In the 1990s, Hornig helped to develop an infection-based model of neurodevelopmental disorders, such as
autism and depression, based on neonatal rat infection with
Borna disease virus. In 2004, Hornig published a controversial paper concluding that, in a highly inbred strain of mice which is unusually susceptible to
autoimmune disease, administration of
thimerosal resulted in the development of autism-like symptoms; specifically, "growth delay; reduced locomotion; exaggerated response to novelty; and densely packed, hyperchromic hippocampal neurons with altered glutamate receptors and transporters". In addition, in an interview with the
Los Angeles Times, Hornig contended that thimerosal may be linked to the recent increases in the incidence of autism. However,
Paul Offit has accused Hornig of overstating her findings, arguing that her study was "a far cry from proving that thimerosal caused autism in children", and Steven Goodman, a member of the IOM panel that rejected a thimerosal-autism link in 2004, shortly before Hornig's study was published, has claimed that this study "in no way substitutes for actual human evidence". Additionally, researchers from the
University of California, Davis were unable to reproduce Hornig's results despite using the same strain of mice and ten times the amount of mercury used in Hornig's study. In 2006, Dan Olmsted reported that Hornig was working on a treatment program in which she would administer
gold salts to these genetically susceptible mice in an attempt to improve their behavior. In 2009, Hornig published another study using mice to examine the mechanism by which
Group A beta-hemolytic streptococcus infections might cause
Tourette's syndrome,
OCD and
tics, in line with the
PANDAS hypothesis. Hornig stated that her findings "illustrate that antibodies alone are sufficient to trigger this behavioral syndrome". ==Personal life==