Thalamic inputs to dorsomedial striatum are involved in inhibitory control: evidence from the five-choice serial reaction time task in rats

Rationale Corticostriatal circuits are widely implicated in the top-down control of attention including inhibitory control and behavioural flexibility. However, recent neurophysiological evidence also suggests a role for thalamic inputs to striatum in behaviours related to salient, reward-paired cues. Objectives Here, we used designer receptors exclusively activated by designer drugs (DREADDs) to investigate the role of parafascicular (Pf) thalamic inputs to the dorsomedial striatum (DMS) using the five-choice serial reaction time task (5CSRTT) in rats. Methods The 5CSRTT requires sustained attention in order to detect spatially and temporally distributed visual cues and provides measures of inhibitory control related to impulsivity (premature responses) and compulsivity (perseverative responses). Rats underwent bilateral Pf injections of the DREADD vector, AAV2-CaMKIIa-HA-hM4D(Gi)-IRES-mCitrine. The DREADD agonist, clozapine N-oxide (CNO; 1 μl bilateral; 3 μM) or vehicle, was injected into DMS 1 h before behavioural testing. Task parameters were manipulated to increase attention load or reduce stimulus predictability respectively. Results We found that inhibition of the Pf-DMS projection significantly increased perseverative responses when stimulus predictability was reduced but had no effect on premature responses or response accuracy, even under increased attentional load. Control experiments showed no effects on locomotor activity in an open field. Conclusions These results complement previous lesion work in which the DMS and orbitofrontal cortex were similarly implicated in perseverative responses and suggest a specific role for thalamostriatal inputs in inhibitory control

Rabies screen reveals GPe control of cocaine-triggered plasticity.

Identification of neural circuit changes that contribute to behavioural plasticity has routinely been conducted on candidate circuits that were preselected on the basis of previous results. Here we present an unbiased method for identifying experience-triggered circuit-level changes in neuronal ensembles in mice. Using rabies virus monosynaptic tracing, we mapped cocaine-induced global changes in inputs onto neurons in the ventral tegmental area. Cocaine increased rabies-labelled inputs from the globus pallidus externus (GPe), a basal ganglia nucleus not previously known to participate in behavioural plasticity triggered by drugs of abuse. We demonstrated that cocaine increased GPe neuron activity, which accounted for the increase in GPe labelling. Inhibition of GPe activity revealed that it contributes to two forms of cocaine-triggered behavioural plasticity, at least in part by disinhibiting dopamine neurons in the ventral tegmental area. These results suggest that rabies-based unbiased screening of changes in input populations can identify previously unappreciated circuit elements that critically support behavioural adaptations

Can the Adaptive Multi-Paddock Grazing System Increase Carbon Sequestration in Alberta's Grassland Soils?

Natural grasslands cover around 40% of the Earth’s surface and play an important role as a source of ecological goods and services. By sequestering around 30% of terrestrial global carbon, grasslands play a critical part in the alleviation of climate change. Despite their ecological significance, grasslands have been reduced to a fraction of their original extent. In Canada, up to 70% of grasslands have been destroyed, making it the most endangered ecosystem in North America. What remains is often intensely grazed and a diverse ecosystem of wild animals is replaced by domestic livestock. The continuous application of poor grazing management by ranchers is one of the main causes for the depletion of natural grasslands, resulting in the release of stored soil carbon back into the atmosphere. Fortunately, 60-70% of the depleted carbon can be re-sequestered through the adoption of improved grazing management, thus improving grassland ecosystems. The Adaptive Multi-Paddock (AMP) grazing system is an example of improved grazing management. AMP grazing is a system in which livestock is frequently rotated between multiple fenced paddocks. Compared to conventional grazing practices (Non-AMP), the AMP system is a favorable solution which can improve carbon sequestration in world wide grasslands soils– and in turn, contribute to the mitigation of climate change. By regenerating grassland ecosystems, AMP grazing could potentially aid in creating a more sustainable, resilient agroecosystem. Our goal is to study the effect of AMP grazing on soil organic carbon (SOC) sequestration in Canadian grasslands. First, we collected soil cores from 30 study sites located throughout the grassland ecoregions in Canada. Each site consisted of a pair of ranches: one AMP and one Non-AMP. Second, we analyzed the soil cores for total carbon using an elemental analyzer. There does not seem to be any substantial difference in total carbon between AMP and Non-AMP systems, however we have yet to differentiate between soil organic carbon and soil inorganic carbon. Once we distinguish the two variables we will be able to confirm the effectiveness of the AMP grazing system in increasing carbon sequestration in Canadian grasslands. Literature Cited: Derner, J. D., & Schuman, G. E. (2007). Carbon sequestration and rangelands: a synthesis of land management and precipitation effects. Journal of soil and water conservation, 62(2), 77-85. Gauthier, D. A., & Wiken, E. B. (2003). Monitoring the conservation of grassland habitats, Prairie Ecozone, Canada. Environmental Monitoring and Assessment, 88(1-3), 343-364. Samson, F., & Knopf, F. (1994). Roundtable: prairie conservation in North America. BioScience, 44(6), 418-421 Kraus, D. (2016). Why Canada’s Prairies are the World’s Most Endangered Ecosystem. Retrieved from: http://www.natureconservancy.ca/en/blog/archive/grasslands-the-most.html#.XUnsE-hKi70 Lal, R. (2002). Soil carbon dynamics in cropland and rangeland. Environmental pollution, 116(3), 353-362 Teague, W. R. (2018). Forages and pastures symposium: Cover crops in livestock production: Whole-system approach: Managing grazing to restore soil health and farm livelihoods. Journal of animal science, 96(4), 1519-1530

