Digital Commons Network^™

Characterizing First-Year Biology Majors’ Motivations And Perceptions Of The Discipline, Jeremy L. Hsu, Lauren Dudley

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding why students choose to major in biology provides important insight into the motivations of biology majors. It is similarly important to investigate how biology majors perceive the discipline, including associated activities, such as independent research, which can influence students’ interests in the field and likelihood to persist in science, engineering, technology, and math. However, there has been little work done examining biology student motivations and perceptions, particularly at non-research-intensive universities or after the COVID-19 pandemic started. To address this gap, we surveyed the first-year cohort of biology majors at a private, comprehensive university. We found that students largely reported …

Transmembrane Helices Mediate The Formation Of A Stable Ternary Complex Of B5r, Cyt B5, And Scd1, Jiemin Shen, Gang Wu, Ah-Lim Tsai, Ming Zhou

Faculty, Staff and Students Publications

Mammalian cytochrome b5 (cyt b5) and cytochrome b5 reductase (b5R) are electron carrier proteins for membrane-embedded oxidoreductases. Both b5R and cyt b5 have a cytosolic domain and a single transmembrane (TM) helix. The cytosolic domains of b5R and cyt b5 contain cofactors required for electron transfer, but it is not clear if the TM helix has function beyond being an anchor to the membrane. Here we show that b5R and cyt b5 form a stable binary complex, and so do cyt b5 and stearoyl-CoA desaturase-1 (SCD1). We also show that b5R, cyt b5 and SCD1 form a stable ternary complex. …

The Pioneer Advantage: Filling The Blank Spots On The Map Of Genome Diversity In Europe, Taras K. Oleksyk, Walter Wolfsberger, Khrystyna Schubelka, Serghei Mangul, Stephen James O'Brien

Biology Faculty Articles

Documenting genome diversity is important for the local biomedical communities and instrumental in developing precision and personalized medicine. Currently, tens of thousands of whole-genome sequences from Europe are publicly available, but most of these represent populations of developed countries of Europe. The uneven distribution of the available data is further impaired by the lack of data sharing. Recent whole-genome studies in Eastern Europe, one in Ukraine and one in Russia, demonstrated that local genome diversity and population structure from Eastern Europe historically had not been fully represented. An unexpected wealth of genomic variation uncovered in these studies was not so …

Drosophila Melanogaster As A Model For Male Reproductive System Ethanol Toxicity, Gbemisola Ilelaboye

Seton Hall University Dissertations and Theses (ETDs)

Drosophila melanogaster has been extensively used in different types of research as a model organism due to its high reproductivity, short life span, and easy maintenance. In this paper, we examined drosophila as a model for ethanol toxicity in the male reproductive system. We developed three assays: The DAPI assay, sperm viability assay, and tubulin staining assay. The DAPI assay is a nuclear staining assay that assesses the effects of various ethanol concentrations in late spermiogenesis in which increased detrimental effects to the sperm bundles were observed. The second assay consisted of the sperm viability assay which showed an increase …

Recovery Of Soil Microbial Diversity And Functions Along A Tropical Montane Forest Disturbance Gradient, Renee Sniegocki, Jessica B. Moon, Abigail L. Rutrough, Jude Gireneus, Jaya Seelan Sathiya Seelan, Michael C. Farmer, David C. Weindorf, Kusum Naithani

Biological Sciences Faculty Publications and Presentations

Logging and forest conversion are occurring at alarming rates in tropical forests. These disturbances alter soil microbial community structure and functions. While direct links between changes in soil properties, such as pH and microbial community structure are well established, the indirect effects of logging and forest conversion on soil microbial community structure and functions are poorly understood. We used a space-for-time substitution to investigate the changes in soil microbial diversity and functions across a forest recovery gradient in the tropical montane forests of northern Borneo. We used surface (top 5 cm) soil to assess soil physicochemical and microbial (next-generation DNA …

Caloric Restriction Prevents Obesity- And Intermittent Hypoxia-Induced Cardiac Remodeling In Leptin-Deficient Ob/Ob Mice, Aaron A. Jones, Sarah N. Framnes-Deboer, Arianne Shipp, Deanna M. Arble

Biological Sciences Faculty Research and Publications

Background:

Intermittent hypoxia (IH), a key characteristic of obstructive sleep apnea, is independently associated with cardiometabolic impairment. While endogenous leptin levels may provide cardioprotective effects against hypoxia, leptin resistance is common among obese individuals presenting with obstructive sleep apnea.

