Pain-induced adaptations in the claustro-cingulate pathway.

Persistent pain is a prevalent medical concern correlating with a hyperexcitable anterior cingulate cortex (ACC). Its activity is modulated by inputs from several brain regions, but the maladjustments that these afferent circuits undergo during the transition from acute to chronic pain still require clarification. We focus on ACC-projecting claustrum (CLAACC) neurons and their responses to sensory and aversive stimuli in a mouse model of inflammatory pain. Using chemogenetics, in vivo calcium imaging, and ex vivo electrophysiological approaches, we reveal that suppression of CLAACC activity acutely attenuates allodynia and that the claustrum preferentially transmits aversive information to the ACC. With prolonged pain, a claustro-cingulate functional impairment develops, which is mediated by a weakened excitatory drive onto ACC pyramidal neurons, resulting in a diminished claustral influence on the ACC. These findings support an instrumental role of the claustrum in the processing of nociceptive information and its susceptibility to persistent pain states

Principles of nociceptive coding in the anterior cingulate cortex.

The perception of pain is a multidimensional sensory and emotional/affective experience arising from distributed brain activity. However, the involved brain regions are not specific for pain. Thus, how the cortex distinguishes nociception from other aversive and salient sensory stimuli remains elusive. Additionally, the resulting consequences of chronic neuropathic pain on sensory processing have not been characterized. Using in vivo miniscope calcium imaging with cellular resolution in freely moving mice, we elucidated the principles of nociceptive and sensory coding in the anterior cingulate cortex, a region essential for pain processing. We found that population activity, not single-cell responses, allowed discriminating noxious from other sensory stimuli, ruling out the existence of nociception-specific neurons. Additionally, single-cell stimulus selectivity was highly dynamic over time, but stimulus representation at the population level remained stable. Peripheral nerve injury-induced chronic neuropathic pain led to dysfunctional encoding of sensory events by exacerbation of responses to innocuous stimuli and impairment of pattern separation and stimulus classification, which were restored by analgesic treatment. These findings provide a novel interpretation for altered cortical sensory processing in chronic neuropathic pain and give insights into the effects of systemic analgesic treatment in the cortex

Environmental enrichment promotes resilience to neuropathic pain-induced depression and correlates with decreased excitability of the anterior cingulate cortex.

Depression is a common comorbidity of chronic pain with many patients being affected. However, efficient pharmacological treatment strategies are still lacking. Therefore, it is desirable to find additional alternative approaches. Environmental enrichment has been suggested as a method to alleviate pain-induced depression. However, the neuronal mechanisms of its beneficial effects are still elusive. The anterior cingulate cortex (ACC) plays a central role in processing pain-related negative affect and chronic pain-induced plasticity in this region correlates with depressive symptoms. We studied the consequences of different durations of environmental enrichment on pain sensitivity and chronic pain-induced depression-like behaviors in a mouse model of neuropathic pain. Furthermore, we correlated the behavioral outcomes to the activity levels of pyramidal neurons in the ACC by analyzing their electrophysiological properties ex vivo. We found that early exposure to an enriched environment alone was not sufficient to cause resilience against pain-induced depression-like symptoms. However, extending the enrichment after the injury prevented the development of depression and reduced mechanical hypersensitivity. On the cellular level, increased neuronal excitability was associated with the depressive phenotype that was reversed by the enrichment. Therefore, neuronal excitability in the ACC was inversely correlated to the extended enrichment-induced resilience to depression. These results suggest that the improvement of environmental factors enhanced the resilience to developing chronic pain-related depression. Additionally, we confirmed the association between increased neuronal excitability in the ACC and depression-like states. Therefore, this non-pharmacological intervention could serve as a potential treatment strategy for comorbid symptoms of chronic pain

Aristonectes quiriquinensis, sp. nov., a new highly derived elasmosaurid from the upper Maastrichtian of central Chile

