Ploski, Jonathan E.
Permanent URI for this collectionhttps://hdl.handle.net/10735.1/3701
Jonathan Ploski's research interests include:
- Molecular and biochemical mechanisms of synaptic plasticity
- Emotional learning and memory
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Item Is Arc mRNA Unique: A Search For mRNAs That Localize to the Distal Dendrites of Dentate Gyrus Granule Cells Following Neural Activity(Frontiers Media Sa) de Solis, Christopher A.; Morales, Anna A.; Hosek, Matthew P.; Partin, Alex C.; Ploski, Jonathan E.; de Solis, Christopher A.; Morales, Anna A.; Hosek, Matthew P.; Ploski, Jonathan E.There have been several attempts to identify which RNAs are localized to dendrites; however, no study has determined which RNAs localize to the dendrites following the induction of synaptic activity. We sought to identify all RNA transcripts that localize to the distal dendrites of dentate gyrus granule cells following unilateral high frequency stimulation of the perforant pathway (pp-HFS) using Sprague Dawley rats. We then utilized laser microdissection (LMD) to very accurately dissect out the distal 2/3rds of the molecular layer (ML), which contains these dendrites, without contamination from the granule cell layer, 2 and 4 h post pp-HFS. Next, we purified and amplified RNA from the ML and performed an unbiased screen for 27,000 RNA transcripts using Affymetrix microarrays. We determined that Activity Regulated Cytoskeletal Protein (Arc/Arg3.1) mRNA, exhibited the greatest fold increase in the ML at both timepoints 2 and 4 h). In total, we identified 31 transcripts that increased their levels within the ML following pp-HFS across the two timepoints. Of particular interest is that one of these identified transcripts was an unprocessed micro-RNA pri-miR132). Fluorescent in situ hybridization and qRT-PCR were used to confirm some of these candidate transcripts. Our data indicate Arc is a unique activity dependent gene, due to the magnitude that its activity dependent transcript localizes to the dendrites. Our study determined other activity dependent transcripts likely localize to the dendrites following neural activity, but do so with lower efficiency compared to Arc.Item The Production of Viral Vectors Designed to Express Large and Difficult to Express Transgenes Within Neurons(BioMed Central) Holehonnur, Roopashri; Lella, Srihari K.; Ho, Anthony; Luong, Jonathan A.; Ploski, Jonathan E; Holehonnur, Roopashri; Lella, Srihari K.; Ho, Anthony; Luong, Jonathan A.; Ploski, Jonathan EBackground: Viral vectors are frequently used to deliver and direct expression of transgenes in a spatially and temporally restricted manner within the nervous system of numerous model organisms. Despite the common use of viral vectors to direct ectopic expression of transgenes within the nervous system, creating high titer viral vectors that are capable of expressing very large transgenes or difficult to express transgenes imposes unique challenges. Here we describe the development of adeno-associated viruses (AAV) and lentiviruses designed to express the large and difficult to express GluN2A or GluN2B subunits of the N-methyl-D-aspartate receptor (NMDA) receptor, specifically within neurons.; Results: We created a number of custom designed AAV and lentiviral vectors that were optimized for large transgenes, by minimizing DNA sequences that were not essential, utilizing short promoter sequences of 8 widely used promoters (RSV, EFS, TRE3G, 0.4aCaMKII, 1.3aCaMKII, 0.5Synapsin, 1.1Synapsin and CMV) and utilizing a very short (~75 bps) 3' untranslated sequence. Not surprisingly these promoters differed in their ability to express the GluN2 subunits, however surprisingly we found that the neuron specific synapsin and aCaMKII, promoters were incapable of conferring detectable expression of full length GluN2 subunits and detectable expression could only be achieved from these promoters if the transgene included an intron or if the GluN2 subunit transgenes were truncated to only include the coding regions of the GluN2 transmembrane domains.; Conclusions: We determined that viral packaging limit, transgene promoter and the presence of an intron within the transgene were all important factors that contributed to being able to successfully develop viral vectors designed to deliver and express GluN2 transgenes in a neuron specific manner. Because these vectors have been optimized to accommodate large open reading frames and in some cases contain an intron to facilitate expression of difficult to express transgenes, these viral vectors likely could be useful for delivering and expressing many large or difficult to express transgenes in a neuron specific manner.;Item Emotional Modulation of Synapses, Circuits and Memory(Frontiers Research Foundation) Ploski, Jonathan E.; McIntyre, Christa K.Item Abnormal Emotional Learning in a Rat Model of Autism Exposed to Valproic Acid in Utero(Frontiers Research Foundation) Banerjee, Anwesha; Engineer, Crystal T.; Sauls, Bethany L.; Morales, Anna A.; Ploski, Jonathan E.