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Genetic abnormalities affecting glutamate receptors are central to excitatory overload-driven neuronal mechanisms that culminate in seizures, making them pivotal targets in epilepsy research. Increasingly used to advance this field, the genetically audiogenic seizure hamster from Salamanca (GASH/Sal) exhibits generalized seizures triggered by high-intensity acoustic stimulation and harbors significant genetic variants recently identified through whole-exome sequencing. Here, we addressed the influence of the missense single-nucleotide polymorphism (C9586732T, p.His289Tyr) in the glutamate receptor ionotropic kainate-1 (Grik1) gene and its implications for the GASH/Sal seizure susceptibility. Using a protein 3D structure prediction, we showed a potential effect of this sequence variation, located in the amino-terminal domain, on the stability and/or conformation of the kainate receptor subunit-1 protein (GluK1). We further employed a multi-technique approach, encompassing gene expression analysis (RT-qPCR), Western blotting, and immunohistochemistry in bright-field and confocal fluorescence microscopy, to investigate critical seizure-associated brain regions in GASH/Sal animals under seizure-free conditions compared to matched wild-type controls. We detected disruptions in the transcriptional profile of the Grik1 gene within the audiogenic seizure-associated neuronal network. Alterations in GluK1 protein levels were also observed in various brain structures, accompanied by an unexpected lower molecular weight band in the inferior and superior colliculi. This correlated with substantial disparities in GluK1-immunolabeling distribution across multiple brain regions, including the cerebellum, hippocampus, subdivisions of the inferior and superior colliculi, and the prefrontal cortex. Notably, the diffuse immunolabeling accumulated within perikarya, axonal fibers and terminals, exhibiting a prominent concentration in proximity to the cell nucleus. This suggests potential disturbances in the GluK1-trafficking mechanism, which could subsequently affect glutamate synaptic transmission. Overall, our study sheds light on the genetic underpinnings of seizures and underscores the importance of investigating the molecular mechanisms behind synaptic dysfunction in epileptic neural networks, laying a crucial foundation for future research and therapeutic strategies targeting GluK1-containing kainate receptors.

Epilepsy is a neurological disorder characterized by abnormal neuronal excitability, with glutamate playing a key role as the predominant excitatory neurotransmitter involved in seizures. Animal models of epilepsy are crucial in advancing epilepsy research by faithfully replicating the diverse symptoms of this disorder. In particular, the GASH/Sal (genetically audiogenic seizure-prone hamster from Salamanca) model exhibits seizures resembling human generalized tonic-clonic convulsions. A single nucleotide polymorphism (SNP; C9586732T, p.His289Tyr) in the Grik1 gene (which encodes the kainate receptor GluK1) has been previously identified in this strain. The H289Y mutation affects the amino-terminal domain of GluK1, which is related to the subunit assembly and trafficking. We used confocal microscopy in Xenopus oocytes to investigate how the H289Y mutation, compared to the wild type (WT), affects the expression and cell-surface trafficking of GluK1 receptors. Additionally, we employed the two-electrode voltage-clamp technique to examine the functional effects of the H289Y mutation. Our results indicate that this mutation increases the expression and incorporation of GluK1 receptors into an oocyte’s membrane, enhancing kainate-evoked currents, without affecting their functional properties. Although further research is needed to fully understand the molecular mechanisms responsible for this epilepsy, the H289Y mutation in GluK1 may be part of the molecular basis underlying the seizure-prone circuitry in the GASH/Sal model.

The GASH/Sal (Genetic Audiogenic Seizure Hamster, Salamanca) is a model of audiogenic seizures with the epileptogenic focus localized in the inferior colliculus (IC). The sound-induced seizures exhibit a short latency (7–9 s), which implies innate protein disturbances in the IC as a basis for seizure susceptibility and generation. Here, we aim to study the protein profile in the GASH/Sal IC in comparison to controls. Protein samples from the IC were processed for enzymatic digestion and then analyzed by mass spectrometry in Data-Independent Acquisition mode. After identifying the proteins using the UniProt database, we selected those with differential expression and performed ontological analyses, as well as gene-protein interaction studies using bioinformatics tools. We identified 5254 proteins; among them, 184 were differentially expressed proteins (DEPs), with 126 upregulated and 58 downregulated proteins, and 10 of the DEPs directly related to epilepsy. Moreover, 12 and 7 proteins were uniquely found in the GASH/Sal or the control. The results indicated a protein profile alteration in the epileptogenic nucleus that might underlie the inborn occurring audiogenic seizures in the GASH/Sal model. In summary, this study supports the use of bioinformatics methods in proteomics to delve into the relationship between molecular-level protein mechanisms and the pathobiology of rodent models of audiogenic seizures.