This paper describes a new species of elasmosaurid plesiosaur, Aristonectes quiriquinensis, sp. nov., based on a partial skeleton recovered from upper Maastrichtian beds of the Quiriquina Formation of central Chile. The material described here consists of two skeletons, one collected near the village of Cocholgue, and a second juvenile specimen from Quiriquina Island. Prior to these finds, Aristonectes was viewed as a monospecific genus, including only the enigmatic Aristonectes parvidens, the holotype of which consists of an incomplete skull and incomplete postcranium. Other material referred to the genus includes an incomplete juvenile skull and other postcranial material from the upper Maastrichtian of Antarctica, as well as a partial skull from the Quiriquina Formation of central Chile. The relationships of Aristonectes have been controversial, with competing theories assigning the genus to Cryptoclididae, Elasmosauridae, and Aristonectidae; however, there is a developing consensus that Aristonectes is a derived elasmosaurid, and this paper gives strong evidence for this view. Comparison of the specimen here studied with the holotype of A. parvidens demonstrates that A. quiriquinensis is a distinct species. The completeness of the adult skeleton allows the first confident size estimates for adult Aristonectes. It is a large plesiosaurian with a relatively large skull with numerous homodont teeth, a moderately long and laterally compressed neck, and relatively narrow trunk, with slender and elongate forelimbs. The two specimens are restricted to the upper Maastrichtian of central Chile, posing questions concerning the austral circumpolar distribution of different elasmosaurids towards the end of the Cretaceous.Fil: Otero, Rodrigo A.. Universidad de Chile; ChileFil: Soto Acuña, Sergio. Museo Nacional de Historia Natural de Santiago; Chile. Universidad de Chile; ChileFil: O'Keefe, Frank Robin. Marshall University; Estados UnidosFil: O'gorman, Jose Patricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; ArgentinaFil: Stinnesbeck, Wolfgang. Heidelberg University; AlemaniaFil: Suárez, Mario E.. Museo Nacional de Historia Natural de Santiago; Chile. Universidad de Chile; ChileFil: Rubilar-Rogers, David. Museo Nacional de Historia Natural de Santiago; Chile. Universidad de Chile; ChileFil: Salazar, Christian. Museo Nacional de Historia Natural de Santiago; Chile. Universidad de Chile; ChileFil: Quinzio Sinn, Luis Arturo. Universidad de Concepción; Chil

Anatomy and histochemistry of leaves, stem and xylopodium of Gomphrena perennis L.

Gomphrena perennis L. es una hierba perenne nativa,distribuida en el norte y centro de Argentina,a la cual se le atribuyen propiedades emolientes,diuréticas, depurativas, estomacales, febrífugas, antirreumáticasy antidiarreicas. Nuestro objetivo fueestudiar la anatomía de hoja, tallo y xilopodio deG. perennis y realizar pruebas histoquímicas paradetectar sustancias ergásticas, para lo cual se recolectaronplantas en las cimas y laderas de Sierra deLos Padres y La Vigilancia, pcia. de Buenos Aires.Se diafanizaron hojas mediante la técnica de clarificación5-5-5, para caracterizar su epidermis. Serealizaron cortes transversales (C.T.) de materialfresco de los órganos y se tiñó con colorantes ortocromáticosy metacromáticos para observar la disposición de los tejidos. Además, se realizaron pruebashistoquímicas para determinar almidón, aceites,taninos y mucílagos. En la hoja, el diafanizadomostró una disposición estomática de tipo anomocítica,y el C.T. una anatomía tipo Kranz y drusasentre los haces vasculares. Además, se observarontricomas epidérmicos no glandulares. En el tallo seobservó colénquima angular subepidérmico, un crecimientosecundario anómalo, drusas, y se evidenciócontenido de almidón. Si bien los análisis histoquímicospreliminares no demostraron la presenciade aceites, mucílagos y taninos, se continuarácon los estudios para identificar posibles principiosactivos presentes en plantas que crecen en las sierrasde Buenos Aires.Fil: Acuña, A. L. A.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; ArgentinaFil: Thevenon, Mario. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; ArgentinaFil: Martinez Tosto, Ana Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones en Sanidad Producción y Ambiente. - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Instituto de Investigaciones en Sanidad Producción y Ambiente; ArgentinaFil: Fernández Honaine, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Cardinali, Francisco José. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones en Sanidad Producción y Ambiente. - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Instituto de Investigaciones en Sanidad Producción y Ambiente; ArgentinaXXXVIII Jornadas Argentinas de BotánicaEntre RíosArgentinaSociedad Argentina de Botánic