Changes in Alberta’s Grasslands Soil pH by Adopting the Adaptive Multi-Paddock Grazing System

Grasslands account for a large percentage of earth’s terrestrial area. Soil is an important aspect of the global carbon cycle and plays a critical role in mitigating climate change. Due to poor land management, the grasslands have been greatly degraded, resulting in the grasslands becoming the most endangered ecosystem on the planet. Fortunately, there are several new techniques that can be implemented in order to help alleviate the negative impacts that the depleted grasslands have had on the earth. The Adaptive-Multi Paddock (AMP) grazing system is an innovative technique that has been introduced as a way to increase plant regrowth, improve animal performance, and increase soil organic carbon (SOC) levels. As SOC has been shown to be correlated to soil pH, there is potential for the AMP system to affect soil pH. To implement the AMP system, a rancher’s land would be divided into multiple small paddocks, and the cattle would be rotated between the paddocks more frequently. Non-AMP managed ranches include any ranch that uses traditional grazing techniques, such as low or high continuous grazing. The purpose of this project was to study the effects of the AMP grazing system on the pH of Alberta’s grassland soil. Soil samples were collected from AMP and Non-AMP managed ranches in Alberta. After the samples were separated into several layers, weighed, dried, and sieved, the pH of each soil section was recorded and analyzed. Using the data from the Albertan ranches, the AMP and Non-AMP managed ranches were compared. From this data, it appears that by using the AMP system, the pH was slightly lower across all soil depths. Soil also appeared to become more basic with each successive layer. Between Alberta’s four ecoregions, the average soil pH seemed to vary. In both AMP and Non-AMP managed ranches, the subsoil was more alkaline while the topsoil was more acidic, which could be a result of possible higher SOC concentrations. In future studies, the pH data from Alberta’s soils will be compared to the Saskatchewan and Manitoba data, which will represent all of Canada’s grassland soil. When the SOC data is collected, the pH and SOC concentration will be analyzed to establish a correlation. Ultimately, farmers might be reimbursed for the additional costs of adopting the AMP system because of the environmental benefits the system could have

Defining Success for Students with Autism Spectrum Disorder: Social Academic Behavior in General Education Secondary Classes

An exploratory, observation-based study sought to strengthen understanding of the development of social communication skills that facilitate academic success, particularly within general education settings. Sixteen middle and high school students with Autism Spectrum Disorders (ASD), all of whom participated in at least one period per day of core academic instruction in a general education classroom, were observed over a period of one to three months each. Frequencies of five appropriate and three inappropriate social academic behaviors are described, in terms of their relative frequencies to one another, and their overall consistency over the course of observations. Students observed were more likely to engage in appropriate, facilitative behaviors within the classroom setting than they were to demonstrate communicative symptoms of ASD. Most social academic behaviors were demonstrated at consistent frequencies over time. Implications for educational decision-making, progress monitoring, and future research are discussed

Proglacial sediments in High Arctic glacier foreland: A case study of Werenskioldbreen, Svalbard

