Protecting biodiversity: Riparian buffers directly affect Appalachian headwater salamanders [abstract]

Abstract only availableSalamanders are the most abundant invertebrate predator in the southern Appalachians; they have the highest biomass, and they are an important species for scientific investigators. Their permeable skin and eggs makes them a great indicator species. Salamanders thrive in riparian areas; they need both aquatic and terrestrial habitats for their food and reproduction needs. They thrive in streams and damp leaf litter, thus logged areas can make the chances of desiccation and starvation much higher. Logging often occurs around headwater streams. My study specifically looks at how logging and riparian buffers affect salamanders inhabiting head water streams. The purpose of this research was to measure the density and abundance of adult salamanders in five experimental streams in North Carolina; three streams were logged leaving riparian buffers of 0, 9, and 30 meter riparian buffers, while two streams were studied as controls. To measure salamander abundance removal sampling occurred at night in four different 3 meter plots in each of the treatment streams. Nine total visits were made to each plot to collect all of the salamanders present. I identified, weighed, measured, and preserved all of the specimens from each location. Descriptive and inferential statistics were used during data analysis.Life Sciences Undergraduate Research Opportunity Progra

A genetically encoded tool for reconstituting synthetic modulatory neurotransmission and reconnect neural circuits in vivo

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Hawk, J. D., Wisdom, E. M., Sengupta, T., Kashlan, Z. D., & Colon-Ramos, D. A. A genetically encoded tool for reconstituting synthetic modulatory neurotransmission and reconnect neural circuits in vivo. Nature Communications, 12(1), (2021): 4795, https://doi.org/10.1038/s41467-021-24690-9.Chemogenetic and optogenetic tools have transformed the field of neuroscience by facilitating the examination and manipulation of existing circuits. Yet, the field lacks tools that enable rational rewiring of circuits via the creation or modification of synaptic relationships. Here we report the development of HySyn, a system designed to reconnect neural circuits in vivo by reconstituting synthetic modulatory neurotransmission. We demonstrate that genetically targeted expression of the two HySyn components, a Hydra-derived neuropeptide and its receptor, creates de novo neuromodulatory transmission in a mammalian neuronal tissue culture model and functionally rewires a behavioral circuit in vivo in the nematode Caenorhabditis elegans. HySyn can interface with existing optogenetic, chemogenetic and pharmacological approaches to functionally probe synaptic transmission, dissect neuropeptide signaling, or achieve targeted modulation of specific neural circuits and behaviors.This work was initiated in the Grass Laboratory at the Marine Biological Laboratories (MBL) with funding through a Grass Fellowship awarded to J.D.H. Thanks to Richard Goodman (OHSU) for encouragement during the conceptualization of the fellowship application, and the 2019 Grass Fellows, Mel Coleman (Grass Director), and Christophe Dupré (Associate Director) for advice and support during the summer fellowship. We thank the MBL Division of Education and participants in the Vendor Equipment Loan Program. Special thanks to Sutter Instruments, who generously provided all electrophysiology equipment and substantial on-site assistance, and Zeiss, who provided on-site assistance at MBL. We thank Zhao-Wen Wang and Ping Liu (UConn) for guidance and training in patch-clamp electrophysiology, as well as providing Neuro2a cells. We thank Rob Steele (UCI) for supplying Hydra, as well as advice and inspiration on Hydra biology. We thank members of the Colón-Ramos lab and Hari Shroff (NIH) for thoughtful comments on the manuscript. We thank Michael Koelle and Andrew Olson (Yale University) for advice and reagents regarding serotonin rewiring experiments. We also thank Steve Flavell (MIT) for ideas and reagents regarding the experiments associated with del-7. We thank Life Science Editors for editing assistance. D.A.C.-R. is an MBL Fellow. Research in the D.A.C.-R. lab was supported by NIH R01NS076558, DP1NS111778, and by an HHMI Scholar Award

Protecting biodiversity: Riparian buffers directly affect Appalachian headwater salamanders [abstract]

Abstract only availableThere is growing evidence of worldwide amphibian decline. These declines are largely due to land use such as timber harvest in riparian zones. The southern Appalachian Mountains have miles of streams and arguably the greatest diversity of salamanders in the world. Salamanders are the most abundant predator of invertebrate organisms in the southern Appalachians where their biomass often exceeds that of birds and small mammals. Because salamanders have permeable skin and eggs and are sensitive to changes in the environment, they are good indicators of environmental health. Salamanders thrive in riparian areas where they need both aquatic and terrestrial habitats for foraging and reproduction. My study specifically looks at how logging and riparian buffers affect salamanders inhabiting head water streams. The purpose of my research was to measure the density and abundance of adult salamanders in five experimental streams in North Carolina; three were logged retaining 0, 9, and 30 meter riparian buffers, while two streams were studied as controls. Salamander abundance was estimated through removal sampling at each of the streams. I collected 393 total salamanders and found that salamander densities where the highest in the 0m and 9m sites with Desmognathus monticola being the most abundant. The lowest densities were in the 30m and the two controls sites. My results have implications for the long-term persistence of salamanders in streams following logging in riparian habitats