Biology subjects

Moore, C. M.

Publications and source records attributed to Moore, C. M..

3 recordsLinked to original sources

bioRxiv2018

Resting-state functional connectivity, cortical GABA and neuroactive steroids in peripartum and peripartum depressed women: a functional magnetic imaging and resonance study

Postpartum depression (PPD) is associated with abnormalities in resting-state functional connectivity (RSFC) but the underlying neurochemistry is unclear. We hypothesized that peripartum GABAergic neuroactive steroids (NAS) are related to cortical GABA concentrations and RSFC in PPD as compared to healthy comparison women (HCW). To test this, we measured RSFC with fMRI and GABA+/Creatine (Cr) concentrations with proton magnetic resonance spectroscopy (1H MRS) in the pregenual anterior cingulate (pgACC) and occipital cortices (OCC) and quantified peripartum plasma NAS. We examined between-group differences in RSFC and the relationship between cortical GABA+/Cr concentrations with RSFC. We investigated the relationship between NAS, RSFC and cortical GABA+/Cr concentrations. Within the default mode network (DMN) an area of the dorsomedial prefrontal cortex (DMPFC) had greater connectivity with the rest of the DMN in PPD (peak voxel: MNI coordinates (2, 58, 32), p=0.002) and was correlated to depression scores (peak HAM-D17 voxel: MNI coordinates (0, 60, 34), p=0.008). pgACC GABA+/Cr correlated positively with DMPFC RSFC in a region spanning the right anterior/posterior insula and right temporal pole (r=+0.661, p=0.000). OCC GABA+/Cr correlated positively with regions spanning both amygdalae (right amygdala: r=+0.522, p=0.000; left amygdala: r=+0.651, p=0.000) as well as superior parietal areas. Plasma allopregnanolone was higher in PPD (p=0.03) and positively correlated with intra DMPFC connectivity (r=+0.548, p=0.000) but not GABA+/Cr. These results provide initial evidence that PPD is associated with altered DMN connectivity; cortical GABA+/Cr concentrations are associated with postpartum RSFC and allopregnanolone is associated with postpartum intra-DMPFC connectivity.

neuroscience↗

bioRxiv2017

The mismatch in distributions of vertebrates and the plants that they disperse

Little is known about how mutualistic interactions affect the distribution of species richness on broad geographic scales. It has been predicted that the richness of species involved in obligate mutualisms should be positively associated across their range. Whereas, if mutualisms are facilitative, the distribution of mutualists should be correlated with other factors. This study is the first study to compare the co-distribution of mutualist species in general and seed dispersal mutualisms specifically. We used geographic distributions of plant and animal mutualists to investigate the co-distribution and patterns of seed dispersal mutualisms. We found the mutualism between dispersers and plants does not account for the distribution of either group. In fact, there is a mismatch of richness between plants and the animals that disperse their seeds. Environmental factors are better predictors of both animal distribution and seed dispersal mutualisms across North America.\n\nStatement of authorshipJD, CM, and SV conceived the original project idea. Plant data were compiled and analyzed by CM and SV, and JD compiled animal and environmental data. JD standardized and formatted all geographical data, and JD and CM performed all statistical analyses. JD wrote the first draft of the manuscript, and all authors contributed significantly to the revisions.

ecology↗

bioRxiv2017

Population dynamics of mutualism and intraspecific density dependence:how θ-logistic-like density dependence affects mutualistic positive feedback

Mutualism describes the biological phenomenon where two or more species are reciprocally beneficial, regardless of their ecological intimacy or evolutionary history. Classic theory shows that mutualistic benefit must be relatively weak, or else it overpowers the stabilizing influence of intraspecific competition and leads to unrealistic, unbounded population growth. Interestingly, the conclusion that strong positive interactions lead to runaway population growth is strongly grounded in the behavior of a single model. This model [-] the Lotka-Volterra competition model with a sign change to generate mutualism rather than competition between species [-] assumes logistic growth of each species plus a linear interaction term to represent the mutualism. While it is commonly held that the linear interaction term is to blame for the models unrealistic behavior, we show here that a linear mutualism added to a{theta} -logistic model of population growth can prevent unbounded growth. We find that when density dependence is decelerating, the benefit of mutualism at equilibrium is greater than when density dependence is accelerating. Although there is a greater benefit, however, decelerating density dependence tends to destabilize populations whereas accelerating density dependence is always stable. We interpret these findings tentatively, but with promise for the understanding of the population ecology of mutualism by generating several predictions relating growth rates of mutualist populations and the strength of mutualistic interaction.

ecology↗