The glacier environment exhibits a high sensitivity to global climate change, leading to progressive deglaciation and the exposure of previously ice-covered land. The newly exposed terrain provides a valuable opportunity to observe rapid ecosystem changes, such as the accumulation of glacial sediments, the development of soil-forming and progressive alterations in water and biogeochemical cycles. While developing hydrological and hydrogeological models for the Werenskioldbreen proglacial expanding zone, we encountered a significant problem due to insufficient data for parameterizing glacial sediments, which constitute the environment for water flow and storage. This study provides detailed insight into the physicochemical parameters of glacial sediments and classifies them in terms of grain size distribution, hydraulic conductivity, pH and the content of carbon (Corg), nitrogen (Nt) and phosphorus (Pt). We found that the marginal outwash plains of Werenskioldbreen are characterised by gravelly sand, sandy gravel and silty sand (28.6%, 23.8% and 19% of the total sample contents, respectively). The lateral moraine contains sandy clayey silt, silty sandy gravel or sandy gravelly silt (7.1%, 4.8% and 2.4 % of the total sample contents, respectively). The chemical parameters of young glaciofluvial sediments have lower values than those of moraines. Corg ranged from 0.07% to 2.70%. Nt was < 1.00 g kg−1 for 95% of the samples and < 0.5 g kg−1 for 81% of them. Pt was between 0.48 and 1.18 g kg−1. In line with the studies on this subject already published, we confirm that there is clear a relationship between the type of geomorphological form, its age, and the physicochemical parameters of glacial sediments

Distinct hypothalamus-habenula circuits govern risk preference

Appropriate evaluation of risk is essential for survival in complex, uncertain environments. Confronted with choosing between a certain (safe) and an uncertain (risky) option, animals of various species show strong preferential traits which are stable across extended periods of time$^{1-8}$. How such risk preference is encoded in the neural circuitry of the brain remains poorly understood. A candidate brain region is the lateral habenula (LHb), which has been shown to be prominently involved in various value-guided behaviors$^{9-12}$. Here, using a balanced two-alternative choice task involving risk of loss, we find that neuronal activity in the LHb prior to action selection reflects risk preference and is governed by distinct inputs from hypothalamic subregions. Specifically, by employing multi-fiber photometry and targeted optogenetic perturbations, we identified glutamatergic LHb projections from both lateral and medial hypothalamus (LH/MH) that provide functionally distinct synaptic inputs to the LHb before action selection. Microendoscopic two-photon calcium imaging revealed risk-preference-selective LHb neurons that decreased their selectivity upon chemogenetic silencing of MH but not LH inputs. Finally, optogenetic stimulation of MH→LHb axons evoked both excitatory and inhibitory postsynaptic responses in LHb neurons (indicative of glutamate/GABA co-release for fine-tuned gain control$^{13}$), whereas LH→LHb projections were purely excitatory. Our results thus reveal functionally distinct hypothalamus-habenula circuits that govern risk preference in situations of economic decision-making

BOTÂNICA em PRÁTICA: ATIVIDADES PRÁTICAS E EXPERIMENTOS PARA O ENSINO FUNDAMENTAL

O presente artigo tem por finalidade apresentar parte dos resultados obtidos ao longo do desenvolvimento do projeto “Botânica a ciência do dia a dia: atividades práticas como mecanismo de formação e aprendizagem em Ciências e Biologia” financiado pelo programa Universidade sem Fronteiras da Secretaria de Ciência, Tecnologia e Ensino Superior do Estado do Paraná. Para tanto, são apresentados 21 planos de aula, todos relacionados com a área de Botânica, desenvolvidos junto aos alunos de Ensino Fundamental dos colégios estaduais Neusa Domit e Judith Simas Canellas, pertencentes ao Núcleo Regional de Educação de União da Vitória, Paraná. Todos estes planos de aula foram desenvolvidos junto com os alunos de 5º a 9º ano do Ensino Fundamental de ambas os estabelecimentos de ensino. Cada um deles conta com uma descrição básica (Fundamentação teórica), os materiais utilizados e os procedimentos, além de questões discutidas ao longo do desenvolvimento das atividades práticas. Estes planos de aula aqui reunidos têm por finalidade demonstrar que atividades práticas e experimentos simples podem ser facilmente desenvolvidos junto aos alunos do ensino básico, propiciando aos mesmos maior compreensão sobre temas diversos da área de Biologia Vegetal e facilitando a compreensão dos assuntos tratados em sala de aula