Showing 61 - 70 of 116 Items

Brain activity patterns underlying memory confidence

Date: 2022-04-01

Creator: Syanah C. Wynn, Erika Nyhus

Access: Open access

The primary aim of this review is to examine the brain activity patterns that are related to subjectively perceived memory confidence. We focus on the main brain regions involved in episodic memory: the medial temporal lobe (MTL), prefrontal cortex (PFC), and posterior parietal cortex (PPC), and relate activity in their subregions to memory confidence. How this brain activity in both the encoding and retrieval phase is related to (subsequent) memory confidence ratings will be discussed. Specifically, encoding related activity in MTL regions and ventrolateral PFC mainly shows a positive linear increase with subsequent memory confidence, while dorsolateral and ventromedial PFC activity show mixed patterns. In addition, encoding-related PPC activity seems to only have indirect effects on memory confidence ratings. Activity during retrieval in both the hippocampus and parahippocampal cortex increases with memory confidence, especially during high-confident recognition. Retrieval-related activity in the PFC and PPC show mixed relationships with memory confidence, likely related to post-retrieval monitoring and attentional processes, respectively. In this review, these MTL, PFC, and PPC activity patterns are examined in detail and related to their functional roles in memory processes. This insight into brain activity that underlies memory confidence is important for our understanding of brain–behaviour relations and memory-guided decision making. © 2022 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.


Efficient and rapid identification of Candida albicans allelic status using SNP-RFLP

Date: 2009-11-01

Creator: Anja Forche, Musetta Steinbach, Judith Berman

Access: Open access

Candida albicans is the most prevalent opportunistic fungal pathogen in the clinical setting, causing a wide spectrum of diseases ranging from superficial mucosal lesions to life-threatening deep-tissue infections. Recent studies provide strong evidence that C. albicans possesses an arsenal of genetic mechanisms promoting genome plasticity and that it uses these mechanisms under conditions of nutritional or antifungal drug stress. Two microarray-based methods, single nucleotide polymorphism (SNP) and comparative genome hybridization arrays, have been developed to study genome changes in C. albicans. However, array technologies can be relatively expensive and are not available to every laboratory. In addition, they often generate more data than needed to analyze specific genomic loci or regions. Here, we have developed a set of SNP-restriction fragment length polymorphism (RFLP) (or PCR-RFLP) markers, two per chromosome arm, for C. albicans. These markers can be used to rapidly and accurately detect large-scale changes in the C. albicans genome including loss of heterozygosity (LOH) at single loci, across chromosome arms or across whole chromosomes. Furthermore, skewed SNP-RFLP allelic ratios are indicative of trisomy at heterozygous loci. While less comprehensive than array-based approaches, we propose SNP-RFLP as an inexpensive, rapid, and reliable method to screen strains of interest for possible genome changes. © 2009 Federation of European Microbiological Societies.


Erratum: The 'obligate diploid' Candida albicans forms mating-competent haploids (Nature (2013) 494 (55-59) DOI: 10.1038/nature11865)

Date: 2016-02-11

Creator: Meleah A. Hickman, Guisheng Zeng, Anja Forche, Matthew P. Hirakawa, Darren, Abbey, Benjamin D. Harrison, Yan Ming Wang, Ching Hua Su, Richard J. Bennett, Yue Wang, Judith Berman

Access: Open access



Ploidy variation in fungi: Polyploidy, aneuploidy, and genome evolution

Date: 2017-07-01

Creator: Robert T. Todd, Anja Forche, Anna Selmecki

Access: Open access

The ability of an organism to replicate and segregate its genome with high fidelity is vital to its survival and for the production of future generations. Errors in either of these steps (replication or segregation) can lead to a change in ploidy or chromosome number. While these drastic genome changes can be detrimental to the organism, resulting in decreased fitness, they can also provide increased fitness during periods of stress. A change in ploidy or chromosome number can fundamentally change how a cell senses and responds to its environment. Here, we discuss current ideas in fungal biology that illuminate how eukaryotic genome size variation can impact the organism at a cellular and evolutionary level. One of the most fascinating observations from the past 2 decades of research is that some fungi have evolved the ability to tolerate large genome size changes and generate vast genomic heterogeneity without undergoing canonical meiosis.


