biostudies-literatureMarsden KCNEI NIH HHSNIMH NIH HHSNINDS NIH HHS1733-40https://www.ebi.ac.uk/biostudies/studies/S-EPMC4680997biostudies-literatureUnknown13(9)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.Cell reportsIn Vivo Ca(2+) Imaging Reveals that Decreased Dendritic Excitability Drives Startle Habituation.PMC4680997R01 MH075691R01 MH092257R01 EY024861F32-NS-077815MH092257MH103545EY024861R03 MH102680F32 NS077815R21 MH103545Marsden KCGranato MfalseIn Vivo Ca(2+) Imaging Reveals that Decreased Dendritic Excitability Drives Startle Habituation.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.2015-01-01T00:00:00Z2015 Dec2025-04-19T08:22:28.734Z2019-03-27T02:05:15ZS-EPMC46809972665589310.1016/j.celrep.2015.10.060