Cell-type specific binocular interactions in mouse visual thalamus.

Projections from each eye are segregated in separate domains within the dorsal lateral geniculate nucleus (dLGN). Yet, in vivo studies indicate that the activity of single dLGN neurons can be influenced by visual stimuli presented to either eye. In this study we explored whether intrinsic circuits mediate binocular interactions in the mouse dLGN. We employed dual color optogenetics in vitro to selectively activate input from each eye and recorded synaptic responses in thalamocortical (relay) cells as well as inhibitory interneurons, which have extensive dendritic arbors that are not confined to eye specific domains. While most relay cells received monocular retinal input, most interneurons received binocular retinal input; consequently, the majority of dLGN relay cells received binocular retinogeniculate-evoked inhibition. Moreover, in recordings from adjacent pairs of relay cells and interneurons, the most common relationship observed was binocular excitation of interneurons paired with binocular inhibition of adjacent relay cells. Finally, we found that dLGN interneurons are interconnected, displaying both monocular and binocular inhibition in response to retinal activation. In sum, our results indicate that geniculate interneurons provide one of the first locations where signals from the two eyes can be compared, integrated, and adjusted before being transmitted to cortex, shedding new light on the role of the thalamus in binocular vision. Highlights: In vitro dual color optogenetics examined convergence of eye-specific retinal inputs to thalamocortical (relay) cells and interneurons in the dLGNThe majority of relay cells receive monocular excitatory retinogeniculate input while the majority of interneurons receive binocular inputBinocular relay cells are located in and around the ipsilateral patch whereas binocular interneurons are distributed throughout the dLGNThe majority of relay cells receive binocular retinogeniculate-evoked inhibitiondLGN interneurons are interconnected, receiving both monocular and binocular retinogeniculate-evoked inhibition.

Development of reciprocal connections between the dorsal lateral geniculate nucleus and the thalamic reticular nucleus.

The thalamic reticular nucleus (TRN) serves as an important node between the thalamus and neocortex, regulating thalamocortical rhythms and sensory processing in a state dependent manner. Disruptions in TRN circuitry also figures prominently in several neurodevelopmental disorders including epilepsy, autism, and attentional defects. An understanding of how and when connections between TRN and 1st order thalamic nuclei, such as the dorsal lateral geniculate nucleus (dLGN), develop is lacking. We used the mouse visual thalamus as a model system to study the organization, pattern of innervation and functional responses between TRN and the dLGN. Genetically modified mouse lines were used to visualize and target the feedforward and feedback components of these intra-thalamic circuits and to understand how peripheral input from the retina impacts their development.Retrograde tracing of thalamocortical (TC) afferents through TRN revealed that the modality-specific organization seen in the adult, is present at perinatal ages and seems impervious to the loss of peripheral input. To examine the formation and functional maturation of intrathalamic circuits between the visual sector of TRN and dLGN, we examined when projections from each nuclei arrive, and used an acute thalamic slice preparation along with optogenetic stimulation to assess the maturation of functional synaptic responses. Although thalamocortical projections passed through TRN at birth, feedforward axon collaterals determined by vGluT2 labeling, emerged during the second postnatal week, increasing in density through the third week. Optogenetic stimulation of TC axon collaterals in TRN showed infrequent, weak excitatory responses near the end of week 1. During weeks 2-4, responses became more prevalent, grew larger in amplitude and exhibited synaptic depression during repetitive stimulation. Feedback projections from visual TRN to dLGN began to innervate dLGN as early as postnatal day 2 with weak inhibitory responses emerging during week 1. During week 2-4, inhibitory responses continued to grow larger, showing synaptic depression during repetitive stimulation. During this time TRN inhibition started to suppress TC spiking, having its greatest impact by week 4-6. Using a mutant mouse that lacks retinofugal projections revealed that the absence of retinal input led to an acceleration of TRN innervation of dLGN but had little impact on the development of feedforward projections from dLGN to TRN. Together, these experiments reveal how and when intrathalamic connections emerge during early postnatal ages and provide foundational knowledge to understand the development of thalamocortical network dynamics as well as neurodevelopmental diseases that involve TRN circuitry.