Methods:

Here, we assessed left ventricle (LV) function using M-mode echocardiography in lean wild-type, calorically-restricted ob/ob, and obese ob/ob mice before and after 6 days of IH to determine how obesity and intermittent hypoxia interact to affect cardiac function independent of leptin signaling.

Results:

Calorically-restricting ob/ob mice for 4 weeks prior to IH exposure prevented weight gain (−2.1 ± 1.4 …

A Potential Role For Substance P In West Nile Virus Neuropathogenesis, Shannon E Ronca, Sarah M Gunter, Rebecca Berry Kairis, Allison Lino, Jonathan Romero, Robia G Pautler, Alan Nimmo, Kristy O Murray

Faculty, Staff and Students Publications

Of individuals who develop West Nile neuroinvasive disease (WNND), ~10% will die and >40% will develop long-term complications. Current treatment recommendations solely focus on supportive care; therefore, we urgently need to identify novel and effective therapeutic options. We observed a correlation between substance P (SP), a key player in neuroinflammation, and its receptor Neurokinin-1 (NK1R). Our study in a wild-type BL6 mouse model found that SP is upregulated in the brain during infection, which correlated with neuroinvasion and damage to the blood−brain barrier. Blocking the SP/NK1R interaction beginning at disease onset modestly improved survival and prolonged time to death in …

Circadian Clock Controls Rhythms In Ketogenesis By Interfering With Ppar Alpha Transcriptional Network, Volha Mezhnina, Oghogho P. Ebeigbe, Nikkhil Velingkaar, Allan Poe, Yana I. Sandlers, Roman Kondratov

Biological, Geological, and Environmental Faculty Publications

Ketone bodies are energy-rich metabolites and signaling molecules whose production is mainly regulated by diet. Caloric restriction (CR) is a dietary intervention that improves metabolism and extends longevity across the taxa. We found that CR induced high -amplitude daily rhythms in blood ketone bodies (beta-hydroxybutyrate [beta OHB]) that correlated with liver beta OHB level. Time-restricted feeding, another periodic fasting-based diet, also led to rhythmic beta OHB but with reduced amplitude. CR induced strong circadian rhythms in the expression of fatty acid oxidation and ketogenesis genes in the liver. The transcriptional factor peroxisome-proliferator-activated-receptor alpha (PPAR alpha) and its transcriptional target hepatokine …

Head Removal Enhances Planarian Electrotaxis, Ziad Sabry , '21, Rui Wang, A. Jahromi, Christina Rabeler, W. B. Kristan Iii, Eva-Maria S. Collins

Biology Faculty Works

Certain animal species utilize electric fields for communication, hunting and spatial orientation. Freshwater planarians move toward the cathode in a static electric field (cathodic electrotaxis). This planarian behavior was first described by Raymond Pearl more than a century ago. However, planarian electrotaxis has received little attention since, and the underlying mechanisms and evolutionary significance remain unknown. To close this knowledge gap, we developed an apparatus and scoring metrics for automated quantitative and mechanistic studies of planarian behavior upon exposure to a static electric field. Using this automated setup, we characterized electrotaxis in the planarian Dugesia japonica and found that this …

Estimating R0 From Early Exponential Growth: Parallels Between 1918 Influenza And 2020 Sars-Cov-2 Pandemics, Grant Foster, Bret D. Elderd, Robert L. Richards, Tad Dallas

Faculty Publications

The large spatial scale, geographical overlap, and similarities in transmission mode between the 1918 H1N1 influenza and 2020 SARS-CoV-2 pandemics together provide a novel opportunity to investigate relationships between transmission of two different diseases in the same location. To this end, we use initial exponential growth rates in a Bayesian hierarchical framework to estimate the basic reproductive number, R₀, of both disease outbreaks in a common set of 43 cities in the United States. By leveraging multiple epidemic time series across a large spatial area, we are able to better characterize the variation in R₀ across the …

Gamma Protocadherin Synaptic Localization And Intracellular Trafficking Is Consistent With Distinct Adhesive And Anti-Adhesive Roles In Development, Nicole Lamassa

Dissertations, Theses, and Capstone Projects

Clustered protocadherins (Pcdhs) constitute a family of cell adhesion molecules with approximately 60 Pcdh genes clustered in a 1 MB locus on chromosome 5q31 in humans. The Pcdh gene cluster is subdivided into α, β, and γ subclusters which encode related proteins. Individual neurons activate different subsets of Pcdh-α, Pcdh-β and Pcdh-γ genes by epigenetic mechanisms to generate distinct Pcdh adhesive units expressed by each neuron. This is thought to serve as a “surface barcode” for single-cell identity and synaptic recognition in the nervous system. The actual role for Pcdhs in neural development is still relatively unknown and different roles …

