title: Left-right asymmetry is required for the habenulae to respond to both visual and olfactory stimuli.
abstract: Left-right asymmetries are most likely a universal feature of bilaterian nervous systems and may serve to increase neural capacity by specializing equivalent structures on left and right sides for distinct roles. However, little is known about how asymmetries are encoded within vertebrate neural circuits and how lateralization influences processing of information in the brain. Consequently, it remains unclear the extent to which lateralization of the nervous system is important for normal cognitive and other brain functions and whether defects in lateralization contribute to neurological deficits. Here we show that sensory responses to light and odor are lateralized in larval zebrafish habenulae and that loss of brain asymmetry leads to concomitant loss of responsiveness to either visual or olfactory stimuli. We find that in wild-type zebrafish, most habenular neurons responding to light are present on the left, whereas neurons responding to odor are more frequent on the right. Manipulations that reverse the direction of brain asymmetry reverse the functional properties of habenular neurons, whereas manipulations that generate either double-left- or double-right-sided brains lead to loss of habenular responsiveness to either odor or light, respectively. Our results indicate that loss of brain lateralization has significant consequences upon sensory processing and circuit function.
authors: Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK; NERF, Kapeldreef 75, 3001 Leuven, Belgium. Electronic address: e.dreosti@ucl.ac.uk.
authors: Elena
authors: E
authors: Dreosti
authors: NERF, Kapeldreef 75, 3001 Leuven, Belgium; KU Leuven, Kapeldreef 75, 3001 Leuven, Belgium.
authors: Nuria
authors: N
authors: Vendrell Llopis
authors: Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK; Department of Cell and Molecular Biology, Medical Faculty Mannheim, University of Heidelberg, Ludolf-Krehl-Strasse 13-17, 68167 Mannheim, Germany.
authors: Matthias
authors: M
authors: Carl
authors: NERF, Kapeldreef 75, 3001 Leuven, Belgium; KU Leuven, Kapeldreef 75, 3001 Leuven, Belgium; VIB, Kapeldreef 75, 3001 Leuven, Belgium. Electronic address: emre.yaksi@nerf.be.
authors: Emre
authors: E
authors: Yaksi
authors: Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK. Electronic address: s.wilson@ucl.ac.uk.
authors: Stephen W
authors: SW
authors: Wilson
mesh_terms: D000818:Animals; D019521:Body Patterning; D019262:Habenula / Q000502:physiology*; D009830:Olfactory Bulb / Q000502:physiology*; D010775:Photic Stimulation; D055697:Taste Perception; D014796:Visual Perception; D015027:Zebrafish / Q000502:physiology*