Neurological system

Although there are no data from human studies that indicate that hepatic effects occur in humans exposed to heptachlor, the animal studies indicate that the liver is a target organ for this chemical and is more sensitive to low doses than the neurological system. Decreased glycogen, increased cholesterol, GOT, and AP enzyme levels, and increased liver weight were reported in mice fed heptachlor at 0.5 mg/kg/day. In contrast, neurological effects such as convulsions were observed in a cow fed 2.5 mg/kg/day heptachlor daily for 15 days (Buck et al. 1959). Increased liver enzymes could indicate exposure to heptachlor, but this would not be a marker specific to this chemical. Refer to Section 2.2 for a detailed discussion of the effects caused by heptachlor and heptachlor epoxide. 

The symptoms of ciguatera poisoning are complex, involving the digestive, cardiovascular, and neurological systems (see below) the symptoms can occur in various combinations (11). 

Neurotoxicity. No histopathological effects on organs and tissues of the neurological systems of animals were found in subchronic and chronic oral studies, but signs of central nervous system toxicity were reported in inhalation, oral, and dermal studies. A battery of tests for neurotoxicity would provide further information of the neurotoxicity in animals, which then might be related to possible neurotoxic effects in humans. 

Neurological system nystagmus (involuntary, rapid eye movement) vertigo (a false sensation of motion or spinning) dizziness ataxia (poor muscle coordination) weakness and sedation. 

Children are the most susceptible population to contaminants indoors, especially in house dust because (i) their organs and neurological system are rapidly developing, (ii) their intake is greater relative to body size and weight, (iii) their activities on and proximity to the surfaces enhance their potential contact with toxic substances (IPCS, 1986). 

Although motor effects have been described in rats dosed with 2,3,7,8-TCDD, in most studies, the neurological system was not specifically examined therefore the issue of whether CDDs have a direct effect on the nervous system of animals has not been conclusively resolved. 

Some human studies have reported effects on the central and peripheral nervous systems shortly after exposure to high levels of 2,3,7,8-TCDD (Filippini et al. 1981 Moses et al. 1984 Pazderova-Vejlupkova et al. 1981 Pocchiari et al. 1979 Suskind 1977). However, follow-up studies did not find neurological effects years after exposure termination (Barbieri et al. 1988), suggesting that the effects may be transient. No human studies examined the effect of 2,3,7,8-TCDD on the developing neurologic system. 

Neurological System Assistance with managing disaster-related stress and the provision of safe environments against violence and abuse, especially for those with brain injury and mental deficits... 

The form with which most of the public is familiar is foodborne botulism. There are approximately 30 cases of foodborne botulism reported in the United States each year, most of which are related to home processing of foods. The botulinum toxin produced by C. botulinum is actually a group of distinct toxins with similar paralytic effects on the neurologic system. Botulinum toxin is the most poisonous substance known to mankind less than one microgram is a fatal dose for an adult (Arnon et al., 2001). 

Drugs acting on the neurological system and behavior modification... 

DRUGS ACTING ON THE NEUROLOGICAL SYSTEM AND BEHAVIOR MODIFICATION 147... 

Symptoms of toxicity are related to the cardiovascular, gastrointestinal, and neurological systems. These include bradycardia, ventricular tachycardia, nausea, and vomiting. Paresthesias of the extremities and generalized weakness have been reported. Rarely, seizures may occur in humans. This symptom is more commonly seen in animal models. 

Neuropharmacology The study of how medication interacts with the neurologic system... 

---