title: Characterization of the rapid transcriptional response to long-term sensitization training in Aplysia californica.
abstract: We used a custom-designed microarray and quantitative PCR to characterize the rapid transcriptional response to long-term sensitization training in the marine mollusk Aplysia californica. Aplysia were exposed to repeated noxious shocks to one side of the body, a procedure known to induce a long-lasting, transcription-dependent increase in reflex responsiveness that is restricted to the side of training. One hour after training, pleural ganglia from the trained and untrained sides of the body were harvested; these ganglia contain the sensory nociceptors which help mediate the expression of long-term sensitization memory. Microarray analysis from 8 biological replicates suggests that long-term sensitization training rapidly regulates at least 81 transcripts. We used qPCR to test a subset of these transcripts and found that 83% were confirmed in the same samples, and 86% of these were again confirmed in an independent sample. Thus, our new microarray design shows strong convergent and predictive validity for analyzing the transcriptional correlates of memory in Aplysia. Fully validated transcripts include some previously identified as regulated in this paradigm (ApC/EBP and ApEgr) but also include novel findings. Specifically, we show that long-term sensitization training rapidly up-regulates the expression of transcripts which may encode Aplysia homologs of a C/EBPγ transcription factor, a glycine transporter (GlyT2), and a vacuolar-protein-sorting-associated protein (VPS36).
authors.affiliation: Neuroscience Program, Dominican University, River Forest, IL, United States.
authors.forename: Samantha
authors.initials: S
authors.lastname: Herdegen
authors.affiliation: Neuroscience Program, Dominican University, River Forest, IL, United States.
authors.forename: Geraldine
authors.initials: G
authors.lastname: Holmes
authors.affiliation: Neuroscience Program, Dominican University, River Forest, IL, United States.
authors.forename: Ashly
authors.initials: A
authors.lastname: Cyriac
authors.affiliation: Neuroscience Program, Dominican University, River Forest, IL, United States. Electronic address: icalinjageman@dom.edu.
authors.forename: Irina E
authors.initials: IE
authors.lastname: Calin-Jageman
authors.affiliation: Neuroscience Program, Dominican University, River Forest, IL, United States. Electronic address: rcalinjageman@dom.edu.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Calin-Jageman
mesh_terms: D000818:Animals; D001048:Aplysia / Q000235:genetics; D059333:Central Nervous System Sensitization / Q000235:genetics*; D004597:Electroshock; D007858:Learning / Q000502:physiology*; D008568:Memory / Q000502:physiology*; D012018:Reflex / Q000502:physiology; D046888:Tissue Array Analysis; D014158:Transcription, Genetic / Q000502:physiology*; D015854:Up-Regulation
keywords: Encoding; Long-term memory; Microarray; Transcription factor