Polyurethanes (PU) are the sixth most produced plastics with around 18-million tons in 2016, but since they are not recyclable, they are burned or landfilled, generating damage to human health and ecosystems. To elucidate the mechanisms that landfill microbial communities perform to attack recalcitrant PU plastics, we studied the degradative activity of a mixed microbial culture, selected from a municipal landfill by its capability to grow in a water PU dispersion (WPUD) as the only carbon source, as a model for the BP8 landfill microbial community. The WPUD contains a polyether-polyurethane-acrylate (PE-PU-A) copolymer and xenobiotic additives (N-methylpyrrolidone, isopropanol and glycol ethers). To identify the changes that the BP8 microbial community culture generates to the WPUD additives and copolymer, we performed chemical and physical analyses of the biodegradation process during 25 days of cultivation. These analyses included Nuclear magnetic resonance, Fourier transform infrared spectroscopy, Thermogravimetry, Differential scanning calorimetry, Gel permeation chromatography, and Gas chromatography coupled to mass spectrometry techniques. Moreover, for revealing the BP8 community structure and its genetically encoded potential biodegradative capability we also performed a proximity ligation-based metagenomic analysis. The additives present in the WPUD were consumed early whereas the copolymer was cleaved throughout the 25-days of incubation. The analysis of the biodegradation process and the identified biodegradation products showed that BP8 cleaves esters, C-C, and the recalcitrant aromatic urethanes and ether groups by hydrolytic and oxidative mechanisms, both in the soft and the hard segments of the copolymer. The proximity ligation-based metagenomic analysis allowed the reconstruction of five genomes, three of them from novel species. In the metagenome, genes encoding known enzymes, and putative enzymes and metabolic pathways accounting for the biodegradative activity of the BP8 community over the additives and PE-PU-A copolymer were identified. This is the first study revealing the genetically encoded potential biodegradative capability of a microbial community selected from a landfill, that thrives within a WPUD system and shows potential for bioremediation of polyurethane- and xenobiotic additives-contamitated sites.

The need to implement sustainable and productive systems compatible with populations leads to the elimination of burning as a practice associated with sugarcane harvesting. This work is part of a study where two sugarcane production systems were compared: a) with trash blanket (mulching) and b) without trash blanket (burnt residue). Macroplots were established in a commercial field planted with LCP 85-384, in Albarracín (Cruz Alta, Tucumán, Argentina). A split-plot experimental design with three replicates was used. Each plot consisted of five 30-m furrows. Two crop cycles were considered: 2006/2007 and 2007/2008. From sugar cane harvest onwards, soil water content at 20-cm and 40-cm depth, soil temperature at 15-cm depth, stalk number and basic infiltration rate were periodically determined. Cane yielding (t/ha and t/100-m row) was estimated at harvesting time using stalk number and weight data. There was a higher water content in the treatment under trash blanket management for the 2007/2008 cycle, but no differences were found between treatments in the 2006/2007 cycle. These results depended on rainfall amount and distribution. Soil temperature was higher in the treatment without trash blanket and this situation was registered until canopy closure. Stalk population dynamics showed a higher stalk number during tillering peak in the treatment with trash blanket. At harvesting time this trend was evident, but the difference was significant only in 2007/2008. Sugarcane production per hectare was 12% and 55% higher in the treatment with trash blanket in 2006/2007 and 2007/2008, respectively.La necesidad de implementar sistemas productivos sustentables y amigables con las poblaciones vecinas a los campos conduce a la eliminación de la quema como práctica asociada a la cosecha de la caña de azúcar. Este trabajo forma parte de un estudio donde se compararon dos sistemas de producción de caña de azúcar: a) con cobertura de residuos de cosecha ("mulching") y b) sin cobertura de residuos de cosecha (residuo quemado). Se establecieron macroparcelas en un lote comercial implantado con el cultivar LCP 85-384, en Albarracín, Cruz Alta, Tucumán, R. Argentina. El diseño experimental fue de parcelas divididas con tres repeticiones, estando cada parcela formada por cinco surcos de 30 m. Se evaluaron dos ciclos agrícolas: 2006/2007 y 2007/2008. A partir de la cosecha, se determinaron periódicamente la humedad del suelo a 20 cm y 40 cm de profundidad, la temperatura de suelo a 15 cm de profundidad, la infiltración básica y el número de tallos. Al momento de cosecha, se determinaron número y peso de tallos, a partir de los cuales se estimaron las toneladas de caña por surco y por hectárea. La humedad del suelo resultó mayor en el tratamiento con cobertura de residuos para el ciclo 2007/2008, no así para el ciclo 2006/2007, donde no hubo diferencias entre tratamientos. Este comportamiento dependió de la cantidad y distribución de las lluvias. La temperatura del suelo fue mayor en el tratamiento sin cobertura, situación que se mantuvo hasta el cierre del cañaveral. La dinámica de la población de tallos mostró un número de tallos mayor para el tratamiento con cobertura en el pico del macollaje. A cosecha se mantuvo esta tendencia, pero la diferencia solo fue significativa en 2007/2008. La producción de caña por hectárea fue un 12% y un 55% mayor en el tratamiento con cobertura en 2006/2007 y 2007/2008, respectivamente.