In Vitro Gamma Mutagenesis Techniques in Rice (Oryza sativa L. var. Lazarroz FL).

Gamma radiation (60Co)-induced mutagenesis offers an alternative to develop rice lines by accelerating the spontaneous mutation process and increasing the pool of allelic variants available for breeding. Ionizing radiation works by direct or indirect damage to DNA and subsequent mutations. The technique can take advantage of in vitro protocols to optimize resources and accelerate the development of traits. This is achieved by exposing mutants to a selection agent of interest in controlled conditions and evaluating large numbers of plants in reduced areas. This chapter describes the protocol for establishing gamma radiation dosimetry and in vitro protocols for optimization at the laboratory level using seeds as the starting material, followed by embryogenic cell cultures, somatic embryogenesis, and regeneration. The final product of the protocol is a genetically homogeneous population of Oryza sativa that can be evaluated for breeding against abiotic and biotic stresses.

Novel strains of Actinobacteria associated with neotropical social wasps (Vespidae; Polistinae, Epiponini) with antimicrobial potential for natural product discovery.

Antimicrobial resistance has been considered a public health threat. The World Health Organization has warned about the urgency of detecting new antibiotics from novel sources. Social insects could be crucial in the search for new antibiotic metabolites, as some of them survive in places that favor parasite development. Recent studies have shown the potential of social insects to produce antimicrobial metabolites (e.g. ants, bees, and termites). However, most groups of social wasps remain unstudied. Here, we explored whether Actinobacteria are associated with workers in the Neotropical Social Wasps (Epiponini) of Costa Rica and evaluated their putative inhibitory activity against other bacteria. Most isolated strains (67%) have antagonistic effects, mainly against Bacillus thuringensis and Escherichia coli ATCC 25992. Based on genome analysis, some inhibitory Actinobacteria showed biosynthetic gene clusters (BGCs) related to the production of antimicrobial molecules such as Selvamycin, Piericidin A1, and Nystatin. The Actinobacteria could be associated with social wasps to produce antimicrobial compounds. For these reasons, we speculate that Actinobacteria associated with social wasps could be a novel source of antimicrobial compounds, mainly against Gram-negative bacteria.

VATS Uniportal, masterclass Guatemala / VATS Uniportal, masterclass Guatemala

En las dos últimas décadas la evolución de la cirugía mínimamente invasiva del tórax ha transmutado de un abordaje de tres puertos, siguiendo dos puertos hasta llegar a puerto único, conocido también como VATS Uniportal, procurando un confort mucho mejor para el paciente y resultados quirúrgicos similares. Objetivos. Presentar la técnica quirúrgica de VATS Uniportal en un hospital nacional, efectuadas por un experto internacional en este campo. Pacientes y Métodos. Se presentan dos casos clínicos quirúrgicos: El de una paciente con Miastenia Gravis a quien se le realizó timectomía por abordaje sub-xifoideo y otra paciente, a quien se le completó una lobectomía inferior derecha por hallazgos de patología posterior a la resección de un nódulo pulmonar solitario, reportado como cáncer primario de pulmón. Conclusiones. La técnica de cirugía mínimamente invasiva, VATS Uniportal, ofrece grandes beneficios para el paciente, tanto estéticos como funcionales y su aprendizaje es posible con la transmisión de conocimientos y experiencias directa con la presencia del experto o indirectas a través de la información publicada. (AU)

In the last two decades, the evolution of minimally invasive chest surgery has transmuted from a three-port approach, following two ports until reaching a single port, also known as VATS Uniportal, seeking much better comfort for the patient and similar surgical results. Objective. Present the VATS Uniportal surgical technique in a national hospital, performed by an international expert in this field. Patients and Methods. Two surgical clinical cases are presented: that of a patient with Myasthenia Gravis who underwent thymectomy through the sub-xiphoid approach and another patient, who underwent a right lower lobectomy due to findings of pathology after the resection of a pulmonary nodule. solitary, reported as primary lung cancer. Conclusions. The minimally invasive surgery technique, VATS Uniportal, offers great benefits for the patient, both aesthetic and functional and its learning is possible with the transmission of knowledge and experiences directly with the presence of the expert or indirectly through published information. (AU)