Studying the function and connectivity of habenular networks in zebrafish brain

Friday, 2017, October 6 - 12:00
Kavli institute for Systems Neuroscience, NTNU, Trondheim, Norway


The habenula (Hb) is a brain region with increasing popularity due to its strong link to addiction, mood disorders and experience dependent fear. We demonstrated that Hb neurons respond to odors and light asymmetrically. Moreover, we showed that Hb neurons exhibit structured spontaneous activity that is spatially and temporally organized. This spontaneous activity resembles neural attractors, which can switch the preferred state of the Hb and regulate the transmission of sensory information to downstream monoaminergic brainstem nuclei. In order to explore the source of Hb spontaneous activity, we investigate the local connectivity within Hb and the global functional inputs to Hb. Our results showed that recurrent excitatory connections within Hb is important for maintaining spatio-temporal organization of Hb activity. Moreover, we observed that functional inputs form zebrafish homologues of hippocampus (Dl) and amygdala (Dm) and sensory inputs from visual and olfactory systems are the major drivers of spontaneous Hb activity. Our results suggested that these limbic and sensory inputs are integrated in Hb in a non-linear fashion and can regulate sensory representations in Hb. We propose that Hb lies in the heart of a brain wide network and act as “a hub” or “a switchboard”, which can regulate or gate the communication of sensory systems and limbic forebrain areas with the monoaminergic brainstem nuclei that control animal behaviors.

Suggested reading:

  1. Jetti SK, Llopis NV, Yaksi E, (2014) Spontaneous activity governs olfactory representations in spa-tially organized habenular microcircuits, Current Biology, 24, 1–6, February 17
  2. Dreosti E, Llopis NV, Yaksi E* and Wilson S*, (2014) Left-right asymmetry is required for the habenulae to respond to both visual and olfactory stimuli, Current Biology, 24, 1–6, February 17. * co-last corresponding authors
  3. Franco LM, Okray Z, Linneweber GA, *Hassan BA, *Yaksi E (2017) Reduced Lateral Inhibition Impairs Olfactory Computations and Behaviors in a Drosophila Model of Fragile X Syndrome. Current Biology, March 30 2017. * co-last authors
  4. Reiten I, Uslu FE, Fore S, Pelgrims R, Ringers C, Verdugo CD, Hoffman M, Lal P, Kawakami K, Pekkan K, Yaksi E*, Jurisch-Yaksi N* (2016) Motile-Cilia-Mediated Flow Improves Sensitivity and Temporal Resolution of Olfactory Computations. Current Biology, Dec 29 2016.* co-last authors
  5. Fore S, Palumbo F, Pelgrims R, Yaksi E (2017), Information processing in the vertebrate habenula. Semin Cell Dev Biol. 2017 Aug 7.