"Evolutionary and homeostatic changes in morphology of visual dendrites" by Zainab Tanvir, Daihana Rivera et al.
 

Evolutionary and homeostatic changes in morphology of visual dendrites of Mauthner cells in Astyanax blind cavefish

Document Type

Article

Publication Date

6-1-2021

Abstract

Mauthner cells are the largest neurons in the hindbrain of teleost fish and most amphibians. Each cell has two major dendrites thought to receive segregated streams of sensory input: the lateral dendrite receives mechanosensory input while the ventral dendrite receives visual input. These inputs, which mediate escape responses to sudden stimuli, may be modulated by the availability of sensory information to the animal. To understand the impact of the absence of visual information on the morphologies of Mauthner cells during developmental and evolutionary time scales, we examined the teleost Astyanax mexicanus. This species of tetra is found in two morphs: a seeing surface fish and a blind cavefish. We compared the structure of Mauthner cells in surface fish raised under daily light conditions, in surface fish raised in constant darkness, and in two independent lineages of cave populations. The length of ventral dendrites of Mauthner cells in dark-raised surface fish larvae were longer and more branched, while in both cave morphs the ventral dendrites were smaller or absent. The absence of visual input in surface fish with normal eye development leads to a homeostatic increase in dendrite size, whereas over evolution, the absence of light led to the loss of eyes and a reduction in dendrite size.

Identifier

85093676525 (Scopus)

Publication Title

Journal of Comparative Neurology

External Full Text Location

https://doi.org/10.1002/cne.25056

e-ISSN

10969861

ISSN

00219967

PubMed ID

33070322

First Page

1779

Last Page

1786

Issue

8

Volume

529

Grant

R15EY027112

Fund Ref

National Eye Institute

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