Striatal cholinergic interneurons generate beta and gamma oscillations in the corticostriatal circuit and produce motor deficits

Cortico-basal ganglia-thalamic (CBT) neural circuits are critical modulators of cognitive and motor function. When compromised, these circuits contribute to neurological and psychiatric disorders, such as Parkinson's disease (PD). In PD, motor deficits correlate with the emergence of exaggerated beta frequency (15-30 Hz) oscillations throughout the CBT network. However, little is known about how specific cell types within individual CBT brain regions support the generation, propagation, and interaction of oscillatory dynamics throughout the CBT circuit or how specific oscillatory dynamics are related to motor function. Here, we investigated the role of striatal cholinergic interneurons (SChIs) in generating beta and gamma oscillations in cortical-striatal circuits and in influencing movement behavior. We found that selective stimulation of SChIs via optogenetics in normal mice robustly and reversibly amplified beta and gamma oscillations that are supported by distinct mechanisms within striatal-cortical circuits. Whereas beta oscillations are supported robustly in the striatum and all layers of primary motor cortex (M1) through a muscarinic-receptor mediated mechanism, gamma oscillations are largely restricted to the striatum and the deeper layers of M1. Finally, SChI activation led to parkinsonian-like motor deficits in otherwise normal mice. These results highlight the important role of striatal cholinergic interneurons in supporting oscillations in the CBT network that are closely related to movement and parkinsonian motor symptoms.DP2 NS082126 - NINDS NIH HHS; R01 NS081716 - NINDS NIH HHS; R21 NS078660 - NINDS NIH HHShttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC4896681/Published versio

Metabarcoding of marine zooplankton: prospects, progress and pitfalls

Metabarcoding (large-scale taxonomic identification of complex samples via analysis of one or few orthologous DNA regions, called barcodes) is revolutionizing analysis of biodiversity of marine zooplankton assemblages. Metabarcoding relies on high-throughput DNA sequencing (HTS) technologies, which yield millions of DNA sequences in parallel and allow large-scale analysis of environmental samples. Metabarcoding studies of marine zooplankton have used various regions of nuclear small- (18S) and large-subunit (28S) rRNA, which allow accurate classification of novel sequences and reliable amplification with consensus primers, but- due to their relatively conserved nature- may underestimate species diversity in a community. To discriminate species, more variable genes are needed. A limited number of metabarcoding studies have used mitochondrial cytochrome oxidase I (COI), which ensures detection of species-level diversity, but may require group-specific primers and thus result in inconsistent amplification success rates. Reference databases with sequences for accurately-identified species are critically needed to allow taxonomic designation of molecular operational taxonomic units (MOTU) and comparison with previous studies of zooplankton diversity. Potential and promising applications of metabarcoding include rapid detection of impacts of climate change, monitoring and assessment of ecosystem health, calculation of biotic indices, characterization of food webs and detection of introduced, non-indigenous species

Bathypelagic Fish Diversity in the Sargasso Sea, Northwestern Atlantic Ocean

Of the various marine habitats, one of the (if not the) most daunting to quantify is the under-sampled bathypelagic zone (\u3e 1000 m depth), which at 60% of the ocean’s volume is the largest habitat on Earth. One project addressing this challenge is the Census of Marine Zooplankton (CMarZ), whose goal is the assessment of biodiversity of animal plankton throughout the world’s oceans. The 2006 CMarZ cruise in the Western North Atlantic provided an unprecedented opportunity to sample bathypelagic micronekton using a large midwater trawl (10-m2 MOCNESS) outfitted with fine (0.335-mm) mesh netting. This netting allowed non-destructive sampling of the fragile fish fauna to 5000 m depth, thus facilitating accurate identification and at-sea DNA extraction and sequencing. A total of 3,965 fish specimens were collected from at least 127 species (84 genera, 42 families), many rarely caught, and four of which may be undescribed. Of note were male anglerfishes from five families, which are poorly known. Tissue was taken from all males to match with females, thus enabling the construction of a key for the most diverse bathypelagic fish group

Habitat usage by the cryptic copepods Pseudocalanus moultoni and P. newmani on Georges Bank (Northwest Atlantic)

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Continental Shelf Research 111 (2015): 83-94, doi:10.1016/j.csr.2015.11.001.The cryptic copepod species, Pseudocalanus moultoni and P. newmani, co-occur on Georges Bank and in the Gulf of Maine (Northwest Atlantic); even recent studies have reported results and conclusions based on examination of the combined species. Species-specific PCR (SS-PCR) based on mitochondrial cytochrome oxidase I (COI) sequence divergence was used in this study to discriminate the species. Species-specific descriptions of habitat usage and predicted patterns of transport and retention on Georges Bank were made by mapping distributions and calculating abundances of each species from January to June, 1999 for four vertical strata (0-15 m, 15-40 m, 40-100 m, and 0-100 m) and five regions (Northern Flank, Bank Crest, Northeast Peak, Southern Flank, and Slope Water) identified on the basis of bathymetry and circulation. Patterns of distribution and abundance for the two species during January to June, 1999 were largely consistent with those described based on vertically integrating mapping and analysis for the same period in 1997 by McGillicuddy and Bucklin (2002). The region-specific and depth-stratified analyses allowed further discrimination in habitat usage by the species and confirmed the distinctive patterns for the two species. The observed differences between the species in abundances among the five regions and three depth strata over Georges Bank impact their transport trajectories. The concentration of P. moultoni in deep layers likely explains the higher rates of retention and lower rates of advective loss of this species from the Bank, compared to P. newmani, which may be more subject to wind-driven transport in the surface layer. Accurate identification and discrimination of even closely-related and cryptic species is needed to ensure full understanding and realistic predictions of changes in diversity of zooplankton and the functioning of pelagic ecosystems.Funding was provided by the National Science Foundation as part of the U.S. GLOBEC Program (Award Nos. OCE-9529100 and OCE-9632840 to Ann Bucklin; Award No. OCE-0815047 to Dennis McGillicuddy)

Consumers don't play dice, influence of social networks and advertisements

Empirical data of supermarket sales show stylised facts that are similar to stock markets, with a broad (truncated) Levy distribution of weekly sales differences in the baseline sales [R.D. Groot, Physica A 353 (2005) 501]. To investigate the cause of this, the influence of social interactions and advertisements are studied in an agent-based model of consumers in a social network. The influence of network topology was varied by using a small-world network, a random network and a Barabasi-Albert network. The degree to which consumers value the opinion of their peers was also varied. On a small-world and random network we find a phase-transition between an open market and a locked-in market that is similar to condensation in liquids. At the critical point, fluctuations become large and buying behaviour is strongly correlated. However, on the small world network the noise distribution at the critical point is Gaussian, and critical slowing down occurs which is not observed in supermarket sales. On a scale-free network, the model shows a transition between a gas-like phase and a glassy state, but at the transition point the noise amplitude is much larger than what is seen in supermarket sales. To explore the role of advertisements, a model is studied where imprints are placed on the minds of consumers that ripen when a decision for a product is made. The correct distribution of weekly sales returns follows naturally from this model, as well as the noise amplitude, the correlation time and cross-correlation of sales fluctuations. For particular parameter values, simulated sales correlation shows power law decay in time. The model predicts that social interaction helps to prevent aversion, and that products are viewed more positively when their consumption rate is higher.Comment: Accepted for publication in Physica

Low Pressure Greenhouse Concepts for Mars

A project was initiated to begin testing some environmental limits for managing plant growth systems. These limits will help determine some of the concepts for building plant enclosures for use on Mars. In particular, this study focuses on the effects of reduced atmospheric pressures. Structural design is considered as it relates to the biological processes that would occur within that structure. The design must be closely tied to the functionality of the biological system and has a few primary concerns that need to be tested to resolve the question as to the path of the design. Early tests indicate that plants can survive and grow at low (greater than 76 mb) pressure

Preliminary Estimates of the Possibilities for Developing a Deployable Greenhouse for a Planetary Surface (Mars)

Two of the main conditions for plant growth and development on the Martian surface are irradiation (optimal range from 80 W/sq m to 180 W/sq m of photosynthetically active radiation) and temperature (optimal range from 20 C to 27 C). The only known natural source of energy on Mars is sunlight, with a general intensity of 589 +/- 142 W/sq m (Martian Solar Constant). Comparisons of plant growth requirements with conditions on the Martian surface are presented in Table 1, while some basic considerations for implementing plant growth in a Martian DG are presented in Table 2. The general scenario and approximate schedule of startup and development of operations in DG are shown in Table 3