Function Of Atm And Msh2 During Dna Repair And Recombination, Emily Sible

Dissertations, Theses, and Capstone Projects

Class switch recombination (CSR) produces secondary immunoglobulin isotypes and requires AID-dependent DNA deamination of intronic switch (S) regions within the immunoglobulin heavy chain (Igh) gene locus. Non-canonical repair of deaminated DNA by mismatch repair (MMR) or base excision repair (BER) creates DNA breaks that permit recombination between distal S regions. ATM-dependent phosphorylation of AID at serine-38 (pS38-AID) promotes its interaction with APE1, a BER protein, suggesting that ATM regulates CSR through BER. However, pS38-AID may also function in MMR during CSR, although the mechanism remains unknown. To examine whether ATM modulates BER- and/or MMR-dependent CSR, Atm^-/- mice …

Epigenetic Influences Of Mobile Genetic Elements On Ciliate Genome Architecture And Evolution, Caitlin M. Timmons, Shahed U.A. Shazib, Laura A. Katz

Biological Sciences: Faculty Publications

Mobile genetic elements (MGEs) are transient genetic material that can move either within a single organism's genome or between individuals or species. While historically considered “junk” DNA (i.e., deleterious or at best neutral), more recent studies reveal the potential adaptive advantages MGEs provide in lineages across the tree of life. Ciliates, a group of single-celled microbial eukaryotes characterized by nuclear dimorphism, exemplify how epigenetic influences from MGEs shape genome architecture and patterns of molecular evolution. Ciliate nuclear dimorphism may have evolved as a response to transposon invasion and ciliates have since co-opted transposons to carry out programmed DNA deletion. Another …

Taxon-Rich Transcriptomics Supports Higher-Level Phylogeny And Major Evolutionary Trends In Foraminifera, Roberto Sierra, Florian Mauffrey, Joana Cruz, Maria Holzmann, Andrew J. Gooday, Xyrus Maurer-Alcalá, Rabindra Thakur, Mattia Greco, Agnes K.M. Weiner, Laura A. Katz, Jan Pawlowski

Biological Sciences: Faculty Publications

Foraminifera, classified in the supergroup Rhizaria, are a common and highly diverse group of mainly marine protists. Despite their evolutionary and ecological importance, only limited genomic data (one partial genome and nine transcriptomic datasets) have been published for this group. Foraminiferal molecular phylogeny is largely based on 18S rRNA gene sequence analysis. However, due to highly variable evolutionary rates of substitution in ribosomal genes plus the existence of intragenomic variation at this locus, the relationships between and within foraminiferal classes remain uncertain. We analyze transcriptomic data from 28 species, adding 19 new species to the previously published dataset, including members …

Diversity Of Reptile Sex Chromosome Evolution Revealed By Cytogenetic And Linked-Read Sequencing, Ze-Xian Zhu, Kazumi Matsubara, Foyez Shams, Jason Dobry, Erik Wapstra, Tony Gamble, Stephen D. Sarre, Arthur Georges, Jennifer A. Marshall Graves, Qi Zhou, Tariq Ezaz

Biological Sciences Faculty Research and Publications

Reptile sex determination is attracting much attention because the great diversity of sex-determination and dosage compensation mechanisms permits us to approach fundamental questions about mechanisms of sex chromosome turnover. Recent studies have made significant progress in better understanding diversity and conservation of reptile sex chromosomes, with however no reptile master sex determination genes identified. Here we describe an integrated genomics and cytogenetics pipeline, combining probes generated from the microdissected sex chromosomes with transcriptome and genome sequencing to explore the sex chromosome diversity in non-model Australian reptiles. We tested our pipeline on a turtle, two species of geckos, and a monitor …

Genetic Determinants Of Carotenoid Pigmentation In The Opportunistic Pathogen Mycobacterium Kansasii, Niklas Janisch

Dissertations, Theses, and Capstone Projects

Mycobacterium kansasii (Mk) is an opportunistic pulmonary pathogen causing infections, predominantly in immunocompromised people, with symptoms similar to those caused by its close relative Mycobacterium tuberculosis (Mt). In contrast to the latter, little work has been done on Mk genetics and even less on its defining characteristic of photochromogenicity, the controlled expression of carotenoid pigments in response to light exposure.

