Decrease in learning

Degeneration of these same neurons is also associated with an age-dependent decrease in learning and memory ability. Infusion of NGF and NT-4/5 to aged rats appears to improve their spatial memory ability. Further studies in rodents have shown that physical exercise increased BDNF expression, which may explain why exercise is often a predictor of high mental function during ageing. 

Lead Anaemia, gastrointestinal disturbances, peripheral neuropathy, encephalopathy, decrease in learning ability in children. 

CMV, a virus of the herpes family, isa common viral infection. Healthy individuals may beoome infected yet have no symptoms. However, immunocompromised patients (such as those with HIV or cancer) may have the infection. Symptoms include malaise, fever, pneumonia, and super infection. Infants may acquire the virus from the mother while in the uterus, resulting in learning disabilities and mental retardation. CM V can infect the eye, causing retinitis. Symptoms of CMV retinitis are blurred vision and decreased visual acuity. Visual impairment is irreversible and can lead to blindness if untreated. 

The involvement of the cerebellum in the psychoactive effects of marijuana and in changes in rCMR is consistent with the view that THC interacts with the high concentration of CB1 receptors in this brain area. Decreases in the cerebellar rCMR in habitual marijuana users may reflect the effects of chronic exposure to the drug. Functions known to be associated with the cerebellum, such as motor coordination, proprioception, and learning, are adversely affected both during acute marijuana intoxication and in habitual users. 

Chronic opiate treatment results in complex adaptations in opioid receptor signaling. Much has been learned from studies on mechanisms of tolerance to the analgesic effects of opiates. This is a major clinical problem, as it means that ever-escalating doses are required for the treatment of chronic pain. The classic view was that tolerance reflects a decrease in functional opioid receptors via desensitization and internalization. Desensitization occurs when receptors are uncoupled from G proteins as a result of phosphorylation by G-protein-coupled receptor... 

In this interview Katy shares her view that chemical exposures can lead to an inability to tolerate stress, to loss of mental functioning, to fear and to violence. Since I met with her, two studies have been published that validate her remarks. One, a University of Wis-consin-Madison study published in the journal Toxicology and Industrial Health, January-March 1999, found that the pesticide-fertilizer mixtures commonly found in groundwater can affect patterns of aggression and the ability to learn, and causes hormone disruptions that increase sensitivity to stimuli, irritability and immune dysfunction. A University of Arizona study published by Environmental Health Perspectives in June 1998 showed a decrease in mental ability and an increase in aggressive behavior among children exposed to pesticides. 

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