Carbon Monoxide Headquarters
CO and Risk

Carbon Monoxide Poisoning

Special Groups at Risk:

Table 2. Prenatal CO Exposure - Animal Studies - Structural Changes in Brain, etc.:

Species Carbon Monoxide Exposure Effects
chicken very high level CO, few hours, 7 days hemorrhage in forebrain area; reduced branching of dendritic tree and reduced nuclear size of the
paleostriatum primitivum seen in embryos just before hatching
rat high level CO, 3 hours, 1 day damage to the germinal matrix overlying the developing caudate nucleus, consisting of hemorrhage infarcts
with necrosis and cavities with cellular debris
rat moderate-high level CO, throughout gestation cerebellar wts. decreased with increasing CO conc.; Norepinephrine and serotonin conc. in pons medulla decreased directly
with increasing CO 3 weeks after birth. Norepinephrine also increased with CO conc. in neocortex
rat moderate level CO cerebellar norepinephrine conc. & content increased during 2nd-6th postnatal week
rat moderate-high level CO, conception through 10 days after birth cerebellar wt. & content of gamma-aminobutyric acid (GABA) decreased post-birth. Total cerebellar high-afinity tritiated GABA uptake decreased post-birth in rats at high CO
rat moderate-high level CO, throughout gestation cerebellar wt. & neurochemical markers of GABAergic neurons reduced. Numbers of fissures and degenerating Purkinje
and granule cells in the cerebral cortex decreased. DNA content of the neostriatum increased as the result of high CO level,
as well as dopamine content. Norepinephrine and serotonin decreased slightly in the pons medulla after birth
rat moderate-high level CO, latter half of gestation hippocampal ornithine decarboxylase activity doubled after 4 hours
rat moderate level CO, throughout gestation pathological signs suggestive of Wallerian degeneration in the sciatic nerve, seen in middle-aged rats
rat lower to moderate level CO, throughout gestation inactivation kinetics of transient sodium current in sciatic nerve slowed; negative shift in the sodium equilibrium potential
rat lower to moderate level CO, throughout gestation splenic macrophage phagocytosis of Candida albicans and superoxide radical release decreased in neonates
cat high level CO, 1 - 2.5 hours the most vulnerable areas were the cerebral white matter and brain stem, followed by the basal ganglia and thalamus, then the cerebral cortex
rhesus monkey high level CO, near term, 1-3 hours Of 9 newborn, 4 were normal, 1 showed moderate dysfunction, and 4 severe damage. One newborn with hypotonia, lethargy, a poor suck response, and apneic spells. Autopsy revealed hemorrhagic necrosis affecting the globus pallidus and putamen bilaterally. Four severely damaged newborn had increased intracranial pressure with splitting of the cranial sutures and prominent retinal hemorrhages. Neurologically, they displayed nystagmus, opisthotonus, and intermittent extensor spasms. These had hemorrhagic necrosis of the cerebral cortex, the basal ganglia, and the thalamus of both hemispheres.

Note: For more detailed information, contact the webmaster (E-mail =, or consult the book Carbon Monoxide, 1996, by David G. Penney, Ph.D.

...... last changed 07/02/02

Back to CO at Risk Index