Main Menu (Mobile)- Block

Main Menu - Block

janelia7_blocks-janelia7_fake_breadcrumb | block
Lee Tzumin Lab / Publications
general_search_page-panel_pane_1 | views_panes

4 Publications

Showing 1-4 of 4 results
Your Criteria:
    12/19/02 | Memory of sequential experience in the hippocampus during slow wave sleep.
    Lee AK, Wilson MA
    Neuron. 2002 Dec 19;36(6):1183-94

    Rats repeatedly ran through a sequence of spatial receptive fields of hippocampal CA1 place cells in a fixed temporal order. A novel combinatorial decoding method reveals that these neurons repeatedly fired in precisely this order in long sequences involving four or more cells during slow wave sleep (SWS) immediately following, but not preceding, the experience. The SWS sequences occurred intermittently in brief ( approximately 100 ms) bursts, each compressing the behavioral sequence in time by approximately 20-fold. This rapid encoding of sequential experience is consistent with evidence that the hippocampus is crucial for spatial learning in rodents and the formation of long-term memories of events in time in humans.

    View Publication Page
    Cardona Lab
    12/15/02 | A novel invertebrate trophic factor related to invertebrate neurotrophins is involved in planarian body regional survival and asexual reproduction.
    Bueno D, Fernàndez-Rodríguez J, Cardona A, Hernàndez-Hernàndez V, Romero R
    Developmental biology. 2002 Dec 15;252:188-201

    Trophic factors are a heterogeneous group of molecules that promote cell growth and survival. In freshwater planarians, the small secreted protein TCEN49 is linked to the regional maintenance of the planarian central body region. To investigate its function in vivo, we performed loss-of-function and gain-of-function experiments by RNA interference and by the implantation of microbeads soaked in TCEN49, respectively. We show that TCEN49 behaves as a trophic factor involved in central body region neuron survival. In planarian tail regenerates, tcen49 expression inhibition by double-stranded RNA interference causes extensive apoptosis in various cell types, including nerve cells. This phenotype is rescued by the implantation of microbeads soaked in TCEN49 after RNA interference. On the other hand, in organisms committed to asexual reproduction, both tcen49 mRNA and its protein are detected not only in the central body region but also in the posterior region, expanding from cells close to the ventral nerve chords. In some cases, the implantation of microbeads soaked in TCEN49 in the posterior body region drives organisms to reproduce asexually, and the inhibition of tcen49 expression obstructs this process, suggesting a link between the central nervous system, TCEN49, regional induction, and asexual reproduction. Finally, the distribution of TCEN49 cysteine and tyrosine residues also points to a common evolutionary origin for TCEN49 and molluscan neurotrophins.

    View Publication Page
    12/15/02 | High-resolution analysis of ethanol-induced locomotor stimulation in Drosophila.
    Wolf FW, Rodan AR, Tsai LT, Heberlein U
    The Journal of Neuroscience: The Official Journal of the Society for Neuroscience. 2002 Dec 15;22(24):11035-44

    Understanding how ethanol influences behavior is key to deciphering the mechanisms of ethanol action and alcoholism. In mammals, low doses of ethanol stimulate locomotion, whereas high doses depress it. The acute stimulant effect of ethanol has been proposed to be a manifestation of its rewarding effects. In Drosophila, ethanol exposure transiently potentiates locomotor activity in a biphasic dose- and time-dependent manner. An initial short-lived peak of activity corresponds to an olfactory response to ethanol. A second, longer-lasting period of increased activity coincides with rising internal ethanol concentrations; these closely parallel concentrations that stimulate locomotion in mammals. High-resolution analysis of the walking pattern of individual flies revealed that locomotion consists of bouts of activity; bout structure can be quantified by bout frequency, bout length, and the time spent walking at high speeds. Ethanol exposure induces both dramatic and dynamic changes in bout structure. Mutants with increased ethanol sensitivity show distinct changes in ethanol-induced locomotor behavior, as well as genotype-specific changes in activity bout structure. Thus, the overall effect of ethanol on locomotor behavior in Drosophila is caused by changes in discrete quantifiable parameters of walking pattern. The effects of ethanol on locomotion are comparable in flies and mammals, suggesting that Drosophila is a suitable model system to study the underlying mechanisms.

    View Publication Page
    12/01/02 | Drugs, flies, and videotape: the effects of ethanol and cocaine on Drosophila locomotion.
    Rothenfluh A, Heberlein U
    Current Opinion in Neurobiology. 2002 Dec;12(6):639-45

    Drosophila melanogaster has been introduced recently as a model organism in which to study the mechanisms by which drugs of abuse change behavior and by which the nervous system changes upon repeated drug exposure. Surprising similarities between flies and mammals have begun to emerge at the behavioral, neurochemical and molecular levels.

    View Publication Page