title: Transcriptional analysis of a whole-body form of long-term habituation in Aplysia californica.
abstract: Habituation is the simplest form of learning, but we know little about the transcriptional mechanisms that encode long-term habituation memory. A key obstacle is that habituation is relatively stimulus-specific and is thus encoded in small sets of neurons, providing poor signal/noise ratios for transcriptional analysis. To overcome this obstacle, we have developed a protocol for producing whole-body long-term habituation of the siphon-withdrawal reflex (SWR) of Aplysia californica. Specifically, we constructed a computer-controlled brushing apparatus to apply low-intensity tactile stimulation over the entire dorsal surface of Aplysia at regular intervals. We found that 3 d of training (10 rounds of stimulation/day; each round = 15 min brushing at a 10-sec ISI; 15-min rest between rounds) produces habituation with several characteristics favorable for mechanistic investigation. First, habituation is widespread, with SWR durations reduced whether the reflex is evoked by tactile stimulation to the head, tail, or the siphon. Second, long-term habituation is sensitive to the pattern of training, occurring only when brushing sessions are spaced out over 3 d rather than massed into a single session. Using a custom-designed microarray and quantitative PCR, we show that long-term habituation produces long-term up-regulation of an apparent Aplysia homolog of cornichon, a protein important for glutamate receptor trafficking. Our training paradigm provides a promising starting point for characterizing the transcriptional mechanisms of long-term habituation memory.
authors.affiliation: Neuroscience Program, Dominican University, River Forest, Illinois, USA.
authors.forename: Geraldine
authors.initials: G
authors.lastname: Holmes
authors.affiliation: Neuroscience Program, Dominican University, River Forest, Illinois, USA.
authors.forename: Samantha
authors.initials: S
authors.lastname: Herdegen
authors.affiliation: Neuroscience Program, Dominican University, River Forest, Illinois, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Schuon
authors.affiliation: Neuroscience Program, Dominican University, River Forest, Illinois, USA.
authors.forename: Ashly
authors.initials: A
authors.lastname: Cyriac
authors.affiliation: Neuroscience Program, Dominican University, River Forest, Illinois, USA.
authors.forename: Jamie
authors.initials: J
authors.lastname: Lass
authors.affiliation: Neuroscience Program, Dominican University, River Forest, Illinois, USA.
authors.forename: Catherine
authors.initials: C
authors.lastname: Conte
authors.affiliation: Neuroscience Program, Dominican University, River Forest, Illinois, USA.
authors.forename: Irina E
authors.identifier: http://orcid.org/0000-0002-2529-4223
authors.initials: IE
authors.lastname: Calin-Jageman
authors.affiliation: Neuroscience Program, Dominican University, River Forest, Illinois, USA rcalinjageman@dom.edu.
authors.forename: Robert J
authors.identifier: http://orcid.org/0000-0002-9837-6529
authors.initials: RJ
authors.lastname: Calin-Jageman
mesh_terms: D000818:Animals; D001048:Aplysia / Q000502:physiology*; D003201:Computers; D004597:Electroshock; D017952:Ganglia, Invertebrate / Q000502:physiology; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006257:Head / Q000502:physiology; D008568:Memory / Q000502:physiology; D046228:Microarray Analysis; D023421:Models, Animal; D010812:Physical Stimulation / Q000295:instrumentation / Q000379:methods; D016133:Polymerase Chain Reaction; D011984:Sensory Receptor Cells / Q000502:physiology; D013623:Tail / Q000502:physiology; D014110:Touch / Q000502:physiology*; D014158:Transcription, Genetic