Miniature of The Modulatory Role of the Hyperpolarization-Activated Inward Current and Adenosine A1 - Dopamine D1 Receptor Heteromers on Spinal Locomotor Activity
The Modulatory Role of the Hyperpolarization-Activated Inward Current and Adenosine A1 - Dopamine D1 Receptor Heteromers on Spinal Locomotor Activity
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      Date: 2021-01-01

      Creator: Andrew Moore

      Access: Access restricted to the Bowdoin Community



        Miniature of Ultrasonic vocalization playback as an affective assay at both neural and behavioral levels: Implications for understanding adversity-induced emotional dysfunction
        Ultrasonic vocalization playback as an affective assay at both neural and behavioral levels: Implications for understanding adversity-induced emotional dysfunction
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            Date: 2023-01-01

            Creator: Sydney M Bonauto

            Access: Access restricted to the Bowdoin Community



              Miniature of Directed Information Flow During Episodic Memory Retrieval at Theta Frequency
              Directed Information Flow During Episodic Memory Retrieval at Theta Frequency
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              • Restriction End Date: 2027-06-01

                Date: 2022-01-01

                Creator: Patrick F. Bloniasz

                Access: Access restricted to the Bowdoin Community



                  Miniature of Effect of Mindfulness Meditation on Long-Term Memory
                  Effect of Mindfulness Meditation on Long-Term Memory
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                      Date: 2016-05-01

                      Creator: William Andrew Engel

                      Access: Access restricted to the Bowdoin Community



                        Dietary diversity correlates with the neuromodulatory capacity of the stomatogastric nervous system in three species of majoid crabs

                        Date: 2023-01-01

                        Creator: Elise Martin

                        Access: Open access

                        This project sought to answer the following question: what is the relationship between the extent of neuromodulation in a nervous system, and the behavioral demands on that system? A well-characterized CPG neuronal circuit in decapod crustaceans, the stomatogastric nervous system (STNS), was used as a model circuit to answer this question. The stomatogastric ganglion (STG) in the STNS is responsible for muscular contractions in the stomach that aid in digestion. It has been shown that the neural networks in the STG are subject to neuromodulation. One feature of neuromodulation is that it enables circuit flexibility, which confers upon a system the ability to produce variable outputs in response to specific physiological demands. It was hypothesized that opportunistic feeders require more extensively modulated digestive systems compared to exclusive feeders, because opportunistic feeders require a greater variety of digestive outputs to digest their varied diets. In this study, Chionoecetes opilio and Libinia emarginata, the opportunistic feeders, showed greater neuromodulatory capacity of the STNS than Pugettia producta, the exclusive feeder. The hypothesis that neuromodulatory capacity of the STNS correlates with dietary diversity was supported. The results detailed in this study lend credence to the idea that evolutionary basis for neuromodulatory capacity of a system is related to the behavioral demands on that system.


                        Effects of Picrotoxin Application on the Cardiac Ganglion of the American Lobster, Homarus americanus

                        Date: 2023-01-01

                        Creator: John T Woolley

                        Access: Open access

                        Picrotoxin (PTX) has been employed extensively as a tool within the crustacean stomatogastric nervous system (STNS) for its efficacy in blocking K+ and Cl+ currents gated by both GABA and glutamate. Through blocking some currents in the STNS, PTX allows for examination of other components without their presence. However, effects of PTX are relatively unknown within the lobster’s cardiac ganglion (CG). As an incredibly small nervous system of only nine neurons, the lobster CG presents an excellent model system for studying neural circuits. Given that the chemical synapses in the CG are mediated by glutamate, the present study aimed to investigate the action of PTX in the lobster CG with the intent of better understanding its pharmacological impacts as a potential tool for studying the system. Therefore, this study aimed to establish the effects of PTX on CG responses to the application of exogenous GABA or glutamate. When data from both modulators were pooled, PTX applied at a concentration of 10-5M had significant effects on burst duration but not duty cycle or burst frequency of the CG. PTX did suppress GABA (5x10-5M) mediated inhibition of burst duration and duty cycle. PTX did not have any significant effects on burst duration, duty cycle, or frequency compared to exogenous glutamate application. These results indicate that glutamatergic inhibitory synapses are not present in the CG and PTX partially suppresses only GABAergic responses in this system.