PUBLICATION
Local Spinal Cord Circuits and Bilateral Mauthner Cell Activity Function Together to Drive Alternative Startle Behaviors
- Authors
- Liu, Y.C., Hale, M.E.
- ID
- ZDB-PUB-170222-19
- Date
- 2017
- Source
- Current biology : CB 27(5): 697-704 (Journal)
- Registered Authors
- Hale, Melina
- Keywords
- Mauthner cell, circuitry, descending input, escape behavior, hindbrain, motoneuron, motor control, preconditioning, sensory input, spinal cord, startle
- MeSH Terms
-
- Animals
- Interneurons/physiology*
- Motor Neurons/physiology*
- Neural Pathways/physiology
- Reflex, Startle/physiology*
- Sensory Receptor Cells/physiology*
- Spinal Cord/physiology*
- Zebrafish/physiology*
- PubMed
- 28216316 Full text @ Curr. Biol.
Citation
Liu, Y.C., Hale, M.E. (2017) Local Spinal Cord Circuits and Bilateral Mauthner Cell Activity Function Together to Drive Alternative Startle Behaviors. Current biology : CB. 27(5):697-704.
Abstract
The reticulospinal Mauthner cells (M-cells) of the startle circuit have been considered to be dedicated to one basic motor output and the C-type startle response in fish. The neural circuit underlying the C-start, a startle behavior in which the fish forms a "C"-shaped body bend has been described in depth in goldfish and zebrafish [1, 2] and is thought to occur in other species [3, 4]. However, previous research has shown that some species can perform a second type of startle called the S-start [5-7]. This startle response, in which the first movement creates an "S"-shaped body bend achieved with regional muscle activity on left and right sides, cannot be explained by M-cell circuit models. Here we use larval zebrafish to examine the S-start circuit. Since S-starts are elicited through tail stimulation [5-7] and ablating M-cells abolishes short-latency tail-elicited startles [8, 9], we hypothesized that M-cell activity was necessary for S-start generation. Our findings show that the M-cells fire simultaneously to generate the S-start. However, simultaneous M-cell spikes generated through direct current injection were not sufficient to generate S-starts. Through recordings of motoneurons, inhibitory interneurons, and sensory neurons, we uncover a mechanism for generating alternative startle behaviors; local sensory inputs drive inhibitory interneuron activity, which inhibits caudal motoneurons and pre-conditions their excitability prior to the arrival of M-cell spikes in the tail. We suggest that this motoneuron hyperpolarization can bias motor output to left or right sides, determining whether the fish performs a C-start or an S-start behavior.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping