Differences in behavior between surface and cave Astyanax mexicanus may be mediated by changes in catecholamine signaling

Kathryn Gallman, Eric Fortune, Daihana Rivera, Daphne Soares

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Astyanax mexicanus is a teleost fish that is in the process of allopatric speciation. Ancestral Astyanax are found in surface rivers and derived blind forms are found in cave systems. Adaptation to life in nutrient poor caves without predation includes the evolution of enhanced food seeking behaviors and loss of defensive responses. These behavioral adaptations may be mediated by changes in catecholaminergic control systems in the brain. We examined the distribution of tyrosine hydroxylase, a conserved precursor for the synthesis of the catecholamines dopamine and noradrenaline, in the brains of surface and cave Astyanax using immunohistochemistry. We found differences in tyrosine hydroxylase staining in regions that are associated with nonvisual sensory perception, motor control, endocrine release, and attention. These differences included significant increases in the diameters of tyrosine hydroxylase immunoreactive soma in cave Astyanax in the olfactory bulb, basal telencephalon, preoptic nuclei, ventral thalamus, posterior tuberculum, and locus coeruleus. These increases in modulation by dopamine and noradrenaline likely indicate changes in behavioral control that underlie adaptations to the cave environment.

Original languageEnglish (US)
Pages (from-to)2639-2653
Number of pages15
JournalJournal of Comparative Neurology
Issue number16
StatePublished - Nov 1 2020

All Science Journal Classification (ASJC) codes

  • General Neuroscience


  • adaptation
  • catecholamines
  • dopamine
  • evolution
  • noradrenaline
  • teleost fish
  • tyrosine hydroxylase


Dive into the research topics of 'Differences in behavior between surface and cave Astyanax mexicanus may be mediated by changes in catecholamine signaling'. Together they form a unique fingerprint.

Cite this