory avoidance memory.
Assuntos
Aprendizagem da Esquiva , Rememoração Mental/fisiologia , Quinases da Família src/farmacologia , Animais , Hipocampo/fisiologia , Masculino , Ratos , Ratos WistarRESUMO
Ultrasonication for the extraction of activated sludge exopolymers was evaluated by total cell count, exopolymer extraction and transmission electron microscopy (TEM). A high deflocculation was achieved after 30 s of sonication in PBS (phosphate-buffered saline). TEM showed that cell lysis was minimal only when sludges were sonicated for 30 s. For sludges sonicated for 30, 90 and 420 s and stained with Ruthenium Red, exopolymers were not extracted on a large scale without considerable cell lysis. Sludges sonicated for 30 s in EDTA gave a larger fraction of damaged cells and also showed copious amounts of attached exopolymers.
Assuntos
Bactérias Aeróbias/metabolismo , Bactérias Aeróbias/efeitos da radiação , Biofilmes/crescimento & desenvolvimento , Biofilmes/efeitos da radiação , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/isolamento & purificação , Esgotos/microbiologia , Sonicação , Bactérias Aeróbias/crescimento & desenvolvimento , Bactérias Aeróbias/ultraestrutura , Reatores Biológicos/microbiologia , Agregação Celular/efeitos da radiação , Técnicas de Cultura de Células/métodos , Divisão Celular/efeitos da radiação , Relação Dose-Resposta à RadiaçãoRESUMO
Several lines of evidence suggest that glutamate receptors are involved in memory processing. To examine the role of non-N-methyl-D-aspartate (non-NMDA) glutamate receptors on memory consolidation, rats were bilaterally implanted with cannulae aimed at the CA1 region of the dorsal hippocampus (CA1), entorhinal cortex (ENTO), posterior parietal cortex (PPC) or the basolateral nucleus of the amygdala (BLA), and trained in a one-trial step-down inhibitory avoidance task. At different times after training, the alpha-amino 3-hydroxy-5 methyl 4-isoxazole propionate (AMPA) receptor blocker, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) (1.0 microg/side), or the metabotropic type-I receptor antagonist, 2-amino-3-phosphonopropionic acid (AP3) (1.0 microg/side), were infused into the above-mentioned structures. CNQX produced retrograde amnesia when infused into BLA or CA1 0, 30, 90 or 180 min post-training but not at later times. AP3 blocked memory consolidation when administered into CA1 0, 30 or 180 min post-training, while in BLA, it was amnestic only when given 0 or 30 min after the training session. CNQX and AP3 had no effect on memory when administered into ENTO or PPC at any time. Our data suggest that the consolidation of the avoidance memory requires intact non-NMDA receptor function in the hippocampus and the basolateral nucleus of the amygdala, but not necessarily in the entorhinal and parietal cortex, for long periods after training.
Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Agonistas de Aminoácidos Excitatórios/farmacologia , Ácido Caínico/farmacologia , Memória/efeitos dos fármacos , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/farmacologia , Tonsila do Cerebelo/efeitos dos fármacos , Animais , Córtex Entorrinal/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Masculino , Lobo Parietal/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
This work reports the results of experiments carried out in a sequencing batch reactor (SBR) operated under 24 hour cycles, treating an effluent containing a mixture of oil field wastewater and sewage, in different percentages. The removal of phenols, ammonium and COD was monitored in several experimental runs, varying the dilution degree of the oilfield wastewater (10 to 45% v/v). The volatile suspended solids (VSS) content in the reactor was also monitored and the protein (PTN) and polysaccharide (PS) contents of the suspended biomass were determined. The removal of ammonium and phenols did not vary significantly in the experimental runs, attaining average values of 95% and 65%, respectively. COD removal efficiencies in the range of 30 to 50% were attained in the experiments carried out with dilution percentages of 45 and 35% (v/v) respectively. An experiment carried out with a lower proportion of produced water (15% v/v), keeping the salinity level corresponding to a higher proportion of industrial effluent (45% v/v), led to an improvement in the COD removal, indicating that the recalcitrance of the organic compounds found in the effluent is the main cause ofthe moderate COD removal efficiencies attained in the SBR system. With regard to the composition of the microbial flocs, no significant variation was observed in the PS/PTN, PS/VSS and PTN/VSS ratios when the effluent composition changed (increased salinity and levels of organic material).
