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Research interests
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Evolution through natural selection has shaped nervous systems to generate behaviors. However, there are very few opportunities to study neural circuit evolution where the ancestral and derived forms, as well as the adaptive environment, are all known and accessible. I study the synthesis of neuroethological and developmental principles to understand the evolution of neural adaptation. In my research, I concentrate my efforts into a two-pronged approach that examines the evolution of circuits, molecular mechanisms of behavior, and sensory novelty. Our first prong comprises hypothesis based studies on the role of development in the evolution. Our second research theme is based on discovery: How to animals evolve sensory and behavioral adaptations to extreme environments? Here we focus on exploration of extreme environments, unknown sensory modalities and behavior in the field, where the animals live. This integrative approach links a detailed characterization of the environment with the anatomy and function of neural systems within a phylogenetic context. My research goal is to determine the rules for neural adaptation over generations by manipulating developmental conditions and experiences and and uncovering new sensory modalities and behaviors.

Significant accomplishments:

1. Evolutionary constraints in neuronal coding in the auditory brainstem. I showed that circuits involved in timing of auditory information in the brainstem have a strong evolutionary pressure to maintain certain biophysical characteristics, such as short action potentials. (Neuroanatomy, comparative neurophysiology in vivo and in brain slices).
2. Novel sensory coding in an ancient animal. I described a new sensory organ in the skin of crocodilians. I examined the neuroanatomy, described electrophysiological responses, behavior and determined the paleontological significance of cranial fenestra (behavior, neuroanatomy, neurophysiology and paleontology).
3. Teeth as sensory organs. I lead a research team to describe a new sensory organ in a species of cavefish in Ecuador. These fish have dermal teeth on their dorsal side that create hydrodynamic images from teeth information as adaptations to a high flow environment (behavior, neuroanatomy and neurophysiology)
4. Sensory tradeoffs in cave adaptation. I lead a team that determined that cavefishes don’t necessarily increase hearing sensitivity after losing sight, as previously and widely postulated (comparative anatomy and electrophysiology).
5. Evolution of gaits. I conceived and led a research study that determined that one species of cavefish has a pelvic girdle and is able to walk as a tetrapod (comparative morphology and behavior). I am now collaborating on describing the locomotion of tardigrades.

Selected references

2021 Tanvir Z, Rivera D, Severi KE, Haspel G, Soares D. Evolutionary and homeostatic changes in morphology of visual dendrites of Mauthner cells in Astyanax blind cavefish. J Comp Neurol. 2021 Jun;529(8):1779-1786. doi: 10.1002/cne.25056. Epub 2020 Oct 26. PMID: 33070322; PMCID: PMC8009805.

2020 Yoffe M, Patel K, Palia E, Kolawole S, Streets A, Haspel G, Soares D. Morphological malleability of the lateral line allows for surface fish (Astyanax mexicanus) adaptation to cave environments. J Exp Zool B Mol Dev Evol. 2020 Nov;334(7-8):511-517. doi: 10.1002/jez.b.22953. Epub 2020 May 20. PMID: 32436310.

2020 Gallman K, Fortune E, Rivera D, Soares D. Differences in behavior between surface and cave Astyanax mexicanus may be mediated by changes in catecholamine signaling. J Comp Neurol. 2020 Nov 1;528(16):2639-2653. doi: 10.1002/cne.24923. Epub 2020 May 18. PMID: 32291742; PMCID: PMC7492474.

2020 Fortune ES, Andanar N, Madhav M, Jayakumar RP, Cowan NJ, Bichuette ME, Soares D. Spooky Interaction at a Distance in Cave and Surface Dwelling Electric Fishes. Front Integr Neurosci. 2020 Oct 22;14:561524. doi: 10.3389/fnint.2020.561524. PMID: 33192352; PMCID: PMC7642693.

2020 Emam A, Yoffe M, Cardona H, Soares D. Retinal morphology in Astyanax mexicanus during eye degeneration. J Comp Neurol. 2020 Jun 15;528(9):1523-1534. doi: 10.1002/cne.24835. Epub 2019 Dec 18. PMID: 31811648; PMCID: PMC7153992.

2020 Soares D, Niemiller ML. Extreme Adaptation in Caves. Anat Rec (Hoboken). 2020 Jan;303(1):15-23. doi: 10.1002/ar.24044. Epub 2018 Dec 23. PMID: 30537183.

2019 Privat M, Romano SA, Pietri T, Jouary A, Boulanger-Weill J, Elbaz N, Duchemin A, Soares D, Sumbre G. Sensorimotor Transformations in the Zebrafish Auditory System. Curr Biol. 2019 Dec 2;29(23):4010-4023.e4. doi: 10.1016/j.cub.2019.10.020. Epub 2019 Nov 7. PMID: 31708392; PMCID: PMC6892253.

2019 Capshaw G, Soares D, Carr CE. Bony labyrinth morphometry reveals hidden diversity in lungless salamanders (Family Plethodontidae): Structural correlates of ecology, development, and vision in the inner ear. Evolution. 2019 Oct;73(10):2135-2150. doi: 10.1111/evo.13837. Epub 2019 Sep 2. PMID: 31436320; PMCID: PMC6790150.

2016 Flammang BE, Suvarnaraksha A, Markiewicz J, Soares D. Tetrapod-like pelvic girdle in a walking cavefish. Sci Rep. 2016 Mar 24;6:23711. doi: 10.1038/srep23711. PMID: 27010864; PMCID: PMC4806330.

2013 Niemiller ML, Higgs DM, Soares D. Evidence for hearing loss in amblyopsid cavefishes. Biol Lett. 2013 Mar 27;9(3):20130104. doi: 10.1098/rsbl.2013.0104. PMID: 23536444; PMCID: PMC3645044.

2012 Haspel G, Schwartz A, Streets A, Camacho DE, Soares D. By the teeth of their skin, cavefish find their way. Curr Biol. 2012 Aug 21;22(16):R629-30. doi: 10.1016/j.cub.2012.06.035. PMID: 22917507; PMCID: PMC3427538.

Soares D. Neurology: an ancient sensory organ in crocodilians. Nature. 2002 May 16;417(6886):241-2. doi: 10.1038/417241a. PMID: 12015589.

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