Behavioral deficits induced by lead exposure are accompanied by serotonergic and cholinergic alterations in the prefrontal cortex
The effects of long-term lead (Pb) exposure producing a blood Pb concentration of lower than 20 μg/dL, i.e. below that associated with overt neurological deficits in occupationally exposed individuals, was studied in adult rats. In order to assess gender differences, we performed parallel behavioral experiments in male and female rats. Exposure to Pb acetate (50 ppm in drinking water) for 6 months induced motor and cognitive alterations, however these effects were gender- and task-dependent. Chronic lead exposure impaired spatial learning assessed in the Morris water maze test (MWM) in both genders, whereas it only induced hyperactivity in the open field and impaired motor coordination in t…
Venlafaxine prevents morphine antinociceptive tolerance: The role of neuroinflammation and the l-arginine-nitric oxide pathway.
Abstract Opioid-induced neuroinflammation and the nitric oxide (NO) signal-transduction pathway are involved in the development of opioid analgesic tolerance. The antidepressant venlafaxine (VLF) modulates NO in nervous tissues, and so we investigated its effect on induced tolerance to morphine, neuroinflammation, and oxidative stress in mice. Tolerance to the analgesic effects of morphine were induced by injecting mice with morphine (50 mg/kg) once a day for three consecutive days; the effect of co-administration of VLF (5 or 40 mg/kg) with morphine was similarly tested in a separate group. To determine if the NO precursor l -arginine hydrochloride ( l -arg) or NO are involved in the effec…
Gender-dependent behavioural impairment and brain metabolites in young adult rats after short term exposure to lead acetate
We investigated the behavioural effects of short-term lead (Pb) exposure in adult rats producing blood Pb concentration (<10. μg/dL) below those associated with neurological impairment in occupationally exposed individuals. In order to assess gender differences, we performed parallel behavioural experiments in male and female rats. Exposure to Pb acetate (50. mg/L in drinking water) for 30-45 days induced behavioural alterations consisting in hyperactivity in a novel environment and impairment of spatial memory. These effects were observed only in male rats. Object recognition, motor coordination were unaffected by Pb exposure. Magnetic resonance spectroscopy allows . in vivo assessment of …
Cognitive impairment associated with chronic lead exposure in adults
Abstract Lead (Pb) exposure interferes with many biochemical events present in cells of the central nervous system (neurons and astrocytes) and it can produce a wide spectrum of alterations including cognitive impairment. The review summarizes the main cognitive alterations induced by chronic Pb exposure in adults/older individuals. We have focused on the current state of knowledge concerning the most vulnerable brain areas to Pb exposure that accompanied by the long-lasting neurological effects of Pb in cognitive functions. We tried to correlate the cognitive deficits induced by Pb exposure in animal models during adulthood with those reported in humans. The great interest in whether expos…