Abstract
Ethylmercury in thimerosal-preserved childhood vaccines has been suggested to be neurotoxic and to contribute to the etiology of neurodevelopmental disorders, including autism. Immune system function may be an important factor influencing vulnerability of the developing nervous system to thimerosal. This possibility is based in part on a report by Hornig et al. (2004, Mol. Psychiatry 9, 833-845) of neurodevelomental toxicity in SJL/J mice that develop autoantibodies when exposed to organic mercury. The present study reexamined this possibility by injecting neonatal SJL/J mice with thimerosal, with and without combined HiB and DTP vaccines. Injections modeled childhood vaccination schedules, with mice injected on postnatal days 7, 9, 11, and 15 with 14.2, 10.8, 9.2, and 5.6 μg/kg mercury from thimerosal, respectively, or vehicle. Additional groups received vaccine only or a 10 times higher thimerosal + vaccine dose. Low levels of mercury were found in blood, brain, and kidneys 24 h following the last thimerosal injection. Survival, body weight, indices of early development (negative geotaxis, righting) and hippocampal morphology were not affected. Performance was unaffected in behavioral tests selected to assess behavioral domains relevant to core deficits in neurodevelopmental disorders such as autism (i.e., social interaction, sensory gating, anxiety). In an open-field test the majority of behaviors were unaffected by thimerosal injection, although thimerosal-injected female mice showed increased time in the margin of an open field at 4 weeks of age. Considered together the present results do not indicate pervasive developmental neurotoxicity following vaccine-level thimerosal injections in SJL mice, and provide little if any support for the hypothesis that thimerosal exposure contributes to the etiology of neurodevelopmental disorders.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 294-309 |
| Number of pages | 16 |
| Journal | Toxicological Sciences |
| Volume | 101 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2008 |
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Keywords
- Hippocampus
- Locomotor behavior
- Mercury
- SJL mice
- Social behavior
- Stereology
- Thimerosal
ASJC Scopus subject areas
- Toxicology
Cite this
Low-level neonatal thimerosal exposure : Further evaluation of altered neurotoxic potential in SJL mice. / Berman, Robert F; Pessah, Isaac N; Mouton, Peter R.; Mav, Deepak; Harry, Jean.
In: Toxicological Sciences, Vol. 101, No. 2, 02.2008, p. 294-309.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Low-level neonatal thimerosal exposure
T2 - Further evaluation of altered neurotoxic potential in SJL mice
AU - Berman, Robert F
AU - Pessah, Isaac N
AU - Mouton, Peter R.
AU - Mav, Deepak
AU - Harry, Jean
PY - 2008/2
Y1 - 2008/2
N2 - Ethylmercury in thimerosal-preserved childhood vaccines has been suggested to be neurotoxic and to contribute to the etiology of neurodevelopmental disorders, including autism. Immune system function may be an important factor influencing vulnerability of the developing nervous system to thimerosal. This possibility is based in part on a report by Hornig et al. (2004, Mol. Psychiatry 9, 833-845) of neurodevelomental toxicity in SJL/J mice that develop autoantibodies when exposed to organic mercury. The present study reexamined this possibility by injecting neonatal SJL/J mice with thimerosal, with and without combined HiB and DTP vaccines. Injections modeled childhood vaccination schedules, with mice injected on postnatal days 7, 9, 11, and 15 with 14.2, 10.8, 9.2, and 5.6 μg/kg mercury from thimerosal, respectively, or vehicle. Additional groups received vaccine only or a 10 times higher thimerosal + vaccine dose. Low levels of mercury were found in blood, brain, and kidneys 24 h following the last thimerosal injection. Survival, body weight, indices of early development (negative geotaxis, righting) and hippocampal morphology were not affected. Performance was unaffected in behavioral tests selected to assess behavioral domains relevant to core deficits in neurodevelopmental disorders such as autism (i.e., social interaction, sensory gating, anxiety). In an open-field test the majority of behaviors were unaffected by thimerosal injection, although thimerosal-injected female mice showed increased time in the margin of an open field at 4 weeks of age. Considered together the present results do not indicate pervasive developmental neurotoxicity following vaccine-level thimerosal injections in SJL mice, and provide little if any support for the hypothesis that thimerosal exposure contributes to the etiology of neurodevelopmental disorders.
AB - Ethylmercury in thimerosal-preserved childhood vaccines has been suggested to be neurotoxic and to contribute to the etiology of neurodevelopmental disorders, including autism. Immune system function may be an important factor influencing vulnerability of the developing nervous system to thimerosal. This possibility is based in part on a report by Hornig et al. (2004, Mol. Psychiatry 9, 833-845) of neurodevelomental toxicity in SJL/J mice that develop autoantibodies when exposed to organic mercury. The present study reexamined this possibility by injecting neonatal SJL/J mice with thimerosal, with and without combined HiB and DTP vaccines. Injections modeled childhood vaccination schedules, with mice injected on postnatal days 7, 9, 11, and 15 with 14.2, 10.8, 9.2, and 5.6 μg/kg mercury from thimerosal, respectively, or vehicle. Additional groups received vaccine only or a 10 times higher thimerosal + vaccine dose. Low levels of mercury were found in blood, brain, and kidneys 24 h following the last thimerosal injection. Survival, body weight, indices of early development (negative geotaxis, righting) and hippocampal morphology were not affected. Performance was unaffected in behavioral tests selected to assess behavioral domains relevant to core deficits in neurodevelopmental disorders such as autism (i.e., social interaction, sensory gating, anxiety). In an open-field test the majority of behaviors were unaffected by thimerosal injection, although thimerosal-injected female mice showed increased time in the margin of an open field at 4 weeks of age. Considered together the present results do not indicate pervasive developmental neurotoxicity following vaccine-level thimerosal injections in SJL mice, and provide little if any support for the hypothesis that thimerosal exposure contributes to the etiology of neurodevelopmental disorders.
KW - Hippocampus
KW - Locomotor behavior
KW - Mercury
KW - SJL mice
KW - Social behavior
KW - Stereology
KW - Thimerosal
UR - http://www.scopus.com/inward/record.url?scp=38149016287&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=38149016287&partnerID=8YFLogxK
U2 - 10.1093/toxsci/kfm265
DO - 10.1093/toxsci/kfm265
M3 - Article
VL - 101
SP - 294
EP - 309
JO - Toxicological Sciences
JF - Toxicological Sciences
SN - 1096-6080
IS - 2
ER -