|ZFIN ID: ZDB-PUB-151216-28|
In Vivo Ca(2+) Imaging Reveals that Decreased Dendritic Excitability Drives Startle Habituation
Marsden, K.C., Granato, M.
|Source:||Cell Reports 13: 1733-40 (Journal)|
|Registered Authors:||Granato, Michael, Marsden, Kurt|
|PubMed:||26655893 Full text @ Cell Rep.|
Marsden, K.C., Granato, M. (2015) In Vivo Ca(2+) Imaging Reveals that Decreased Dendritic Excitability Drives Startle Habituation. Cell Reports. 13:1733-40.
ABSTRACTExposure 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.