Genetic transfer from several apomictic tetraploid Paspalum species to an elite group of sexual plants

Basic findings from classical genetic studies are available for exploiting apomixis in the breeding of several forage grass genera. Most Paspalum species are multiploid with a sexual diploid cytotype and conspecific apomictic polyploid (mainly tetraploid) cytotypes. Experimental tetraploidized diploids reproduce sexually and, when crossed with natural apomictic tetraploids, yield hybrid populations that segregate for reproductive mode. Genetic studies indicated that apomixis is inherited as a monogenic dominant factor. We recombined 50 selected sexual hybrids obtained from crosses between a tetraploidized sexual genotype of P. plicatulum and 9 natural apomictic tetraploid accessions of 6 species of the Plicatula group. A synthetic sexual tetraploid population (SSTP) of 600 individuals from mixed seed of the 50 intercrossed hybrids was space-planted in the field. Based on evaluations of plant vigor, seed set, ergot tolerance, regrowth after flowering, and cold tolerance, 31 plants were selected. Crosses between most selected plants and two testers, which belonged to P. guenoarum, were performed, and the generated progeny was planted into the field following a randomized block design with 3 replications. The progeny test was evaluated for seed fertility, biomass yield, and cold tolerance. This procedure allowed selection of 10 elite plants from the SSTP. These plants should contain genes recombined from six apomictic species, without the genetic determinants for apomixis. They may be polycrossed to generate an improved sexual population, or crossed with other apomictic genotypes to obtain improved apomictic hybrids.Fil: Novo, Patricia Elda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Acuña, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Urbani, Mario Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Galdeano, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Espinoza, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Quarin, Camilo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

MESSENGER observations of Mercury's magnetosphere during northward IMF

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95214/1/grl25367.pd

Aristonectes quiriquinensis, sp. nov., A New Highly Derived Elasmosaurid from the Upper Maastrichtian of Central Chile

This paper describes a new species of elasmosaurid plesiosaur, Aristonectes quiriquinensis, sp. nov., based on a partial skeleton recovered from upper Maastrichtian beds of the Quiriquina Formation of central Chile. The material described here consists of two skeletons, one collected near the village of Cocholgue, and a second juvenile specimen from Quiriquina Island. Prior to these finds, Aristonectes was viewed as a monospecific genus, including only the enigmatic Aristonectes parvidens, the holotype of which consists of an incomplete skull and incomplete postcranium. Other material referred to the genus includes an incomplete juvenile skull and other postcranial material from the upper Maastrichtian of Antarctica, as well as a partial skull from the Quiriquina Formation of central Chile. The relationships of Aristonectes have been controversial, with competing theories assigning the genus to Cryptoclididae, Elasmosauridae, and Aristonectidae; however, there is a developing consensus that Aristonectes is a derived elasmosaurid, and this paper gives strong evidence for this view. Comparison of the specimen here studied with the holotype of A. parvidens demonstrates that A. quiriquinensis is a distinct species. The completeness of the adult skeleton allows the first confident size estimates for adult Aristonectes. It is a large plesiosaurian with a relatively large skull with numerous homodont teeth, a moderately long and laterally compressed neck, and relatively narrow trunk, with slender and elongate forelimbs. The two specimens are restricted to the upper Maastrichtian of central Chile, posing questions concerning the austral circumpolar distribution of different elasmosaurids towards the end of the Cretaceous.Facultad de Ciencias Naturales y Muse