Hypothalamic Monoaminergic Pathology in a Neurodevelopmental Rat Model Showing Prenatal 5-Bromo-2'-Deoxyuridine Treatment-Induced Hyperactivity and Hyporeproductivity

Neuropsychobiology. 2020;79(2):161-169. doi: 10.1159/000504552. Epub 2019 Dec 10.

Abstract

Objective: Prenatal treatment of rats with 5-bromo-2'-deoxyuridine (BrdU) is a neurodevelopmental model showing hyperactivity and impaired sexual activity. Human neurodevelopmental disorders, such as autism, exhibit sex-related pathology, but sex-related neurodevelopment has not been fully investigated in this model. We conducted this study to facilitate the understanding of the pathophysiology of neurodevelopmental disorders.

Methods: Pregnant rats received 50 mg/kg BrdU on gestational days 9-15. The tissue content of dopamine (DA), serotonin (5-HT), and their metabolites dihydroxyphenylacetic acid, homovanillic acid, and 5-hydroxyindoleacetic acid were measured in male and female offspring at 3 weeks (juveniles) and 10 weeks (adults) of age.

Results: Prenatally BrdU-treated rats had reduced DA metabolism or DA content in the hypothalamus from the juvenile through the adult period without sex differences, but sex-specific striatal DA abnormalities emerged after maturation. A reduction in 5-HT metabolism was measured in the hypothalamus without sex differences throughout development. Developmental alterations in the striatal 5-HT states were sex-dependent. Temporal changes in DA or 5-HT metabolism were found in the frontal cortex and midbrain.

Conclusion: The sex-specific influence of a genotoxic factor on the development of the DA and 5-HT systems was clarified in the hypothalamus and striatum. The results suggest that the observed sex dependence and region specificity are related to the pathology of social dysfunction in neurodevelopmental disorders.

Keywords: Dopamine; Hyperactivity; Hypothalamus; Serotonin; Sexual activity; Striatum.

MeSH terms

  • Animals
  • Antimetabolites / pharmacology
  • Bromodeoxyuridine / pharmacology
  • Corpus Striatum / metabolism*
  • Disease Models, Animal
  • Dopamine / metabolism*
  • Female
  • Hypothalamus / metabolism*
  • Male
  • Neurodevelopmental Disorders / chemically induced
  • Neurodevelopmental Disorders / metabolism*
  • Pregnancy
  • Prenatal Exposure Delayed Effects / chemically induced
  • Prenatal Exposure Delayed Effects / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Serotonin / metabolism*
  • Sex Characteristics*

Substances

  • Antimetabolites
  • Serotonin
  • Bromodeoxyuridine
  • Dopamine