Cadmium and exposure to stress increase aggressive behavior

Centro de Assistência Toxicológica (CEATOX), Instituto de Biociências, Universidade Estadual Paulista - UNESP, CEP 18618-000, Distrito de Rubião Júnior, s/n, Botucatu, SP, Brazil.
Environmental toxicology and pharmacology 07/2011; 32(1):40-5. DOI: 10.1016/j.etap.2011.03.005
Source: PubMed


Environmental toxicants and stress influence the health and behavior of people from different parts of the world. In the present study, aggressive behavior was evaluated in rats exposed to cadmium (Cd) for four weeks and subjected to immobilization stress (IS) based on the resident/intruder paradigm. Latency to the first bite (LB), total number of attacks (NA), total duration of attack manifestations (DAM), and a composite aggression score (CAS) were used to assess aggressiveness. Cadmium concentrations in the blood and the brain were determined. We observed that the parameters of aggressiveness were not altered by either Cd or IS when administered separately. However, animals exposed to Cd+IS had increased NA, DAM, and CAS. Cadmium was detected in the blood and the brain after treatment and Cd+IS exposure modified Cd distribution in these tissues. These results suggest that exposure to low levels of Cd associated with stress may lead to increased aggressiveness in rats.

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    • "In fact, Cd is able to cross the blood–brain barrier (BBB) and accumulate in the brain [3] leading to cerebral edema, cellular dysfunction and also the worsening of the synaptic neurotransmission and the antioxidant levels [4] [5] [6]. Some studies have demonstrated that the exposure to Cd can produce impairment of attention, learning and memory as well an increase in aggressive and anxiogenic-like behaviors [7] [8] [9] [10] [11]. In addition, Cd can cause changes in important enzymes of the CNS including acetylcholinesterase (AChE), Na "
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