This work represents major progress in the investigation of pigmentation-related genetic factors in Mk. We report the creation of a large-scale, random transposon-insertion mutant library of Mk and its subsequent screening for mutants with an aberration in the …

Generation Of Mycobacterium Smegmatis Model Systems For Testing Inhibitors Of The Mycobactin Siderophore Of Mycobacterium Tuberculosis, Gabrielle A. Germain

Dissertations, Theses, and Capstone Projects

Mycobacterium tuberculosis (Mtb) is the pathogenic bacterium causative of tuberculosis. According to the 2021 World Health Organization (WHO) Global Tuberculosis (TB) Report, there were approximately 5.8 million TB cases in 2020, and 1.3 million TB deaths among HIV negative people in that year. The rise of multi-drug resistant Mtb strains has increased the need for more potent microbials against this pathogen. Biosynthesis of iron scavenging molecules, known as siderophores (e.g., mycobactin and carboxymycobactin), has been identified as a potential drug target candidate since iron acquisition has been directly linked to the survival and virulence of Mtb. Salicyl-AMS (Sal-AMS) is …

Clustered Protocadherins Ubiquitination And Phosphorylation Regulates Surface Expression, Albert Ptashnik

Dissertations, Theses, and Capstone Projects

Clustered protocadherins (Pcdhs) are a family of 60 adhesion-like molecules forming a neural barcode. In vertebrate neurons, 60 Pcdhs are coded by a large gene cluster. Numerous axons in the cluster are coding for the different extracellular, transmembrane, variable portion of the cytoplasmic and constant cytoplasmic domains where their expression is controlled epigenetically. These proteins mediate interactions between axons, dendrites, and glial cells during neural development. Yet, Pcdhs are not strictly adhesion molecules. In the amacrine cells of the retina, Pcdhs promote avoidance of the same cell dendrites, where in the cortex Pcdhs promote interactions between dendrites and astrocytes. In …

Proteome Of The Wood Decay Fungus Fomitopsis Pinicola Is Altered By Substrate, Grzegorz Sabat, Steven Ahrendt, Baojun Wu, Jill Gaskell, Benjamin W. Held, Cristina Toapanta, Thu V. Vuong, Anna Lipzen, Jiwei Zhang, Jonathan S. Schilling, Emma Master, Igor V. Grigoriev, Robert A. Blanchette, David S. Hibbett, Jennifer Bhatnagar, Daniel Cullen

Biology

The brown rot fungus Fomitopsis pinicola efficiently depolymerizes wood cellulose via the combined activities of oxidative and hydrolytic enzymes. Mass spectrometric analyses of culture filtrates identified specific proteins, many of which were differentially regulated in response to substrate composition.

Role Of The G Protein Beta Gamma Subunits In Serotonin Transporter Dynamics, Nora Awadallah

Dissertations, Theses, and Capstone Projects

Serotonin is a vital neurotransmitter and hormone with significant roles in almost every organ system. In the central nervous system, serotonin mediates physiological functions that in turn guide behavior and mood. Here, serotonin is released from serotonergic neurons and exerts its effects through serotonin receptors. Regulation of serotonin neurotransmission is important for the maintenance of its physiological functions; thus, extracellular serotonin must be sequestered to limit the intensity and duration of serotonin transmission. Disproportionate transmission is strongly linked with neurological and psychiatric ailments.

Extracellular serotonin levels are primarily mediated by the serotonin transporter (SERT), a critically important plasma membrane protein …

Development Of The Seqcode: A Proposed Nomenclatural Code For Uncultivated Prokaryotes With Dna Sequences As Type, William Whitman, Maria Chuvochina, Brian P. Hedlund, Philip Hugenholtz, Konstantinos T. Konstantinidis, Alison E. Murray, Marike Palmer, Donovan H. Parks, Anna-Louise Reysenbach, Multiple Additional Authors

Biology Faculty Publications and Presentations

Over the last fifteen years, genomics has become fully integrated into prokaryotic systematics. The genomes of most type strains have been sequenced, genome sequence similarity is widely used for delineation of species, and phylogenomic methods are commonly used for classification of higher taxonomic ranks. Additionally, environmental genomics has revealed a vast diversity of as-yet-uncultivated taxa. In response to these developments, a new code of nomenclature, the Code of Nomenclature of Prokaryotes Described from Sequence Data (SeqCode), has been developed over the last two years to allow naming of Archaea and Bacteria using DNA sequences as the nomenclatural types. The …

