Cocaine supersensitivity and enhanced motivation for reward in mice lacking dopamine D2 autoreceptors

Dopamine (DA) D2 receptors expressed in DA neurons (D2 autoreceptors) exert a negative feedback regulation that reduces DA neuron firing, DA synthesis and DA release. As D2 receptors are mostly expressed in postsynaptic neurons, pharmacological and genetic approaches have been unable to definitively address the in vivo contribution of D2 autoreceptors to DA-mediated behaviors. We found that midbrain DA neurons from mice deficient in D2 autoreceptors (Drd2(loxP/loxP); Dat(+/IRES-cre), referred to as autoDrd2KO mice) lacked DA-mediated somatodendritic synaptic responses and inhibition of DA release. AutoDrd2KO mice displayed elevated DA synthesis and release, hyperlocomotion and supersensitivity to the psychomotor effects of cocaine. The mice also exhibited increased place preference for cocaine and enhanced motivation for food reward. Our results highlight the importance of D2 autoreceptors in the regulation of DA neurotransmission and demonstrate that D2 autoreceptors are important for normal motor function, food-seeking behavior, and sensitivity to the locomotor and rewarding properties of cocaine.     

Exposiciones laborales,dieta y envasado: recomendaciones para reducir los contaminantes medioambientales en la lactancia materna

The pollution of the planet also reaches the breastfeeding ecosystem, one of the most intimate and inviolable that links us as an animal species to the rest of mammals. Nursing mothers may be concerned about whether the quality of their milk will be adequate for their baby and whether environmental pollutants through work, diet, and storing may adversely affect their child. Breast milk is a source of exposure to environmental pollutants, and at the same time it counteracts much of the effects of these exposures. An approach based on the principles of reality and precaution of environmental health to avoid, reduce or eliminate the production and use of harmful chemicals during pregnancy and lactation would improve the human and planetary health for the offspring.     

Chemotherapy-induced nausea and vomiting: pathophysiology and therapeutic principles

Chemotherapy-induced nausea and vomiting (CINV) is a major determinant of quality of life in cancer patients. In addition, the perceptions that oncology professionals have about CINV quite often do not coincide with reality. Antineoplastic agents and their combinations can be categorised according to their emetogenic level, and this categorisation is helpful for classifying the severity of CINV and treating it. All CINV treatment guidelines emphasise the need to administer prophylaxis to patients who receive highly or moderately emetogenic chemotherapy. With the introduction of NK1 receptor antagonists, the control of acute and delayed CINV after highly or moderately emetogenic chemotherapy schedules has improved in the great majority of patients. NK1 receptor antagonists have been demonstrated to improve the control of CINV in all risk subgroups of patients.