ZFIN ID: ZDB-PUB-151216-28
In Vivo Ca(2+) Imaging Reveals that Decreased Dendritic Excitability Drives Startle Habituation
Marsden, K.C., Granato, M.
Date: 2015
Source: Cell Reports   13: 1733-40 (Journal)
Registered Authors: Granato, Michael, Marsden, Kurt
Keywords: none
MeSH Terms:
  • Animals
  • Calcium/metabolism*
  • Calcium Signaling/drug effects
  • Dendrites/metabolism*
  • Dizocilpine Maleate/pharmacology
  • Larva/metabolism
  • Neuronal Calcium-Sensor Proteins/metabolism
  • Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors
  • Receptors, N-Methyl-D-Aspartate/metabolism
  • Reflex, Startle/drug effects
  • Strychnine/pharmacology
  • Zebrafish/growth & development
  • Zebrafish/metabolism
PubMed: 26655893 Full text @ Cell Rep.
Exposure to repetitive startling stimuli induces habitation, a simple form of learning. Despite its simplicity, the precise cellular mechanisms by which repeated stimulation converts a robust behavioral response to behavioral indifference are unclear. Here, we use head-restrained zebrafish larvae to monitor subcellular Ca(2+) dynamics in Mauthner neurons, the startle command neurons, during startle habituation in vivo. Using the Ca(2+) reporter GCaMP6s, we find that the amplitude of Ca(2+) signals in the lateral dendrite of the Mauthner neuron determines startle probability and that depression of this dendritic activity rather than downstream inhibition mediates glycine and N-methyl-D-aspartate (NMDA)-receptor-dependent short-term habituation. Combined, our results suggest a model for habituation learning in which increased inhibitory drive from feedforward inhibitory neurons combined with decreased excitatory input from auditory afferents decreases dendritic and Mauthner neuron excitability.