Assuntos
Petróleo , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Reatores Biológicos , Floculação , Resíduos Industriais , Compostos Orgânicos/metabolismo , Oxigênio/análise , Oxigênio/metabolismo , Cloreto de Sódio , VolatilizaçãoRESUMO
Several lines of evidence indicate that glutamate NMDA receptors are critically involved in long-term potentiation (LTP) and in certain forms of learning. It was previously demonstrated that memory formation of an inhibitory avoidance task in chick is specifically associated with an increase in the density of NMDA receptor in selected brain regions. Here we report on the effect of a one trial inhibitory avoidance training in rats, a hippocampal-dependent learning task, on the levels of different subunits of the glutamate NMDA receptor in synaptic plasma membranes (SPM) isolated from the hippocampus. Training rats on a one trial inhibitory avoidance task results in a rapid, transient and selective increase (+33%, p < 0.05) in NMDA NRI subunit expression in hippocampal SPM of rats sacrificed 30 min posttraining. No changes were observed at 0 or 120 min after training or in shocked animals in comparison to naive control rats. In addition, no training-associated increase in the levels of NMDA NR2A and NR2B or AMPA GluR 2/3 subunits was observed at any timepoint tested. In conclusion, the present findings support the hypothesis that alterations in expression of synaptic NMDA NR1 subunits in the hippocampus are specifically associated with memory formation of an inhibitory avoidance task and strongly suggest that hippocampal NMDA receptors are crucially involved in the neural mechanisms underlying certain forms of learning.
Assuntos
Aprendizagem da Esquiva/fisiologia , Hipocampo/fisiologia , Receptores de N-Metil-D-Aspartato/metabolismo , Membranas Sinápticas/metabolismo , Animais , Eletrochoque , Masculino , Ratos , Ratos Wistar , Receptores de AMPA/metabolismo , Valores de Referência , Fatores de TempoRESUMO
The Fos family of transcription factors has been repeatedly shown to participate in the long-term neural responses associated with a variety of physiological stimuli, including activity-dependent plastic processes. Quite recently, several transcription factors have been found in synaptic regions, localized in dendrites and presynaptic terminals. Here we show that the transcription factor Fos-related antigen-1 (Fra-1) was detected in synaptosomes (Syn) and synaptic plasma membrane (SPM) fractions from the rat cerebral cortex and hippocampus as a single band migrating with M(r) 42-43 kDa. The 55-kDa c-Fos protein was also detected in syn and SPM fractions. Conversely, the inducible 62-65-kDa c-Fos is present in nuclear fractions from metrazole-treated animals (positive control), but not in Syn or SPM fractions. Furthermore, no Fra-2, Fos B or c-Jun immunoreactivities were detected in these same synaptic regions. DNA-mobility shift assays showed the presence of specific AP-1 binding activity in synaptic protein extracts. Immunoelectronmicroscopic analysis of cortical and hippocampal tissues revealed that Fra-1 and Fos-like immunoreactivities are localized in association with presynaptic plasma membranes. One trial inhibitory avoidance training, a hippocampal-dependent task, is associated with a time-dependent decrease (-31%) in Fra-1, but not in 55-kDa c-Fos, levels in hippocampal SPM fractions. In hippocampal homogenates, we do not detect significant changes in Fra-1 immunoreactivity, suggesting that this behavioural experience is probably accompanied by a subcellular redistribution of Fra-1 protein. These results suggest that Fra-1 may participate in the communication between synapse and the nucleus and in experience-dependent hippocampal plasticity.