\\Kilgard, Michael P.; Kilgard, Michael P.Autism Spectrum Disorders (ASD) are complex neurodevelopmental disorders characterized by repetitive behavior and impaired social communication and interactions. Apart from these core symptoms, a significant number of ASD individuals display higher levels of anxiety and some ASD individuals exhibit impaired emotional learning. We therefore sought to further examine anxiety and emotional learning in an environmentally induced animal model of ASD that utilizes the administration of the known teratogen, valproic acid (VPA) during gestation. Specifically we exposed dams to one of two different doses of VPA (500 and 600 mg/kg) or vehicle on day 12.5 of gestation and examined the resultant progeny. Our data indicate that animals exposed to VPA in utero exhibit enhanced anxiety in the open field test and normal object recognition memory compared to control animals. Animals exposed to 500 mg/kg of VPA displayed normal acquisition of auditory fear conditioning, and exhibited reduced extinction of fear memory and normal litter survival rates as compared to control animals. We observed that animals exposed to 600 mg/kg of VPA exhibited a significant reduction in the acquisition of fear conditioning, a significant reduction in social interaction and a significant reduction in litter survival rates as compared to control animals. VPA (600 mg/kg) exposed animals exhibited similar shock sensitivity and hearing as compared to control animals indicating the fear conditioning deficit observed in these animals was not likely due to sensory deficits, but rather due to deficits in learning or memory retrieval. In conclusion, considering that progeny from dams exposed to rather similar doses of VPA exhibit striking differences in emotional learning, the VPA model may serve as a useful tool to explore the molecular and cellular mechanisms that contribute to not only ASD, but also emotional learning.Item Adeno-associated viral serotypes produce differing titers and differentially transduce neurons within the rat basal and lateral amygdala(BioMed Central) Holehonnur, Roopashri; Luong, Jonathan A.; Chaturvedi, Dushyant; Ho, Anthony; Lella, Srihari K.; Hosek, Matthew P.; Ploski, Jonathan E.Background: In recent years, there has been an increased interest in using recombinant adeno-associated viruses (AAV) to make localized genetic manipulations within the rodent brain. Differing serotypes of AAV possess divergent capsid protein sequences and these variations greatly influence each serotype's ability to transduce particular cell types and brain regions. We therefore aimed to determine the AAV serotype that is optimal for targeting neurons within the Basal and Lateral Amygdala (BLA) since the transduction efficiency of AAV has not been previously examined within the BLA. This region is desirable to genetically manipulate due to its role in emotion, learning & memory, and numerous psychiatric disorders. We accomplished this by screening 9 different AAV serotypes (AAV2/1, AAV2/2, AAV2/5, AAV2/7, AAV2/8, AAV2/9, AAV2/rh10, AAV2/DJ and AAV2/DJ8) designed to express red fluorescent protein (RFP) under the regulation of an alpha Ca2+/calmodulin-dependent protein kinase II promoter (aCaMKII).; Results: We determined that these serotypes produce differing amounts of virus under standard laboratory production. Notably AAV2/2 consistently produced the lowest titers compared to the other serotypes examined. These nine serotypes were bilaterally infused into the rat BLA at the highest titers achieved for each serotype and at a normalized titer of 7.8E + 11 GC/ml. Twenty one days following viral infusion the degree of transduction was quantitated throughout the amygdala. These viruses exhibited differential transduction of neurons within the BLA. AAV2/7 exhibited a trend toward having the highest efficiency of transduction and AAV2/5 exhibited significantly lower transduction efficiency as compared to the serotypes examined. AAV2/5's decreased ability to transduce BLA neurons correlates with its significantly different capsid protein sequences as compared to the other serotypes examined.; Conclusions: For laboratories producing their own recombinant adeno-associated viruses, the use of AAV2/2 is likely less desirable since AAV2/2 produces significantly lower titers than many other serotypes of AAV. Numerous AAV serotypes appear to efficiently transduce BLA neurons, with the exception of AAV2/5. Taking into consideration the ability of certain serotypes to achieve high titers and transduce BLA neurons well, in our hands AAV2/DJ8 and AAV2/9 appear to be ideal serotypes to use when targeting neurons within the BLA.;