Low environmental impact production systems are a major concern in agroindustry and society, with food and sugarcane production being one of the areas where sustainability is a high priority. Green cane harvesting emerges as an important alternative for a cleaner production system, since it excludes the burning of residues, conserves soil and insolves the possibility of energy generation. An estimation of potential sugarcane available trash is very important in order to define management strategies. A research was carried out to determine the amount of dry trash available in cane fields before (SPT) and after green cane harvesting (SFT). Also, the relationship between SPT and SFT was studied in order to validate the precision of SPT as an SFT predictor using green cane combine harvesting for the main cultivated varieties in the sugarcane-growing area of Tucumán (LCP 85-384, TUCCP 77-42, CP 65-357 and RA 87-3). An increase in SPT was associated to cane yielding/ha, ranging from 6.9 to 16.0 t/ha of SPT for 32 to 104 t/ha of cane yielding. LCP 85-384 and CP 65-357 produced the highest amount of dry trash before harvest, while TUCCP 77-42 produced the least for similar cane yielding. Simultaneously the DT/CY ratio decreased with a mean value around 16% of cane yield and its use for estimating SPT was limited, as low coefficients of determination highlight. SPT appropriately predicted SFT under green cane combine harvesting conditions and the former one could be estimated using cane yielding/ha.La implementación de sistemas productivos con bajo impacto ambiental es una preocupación tanto para la agroindustria como para la sociedad, resultando la producción de azúcar una de las áreas donde la sustentabilidad es un objetivo prioritario y alcanzable. La cosecha en verde de la caña de azúcar aparece como una importante alternativa para conformar sistemas de producción más limpios, prescindiendo de la quema de material vegetal y residuos de cosecha, conservando el suelo y ofreciendo una posibilidad para la generación de energía. Una estimación del potencial de residuos disponible de la caña de azúcar cobra gran relevancia en el momento de definir estrategias de manejo. Se realizó un estudio para determinar la cantidad de biomasa residual disponible en los cañaverales en forma previa (SPT) y posterior (SFT) a la cosecha mecanizada en verde para las principales variedades cultivadas en la provincia de Tucumán (LCP 85-384, TUCCP 77-42, CP 65-357 y RA 87-3). Además, se estudió la relación entre SPT y SFT a fin de validar la precisión de SPT como predictor de SFT en el caso de la cosecha integral en verde. El incremento del SPT estuvo asociado al mayor rendimiento cultural/ha, registrándose valores del 6,9 a 16,0 t/ha de biomasa residual para rendimientos culturales de 32 a 104 t/ha. LCP 85-384 y CP 65-357 produjeron el mayor SPT, mientras que TUCCP 77-42 generó la menor cantidad para niveles similares de rendimiento cultural. La relación SPT/CY disminuyó y el promedio general fue del 16% del rendimiento cultural, aunque su uso para estimar SPT fue limitado, como señalan los bajos coeficientes de determinación. SPT predijo adecuadamente SFT para el caso de la cosecha integral en verde, y el primero puede ser estimado adecuadamente empleando el rendimiento cultural/ha.

En Tucumán, Argentina, una práctica generalizada en el cultivo de la caña de azúcar es la quema de cañaverales previa a la cosecha o la de sus residuos en poscosecha. La Comisión Nacional de Actividades Espaciales (CONAE), ofrece una herramienta para la teledetección de focos de fuego a través de “mapas de focos de calor” generados por los sistemas satelitales TERRA y AQUA MODIS pertenecientes a la NASA. El propósito de este trabajo fue realizar una aplicación de esta información para el registro de focos de fuego en el área cañera de Tucumán, generando una base de datos y estadísticas de la ocurrencia de quema de cañaverales para los períodos de zafra durante los años 2004, 2005 y 2006. Además, se efectuaron validaciones en campo para evaluar su potencial empleo como un sistema de monitoreo de fuegos en áreas agrícolas y otros recursos naturales. En todos los casos, septiembre fue el mes con la mayor ocurrencia de fuegos y Cruz Alta, el departamento con el mayor registro de focos de fuego. Además se observó una tendencia creciente en el uso de la quema previa o posterior a la cosecha.A generalized agricultural practice in Tucumán, Argentina, is pre-harvest sugarcane burning or burning of its post harvest residues. The Comisión Nacional de Actividades Espaciales (CONAE) offers a tool for fire ocurrence teledetection using thermal anomalies maps, generated by NASA TERRA and AQUA MODIS satellite systems. This information was used for fire registration on sugarcane cultivation area, generating a database and statistics of sugarcane burning during the harvesting period from 2004 to 2006 in Tucumán. Moreover, an attempt to validate the potential use of this tool as a fire monitoring system in agriculture and natural resources areas was carried out. September was the month with major number of fire occurrences in all considered cases and Cruz Alta was the location with most fire records. The use of pre or post harvest burning evidenced a tendency to increase.