Default mode network modulation by psychedelics : a systematic review

Psychedelics are a unique class of drug that commonly produce vivid hallucinations as well as profound psychological and mystical experiences. A grouping of interconnected brain regions characterized by increased temporal coherence at rest have been termed the Default Mode Network (DMN). The DMN has been the focus of numerous studies assessing its role in self-referencing, mind wandering, and autobiographical memories. Altered connectivity in the DMN has been associated with a range of neuropsychiatric conditions such as depression, anxiety, post-traumatic stress disorder, attention deficit hyperactive disorder, schizophrenia, and obsessive-compulsive disorder. To date, several studies have investigated how psychedelics modulate this network, but no comprehensive review, to our knowledge, has critically evaluated how major classical psychedelic agents-lysergic acid diethylamide, psilocybin, and ayahuasca-modulate the DMN. Here we present a systematic review of the knowledge base. Across psychedelics there is consistent acute disruption in resting state connectivity within the DMN and increased functional connectivity between canonical resting-state networks. Various models have been proposed to explain the cognitive mechanisms of psychedelics, and in one model DMN modulation is a central axiom. Although the DMN is consistently implicated in psychedelic studies, it is unclear how central the DMN is to the therapeutic potential of classical psychedelic agents. This article aims to provide the field with a comprehensive overview that can propel future research in such a way as to elucidate the neurocognitive mechanisms of psychedelics

EPOCA/EUR-OCEANS data compilation on the effects of ocean acidification, 2011

The uptake of anthropogenic CO2 by the oceans has led to a rise in the oceanic partial pressure of CO2, and to a decrease in pH and carbonate ion concentration. This modification of the marine carbonate system is referred to as ocean acidification. Numerous papers report the effects of ocean acidification on marine organisms and communities but few have provided details concerning full carbonate chemistry and complementary observations. Additionally, carbonate system variables are often reported in different units, calculated using different sets of dissociation constants and on different pH scales. Hence the direct comparison of experimental results has been problematic and often misleading. The need was identified to (1) gather data on carbonate chemistry, biological and biogeochemical properties, and other ancillary data from published experimental data, (2) transform the information into common framework, and (3) make data freely available. The present paper is the outcome of an effort to integrate ocean carbonate chemistry data from the literature which has been supported by the European Network of Excellence for Ocean Ecosystems Analysis (EUR-OCEANS) and the European Project on Ocean Acidification (EPOCA). A total of 185 papers were identified, 100 contained enough information to readily compute carbonate chemistry variables, and 81 data sets were archived at PANGAEA - The Publishing Network for Geoscientific & Environmental Data. This data compilation is regularly updated as an ongoing mission of EPOCA

An Updated Synthesis of the Impacts of Ocean Acidification on Marine Biodiversity (CBD Technical Series ; 75)

From the foreword: This report, CBD Technical Series No. 75, “An updated synthesis of the impacts of ocean acidification on marine biodiversity”, represents an enormous scientific effort by researchers and experts from around the world to synthe- size the best available and most up-to-date information on the impacts of changing ocean pH on the health of the world’s oceans. Among other findings, the report notes that ocean acidifica- tion has increased by around 26% since pre-industrial times and that, based on historical evidence, recovery from such changes in ocean pH can take many thousands of years. The report outlines how ocean acidification impacts the physi- ology, sensory systems and behavior of marine organisms, and undermines ecosystem health. It, furthermore, shows that impacts due to ocean acidification are already under- way in some areas and that future projected impacts could have drastic irreversible impacts on marine ecosystems. Despite the growing body of information on ocean acidifica- tion, the report points out key knowledge gaps and, in light of the many complex interactions related to ocean chemis- try, stresses the difficulty of assessing how future changes to ocean pH will affect marine ecosystems, food webs and ecosystems, and the goods and services they provide. This report, which presents complex scientific information on ocean acidification in a clear and understandable way, provides an important reference point for scientists, policy- makers and anyone else interested in understanding how ocean acidification affects our oceans and the vital services they provide. As the need for urgent action to address ocean acidification becomes ever more pressing, collaboration among governments and organizations in enhancing and sharing knowledge through efforts such as this report will become increasingly important

Changes in surface CO2 and ocean PH in ICES shelf sea ecosystems

36 pages, 3 annex, 21 figuresThe primary purpose of this document is to report the recommendations resulting from the ICES WORKSHOP ON THE SIGNIFICANCE OF CHANGING OCEAN CO2 AND PH IN ICES SHELF SEA ECOSYSTEMS held between 2 and 4 May 2007 in London. Some excel‐ lent reports have already been published in this field, first by the Scientific Commit‐ tee on Oceanic Research (SCOR; Arvidson, 2005), then by the National Oceanic and Atmospheric Administration/National Science Foundation/US Geological Survey (NOAA/NSF/USGS; Kleypas et al., 2006), the Royal Society (The Royal Society, 2005), the German Advisory Council on Global Change (WBGU; WBGU, 2006), and most recently by the OSPAR Commission (OSPAR, 2006) and the Intergovernmental Panel on Climate Change (IPCC; Metz et al., 2005). Cognizant of these recent efforts, the ICES Workshop set out with a slightly different aim to investigate the links between potential changes in pH and its effects on marine ecosystem components, such as plankton, fish and shellfish, and cold‐water corals. To this end, the Workshop covered ground already considered by others, to provide a sound base for the prediction of likely impacts. The present report will outline those relevant issues, but the reader is advised to refer to other reports for greater detail. The novel focus of this report is the potential effects on ecosystem functions with links to fisheries, with a recommendation for work to be done to better understand the impact of this problem on the entire ecosystem, and specifically on fisheries. Most of the material used was presented at the Workshop, with Annex 1 being the most significant exceptionPeer reviewe

Comment on "Modern-age buildup of CO2 and its effects on seawater acidity and salinity" by Hugo A. Loaiciga

A doubling of present atmospheric CO2 concentrations (to 760 ppm) may occur by the end of this century in the absence of efforts to diminish CO2 emissions from fossil-fuel combustion [Intergovernmental Panel on Climate Change (IPCC), 2001]. Based on inappropriate assumptions and erroneous thermodynamic calculations, Loa´ iciga [2006] mistakenly reports that atmospheric CO2 concentrations of 760 ppm will lower the pH of the surface ocean by 0.28 relative to the natural ‘‘mid 18th century’’ conditions. He implies that a drop of this magnitude will have minimal biological impact, neglecting numerous recent experiments and observations showing that this decrease in pH would substantially affect the physiology and health of marine organisms. Here, we focus on two fundamental flaws in the published analysis that invalidate his conclusions: (1) he assumes instantaneous chemical equilibration of the ocean with carbonate minerals although this process is known to take five to ten thousand years and (2) contrary to what is implied by Loa´iciga, many marine organisms are sensitive to a pH decrease of 0.2 units