Formation of a morphine-conditioned place preference does not change the size of evoked potentials in the ventral hippocampus–nucleus accumbens projection

Abstract In opioid addiction, cues and contexts associated with drug reward can be powerful triggers for drug craving and relapse. The synapses linking ventral hippocampal outputs to medium spiny neurons of the accumbens may be key sites for the formation and storage of associations between place or context and reward, both drug-related and natural. To assess this, we implanted rats with electrodes in the accumbens shell to record synaptic potentials evoked by electrical stimulation of the ventral hippocampus, as well as continuous local-field-potential activity. Rats then underwent morphine-induced (10 mg/kg) conditioned-place-preference training, followed by extinction. Morphine caused an acute increase in the slope and amplitude of accumbens evoked responses, but no long-term changes were evident after conditioning or extinction of the place preference, suggesting that the formation of this type of memory does not lead to a net change in synaptic strength in the ventral hippocampal output to the accumbens. However, analysis of the local field potential revealed a marked sensitization of theta- and high-gamma-frequency activity with repeated morphine administration. This phenomenon may be linked to the behavioral changes—such as psychomotor sensitization and the development of drug craving—that are associated with chronic use of addictive drugs

Role of Biochar in Carbon Sequestration and Greenhouse Gas Mitigation

Not AvailableGlobal warming and associated climate change are becoming a threat to almost all the ecosystems on the earth. According to the intergovernmental panel on climate change (IPCC) special report 2019, the global mean surface (land and ocean) temperature has been increased by 0.87 °C while mean of land surface air temperature has increased by 1.53 °C since 1850–2015. Climate change is affecting food security and human life due to warming, changing precipitation patterns, and the greater frequency of some extreme events. The main cause of global warming is the continuous increase in the atmospheric concentration of greenhouse gases (GHGs) like CO2, CH4, N2O and fluorinated gases due to several anthropogenic activities. Therefore, reducing the increasing concentration of GHG is necessary to slow down global warming and climate change. Among several options of greenhouse mitigation, application of biochar into the soil is gaining popularity due to several advantages over other options. Biochar is a highly stable form of carbon derived from pyrolysis of biomass at relatively low temperatures. Application of biochar into the soil has been reported to provide multiple benefits like increase in crop yield, nutrient and water use efficiency and several environmental benefits. Recalcitrant nature, relatively higher carbon content and easily available feedstock make biochar a highly sustainable and quick option for carbon sequestration into the soil. Biochar application into the soil not only helps in carbon sequestration but also provides a better option for managing agricultural residues. The application of biochar has also reported for reducing a considerable amount of methane and nitrous oxide emission from the agricultural field due to its priming effect on the soil. Biochar yield, physical properties, and carbon content varies with the type of feedstock and pyrolysis condition. Therefore, the rate of carbon sequestration and mitigation of greenhouse gas is also highly variable, however, the biochar application ultimately leads to a positive contribution towards climate change mitigation. However, most of the reported benefits are confined to laboratory and field trial at institute level, widespread adoption of biochar on farmer’s field is still lacking. In the present chapter, all the aspects of biochar towards carbon sequestration and greenhouse mitigation have been well discussed.Not Availabl