Effect of organic and conventional farming on soil bacterial diversity of pecan tree (Carya illinoensis K. Kosh) orchard across two phenological stages.

We described the bacterial diversity of walnut grove soils under organic and conventional farming. The bacterial communities of rhizospheric and nonrhizospheric soils of pecan tree (Carya illinoensis K. Koch) were compared considering two phenological stages (sprouting and ripening). Sixteen operational taxonomic units (OTUs) were identified significantly more abundant according to the plant development, only one according to the farming condition, and none according to the soil origin. The OTUs specificaly abundant according to plant development included Actinobateria (2) and Betaproteobacteria (1) related OTUs more abundant at the sprouting stage, while at the fruit ripening (FR) stage the more abundant OTUs were related to Actinobacteria (6), Alphaproteobacteria (6), and unclassified Bacteria (1). The Gaiellaceae OTU18 (Actinobacteria) was more abundant under conventional farming. Thus, our study revealed that the plant development stage was the main factor shaping the bacterial community structure, while less influence was noticed for the farming condition. The bacterial communities exhibited specific metabolic capacities, a large range of carbon sources being used at the FR stage. The identified OTUs specifically more abundant represent indicators providing useful information on soil condition, potential tools for the management of soil bacterial communities.

Aggressive behavior during social interaction in mice is controlled by the modulation of tyrosine hydroxylase expression in the prefrontal cortex.

The Balb/c strain and the C57BL/6 strain show constitutive differences for tyrosine hydroxylase expression, and noradrenaline (NA) prefrontal transmission. Male mice of these strains also show striking differences in social interaction behaviors, with an increased aggressiveness for the Balb/c strain. To test a potential link between these neurobiological and behavioral parameters, we evaluated the behavioral effects of chronic treatment of mice with BC19, a noreburnamine compound previously known as RU24722, found to modify cell organisation, tyrosine hydoxylase (TH) expression, and its activity into the locus coeruleus (LC). We compared the pharmacological effects between the two strains in social behaviors. Our results show that the emergence of additional TH-expressing (TH+) neurons in the rostral part of the LC of Balb/c mice was associated with an increase in the density of TH+ and noradrenergic (NA+) fibers in the molecular layer in the cingular (Cg1) and prelimbic (PrL) parts of the prefrontal cortex (PFC). BC19 treatment resulted in the near-equalization of the LC number of TH+ neurons and of the density of TH+ and NA+ fibers between both strains. The aggressiveness in Balb/c mice was considerably diminished by BC19 treatment, while the originally non aggressive behavior of C57Bl/6 mice was much less affected by BC19 treatment, despite a moderate increase in some offensive behaviors. In additional control experiments, we checked the effect of BC19 on a separate test for anxiety and assessed the effect of noradrenergic N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride (DSP-4) mediated lesions in C57BL/6 mice on social behaviors. In the present study we show that the BC19 effect in Balb/c mice was independent of anxiety as measured in the light/dark test and that DSP-4 lesions in C57BL/6 mice produced a robust increase in aggressive social interaction. Altogether, these results show that the noradrenergic system, and particularly its projections to the PFC, strongly modulates aggressive behaviors.

Intoxicación por GHB: A propósito de dos casos / Intoxication by gamma-hydroxibutiric acid: two cases

Se presentan dos casos de intoxicación por GHB o 'éxtasis líquido'. La frecuencia de esta intoxicación ha aumentado mucho en nuestro medio. Los clínicos deberían conocer su existencia y sus efectos adversos (AU)