Ontogeny and innervation patterns of dopaminergic, noradrenergic, and serotonergic neurons in larval zebrafish

David L. McLean; Joseph R. Fetcho

doi:10.1002/cne.20280

Ontogeny and innervation patterns of dopaminergic, noradrenergic, and serotonergic neurons in larval zebrafish

The Journal of Comparative Neurology ◽

10.1002/cne.20280 ◽

2004 ◽

Vol 480 (1) ◽

pp. 38-56 ◽

Cited By ~ 163

Author(s):

David L. McLean ◽

Joseph R. Fetcho

Keyword(s):

Serotonergic Neurons ◽

Larval Zebrafish ◽

Innervation Patterns

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Activation and inhibition of tph2 serotonergic neurons operate in tandem to influence larval zebrafish preference for light over darkness

Scientific Reports ◽

10.1038/srep20788 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 19

Author(s):

Ruey-Kuang Cheng ◽

Seetha Krishnan ◽

Suresh Jesuthasan

Keyword(s):

Serotonergic Neurons ◽

Larval Zebrafish

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Central and peripheral innervation patterns of defined axial motor units in larval zebrafish

10.1101/559062 ◽

2019 ◽

Author(s):

Saul Bello-Rojas ◽

Ana E. Istrate ◽

Sandeep Kishore ◽

David L. McLean

Keyword(s):

Motor Neurons ◽

Muscle Fibers ◽

Motor Units ◽

Spinal Motor Neurons ◽

Larval Zebrafish ◽

Spinal Motor ◽

Axon Collaterals ◽

Peripheral Innervation ◽

Innervation Patterns ◽

Fast Twitch

AbstractSpinal motor neurons and the peripheral muscle fibers they innervate form discrete motor units that execute movements of varying force and speed. Subsets of spinal motor neurons also exhibit axon collaterals that influence motor output centrally. Here, we have used in vivo imaging to anatomically characterize the central and peripheral innervation patterns of axial motor units in larval zebrafish. Using early born ‘primary’ motor neurons and their division of epaxial and hypaxial muscle into four distinct quadrants as a reference, we define three distinct types of later born ‘secondary’ motor units. The largest are ‘m-type’ units, which innervate deeper fast-twitch muscle fibers via medial nerves. Next in size are ‘ms-type’ secondaries, which innervate superficial fast-twitch and slow fibers via medial and septal nerves, followed by ‘s-type’ units, which exclusively innervate superficial slow muscle fibers via septal nerves. All types of secondaries innervate up to four axial quadrants. Central axon collaterals are found in subsets of primaries based on soma position and predominantly in secondary fast-twitch units (m, ms) with increasing likelihood based on number of quadrants innervated. Collaterals are labeled by synaptophysin-tagged fluorescent proteins, but not PSD95, consistent with their output function. Also, PSD95 dendrite labeling reveals that larger motor units receive more excitatory synaptic input. Collaterals are largely restricted to the neuropil, however perisomatic connections are observed between motor units. These observations suggest that recurrent interactions are dominated by motor neurons recruited during stronger movements and set the stage for functional investigations of recurrent motor circuitry in larval zebrafish.

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