Low Soil Nitrogen And Moisture Limit The Expansion Of The Invasive Grass, Megathyrsus Maximus (Guinea Grass) In Semi-Arid Soils, E. Penelope Holland, Vanessa Thomas, Pushpa G. Soti

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The goal of this study was to predict the range expansion potential of an invasive forage grass, Guinea grass (Megathyrsus maximus). We collected rhizosphere soil samples of M. maximus and coexisting species from 150 different locations and analysed them for soil properties. We estimated the probability of M. maximus presence as a function of soil moisture, organic matter, pH, salinity, total N, and CN ratio using logistic regression. Presence of M. maximus was associated with higher soil moisture, higher organic matter, pH, and nitrogen, but lower salinity and CN ratio. Soil nitrogen and moisture …

The Insulin Receptor Regulates The Persistence Of Mechanical Nociceptive Sensitization In Flies And Mice, Tatiana V Karpinets, Xiaogang Wu, Travis Solley, Molly B El Alam, Travis T Sims, Kyoko Yoshida-Court, Erica Lynn, Mustapha Ahmed-Kaddar, Greyson Biegert, Jingyan Yue, Xingzhi Song, Huandong Sun, Joseph F Petrosino, Melissa P Mezzari, Pablo Okhuysen, Patricia J Eifel, Anuja Jhingran, Lilie L Lin, Kathleen M Schmeler, Lois Ramondetta, Nadim Ajami, Robert R Jenq, Andrew Futreal, Jianhua Zhang, Ann H Klopp, Lauren E Colbert

Faculty, Staff and Student Publications

Early phase diabetes is often accompanied by pain sensitization. In Drosophila, the insulin receptor (InR) regulates the persistence of injury-induced thermal nociceptive sensitization. Whether Drosophila InR also regulates the persistence of mechanical nociceptive sensitization remains unclear. Mice with a sensory neuron deletion of the insulin receptor (Insr) show normal nociceptive baselines; however, it is uncertain whether deletion of Insr in nociceptive sensory neurons leads to persistent nociceptive hypersensitivity. In this study, we used fly and mouse nociceptive sensitization models to address these questions. In flies, InR mutants and larvae with sensory neuron-specific expression of RNAi …

Seqcode: A Nomenclatural Code For Prokaryotes Described From Sequence Data, Brian P. Hedlund, Maria Chuvochina, Philip Hugenholtz, Konstantinos T. Konstantinidis, Alison E. Murray, Marike Palmer, Donovan H. Parks, Alexander J. Probst, Anna-Louise Reysenbach, Multiple Additional Authors

Biology Faculty Publications and Presentations

Most prokaryotes are not available as pure cultures and therefore ineligible for naming under the rules and recommendations of the International Code of Nomenclature of Prokaryotes (ICNP). Here we summarize the development of the SeqCode, a code of nomenclature under which genome sequences serve as nomenclatural types. This code enables valid publication of names of prokaryotes based upon isolate genome, metagenome-assembled genome or single-amplified genome sequences. Otherwise, it is similar to the ICNP with regard to the formation of names and rules of priority. It operates through the SeqCode Registry (https://seqco.de/), a registration portal through which names and …

Limited Utility Of Structural Mri To Identify The Epileptogenic Zone In Young Children With Tuberous Sclerosis, Maaike Nijman, Edward Yang, Camilo Jaimes, Anna K Prohl, Mustafa Sahin, Darcy A Krueger, Joyce Y Wu, Hope Northrup, Scellig S D Stone, Joseph R Madsen, Aria Fallah, Jeffrey P Blount, Howard L Weiner, Leslie Grayson, E Martina Bebin, Brenda E Porter, Simon K Warfield, Sanjay P Prabhu, Jurriaan M Peters, Tacern Study Group

Faculty, Staff and Students Publications

BACKGROUND AND PURPOSE: The success of epilepsy surgery in children with tuberous sclerosis complex (TSC) hinges on identification of the epileptogenic zone (EZ). We studied structural MRI markers of epileptogenic lesions in young children with TSC.

METHODS: We included 26 children with TSC who underwent epilepsy surgery before the age of 3 years at five sites, with 12 months or more follow-up. Two neuroradiologists, blinded to surgical outcome data, reviewed 10 candidate lesions on preoperative MRI for characteristics of the tuber (large affected area, calcification, cyst-like properties) and of focal cortical dysplasia (FCD) features (cortical malformation, gray-white matter junction blurring, …

Sustained Deep-Tissue Voltage Recording Using A Fast Indicator Evolved For Two-Photon Microscopy, Zhuohe Liu, Xiaoyu Lu, Vincent Villette, Yueyang Gou, Kevin L Colbert, Shujuan Lai, Sihui Guan, Michelle A Land, Jihwan Lee, Tensae Assefa, Daniel R Zollinger, Maria M Korympidou, Anna L Vlasits, Michelle M Pang, Sharon Su, Changjia Cai, Emmanouil Froudarakis, Na Zhou, Saumil S Patel, Cameron L Smith, Annick Ayon, Pierre Bizouard, Jonathan Bradley, Katrin Franke, Thomas R Clandinin, Andrea Giovannucci, Andreas S Tolias, Jacob Reimer, Stéphane Dieudonné, François St-Pierre

Faculty, Staff and Students Publications

Genetically encoded voltage indicators are emerging tools for monitoring voltage dynamics with cell-type specificity. However, current indicators enable a narrow range of applications due to poor performance under two-photon microscopy, a method of choice for deep-tissue recording. To improve indicators, we developed a multiparameter high-throughput platform to optimize voltage indicators for two-photon microscopy. Using this system, we identified JEDI-2P, an indicator that is faster, brighter, and more sensitive and photostable than its predecessors. We demonstrate that JEDI-2P can report light-evoked responses in axonal termini of Drosophila interneurons and the dendrites and somata of amacrine cells of isolated mouse retina. JEDI-2P …

Combined Impacts Of Co2 Enrichment And Water Stress On Growth And Physiology Of Plants Inoculated With An Acc Deaminase Producing Rhizobacterium, Shaijal Babu Ppoyil

Dissertations

This study assessed the water stress mitigating effects of elevated CO₂ on Chloris gayana Kunth cv. Katambora (Rhodes grass) and Medicago sativa L. cv. SuperFast (alfalfa) plants, and how the seed inoculation with one of the ACC deaminase producing plant growth promoting rhizobacterium (PGPR) supplemented the stand-alone plant drought stress mitigating effects of elevated CO₂, under different growing conditions in the United Arab Emirates (UAE). Multiple growth and physiology related variables were measured from the plants in response to different treatment combinations made of CO₂, watering treatments (WT), and PGPR, based on the research design …

The Utilization Of Crispr/Cas9 In Monogenic Disorders Authors, Shauna M. Mellor

Spectra Undergraduate Research Journal

This paper is a literature review of various scientific research papers, exploring the recent scientific advancement in the field of genetic engineering. The research presented is a foundational tool, building awareness on the implications of CRISPR/ Cas9 technology. CRISPR/ Cas9 was first discovered through the study of bacterial immune systems, fighting against viral infections. Manipulation of the Cas9 protein would eventually lead to target specific, gene-altering medicines for human organisms. CRISPR/ Cas 9 technology has begun to show promise as an effective treatment for certain monogenic disorders. Despite this, time is required before its efficacy as a proven genetic treatment …

Brainless But Smart: Investigating Cognitive-Like Behaviors In The Acellular Slime Mold Physarum Polycephalum, Subash Kusum Ray

Dissertations

Evolutionary pressures to improve fitness, have enabled living systems to make adaptive decisions when faced with heterogeneous and changing environmental and physiological conditions. This dissertation investigated the mechanisms of how environmental and physiological factors affect the behaviors of non-neuronal organisms. The acellular slime mold Physarum polycephalum was used as the model organism, which is a macroscopic, unicellular organism, that self-organizes into a network of intersecting tubules. Without using neurons, P. polycephalum can solve labyrinth mazes, build efficient tubule networks, and make adaptive decisions when faced with complicated trade-offs, such as between food quality and risk, speed and accuracy, and exploration …

Flexibility Vs Consistency: Quantifying Differences In Neuromodulatory Elicited Patterns Of Activity, Elizabeth M. Cronin

Dissertations

Central pattern generating circuits underly fundamental behaviors such as respiration or locomotion and are under the influence of neuromodulators. The presence of neuromodulators is thought to confer flexibility to these circuits to generate distinct patterns of activity to meet distinct behavioral needs. Network output flexibility can be achieved by distinct classes of neuromodulators, those which have convergent cellular actions but divergent circuit actions or by those which have divergent cellular actions but convergent circuit actions.

Both classes of neuromodulator exist in the stomatogastric nervous system of the crab Cancer borealis and influence the activity of a central pattern generating circuit …