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
Recommended Citation
Tanvir, Zainab; Rivera, Daihana; Severi, Kristen E.; Haspel, Gal; and Soares, Daphne, "Evolutionary and homeostatic changes in morphology of visual dendrites of Mauthner cells in Astyanax blind cavefish" (2021). Faculty Publications. 4053.
https://digitalcommons.njit.edu/fac_pubs/4053