RESUMEN

Pediculosis is a parasitic disease that is considered a serious global public health problem. It is caused by the ectoparasite that is popularly known as lice, mainly affecting children in early childhood. The most commonly used treatment to combat this parasitosis is the macrocyclic lactone ivermectin (IVM). However, the use of IVM is contraindicated in children who are younger than 5 years old or who weigh <15 kg because some types of drugs that are used during certain periods of brain maturation can lead to behavioral disorders. The present study evaluated the effects of IVM treatment during the prepubertal and pubertal period on sexual behavior in adulthood in male rats. Genital grooming, preputial separation, sexual behavior, sexual motivation, relative organ weight, the gonadosomatic index, and histopathology were evaluated. Oral dose of 0.2 mg/kg (therapeutic dose) of a commercial IVM formulation was administered. IVM affected genital grooming but did not influence preputial separation in prepubertal rats. Prepubertal IVM administration did not impair sexual behavior in adult rats, with the exception of the time of residence with female rats in the sexual motivation test. It did not affect relative organ weights, with the exception of the relative weight of the full seminal vesicle. It did not alter the gonadosomatic index, and no histopathological alterations were observed in different organs. These results indicate that administration of a therapeutic dose of IVM during the prepubertal and pubertal period does not alter parameters of sexual development or sexual behavior in adult male rats.

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RESUMEN

Ivermectin (IVM) is a macrocyclic lactone used for the treatment of parasitic infections and widely used in veterinary medicine as endectocide. In mammals, evidence indicates that IVM interacts with γ-aminobutyric acid (GABA)-mediated chloride channels. GABAergic system is involved in the manifestation of sexual behavior. We previously found that IVM at therapeutic doses did not alter sexual behavior in male rats, but at a higher dose, the appetitive phase of sexual behavior was impaired. Thus, we investigated whether the reduction of sexual behavior that was previously observed was a consequence of motor or motivational deficits that are induced by IVM. Data showed significant decrease in striatal dopaminergic system activity and lower testosterone levels but no effects on sexual motivation or penile erection. These findings suggest IVM may activate the GABAergic system and reduce testosterone levels, resulting in a reduction of motor coordination as consequence of the inhibition of striatal dopamine release.

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RESUMEN

Adolescence is one of the critical periods of development and has great importance to health for an individual as an adult. Stressors or traumatic events during this period are associated with several psychiatric disorders as related to anxiety or depression and cognitive impairments, but whether negative experiences continue to hinder individuals as they age is not as well understood. We determined how stress during adolescence affects behavior and neurochemistry in adulthood. Using an unpredictable paradigm (2 stressors per day for 10days) in Balb/c mice, behavioral, hormonal, and neurochemical changes were identified 20days after the cessation of treatment. Adolescent stress increased motor activity, emotional arousal and vigilance, together with a reduction in anxiety, and also affected recognition memory. Furthermore, decreased serotonergic activity on hippocampus, hypothalamus and cortex, decreased noradrenergic activity on hippocampus and hypothalamus, and increased the turnover of dopamine in cortex. These data suggest behavioral phenotypes associated with emotional arousal, but not depression, emerge after cessation of stress and remain in adulthood. Social-environmental stress can induce marked and long-lasting changes in HPA resulting from monoaminergic neurotransmission, mainly 5-HT activity.

Asunto(s)

RESUMEN

Ivermectin (IVM) is a macrocyclic lactone used for the treatment of parasitic infections and widely used in veterinary medicine as endectocide. In mammals, evidence indicates that IVM interacts with ?-aminobutyric acid (GABA)-mediated chloride channels. GABAergic system is involved in the manifestation of sexual behavior. We previously found that IVM at therapeutic doses did not alter sexual behavior in male rats, but at a higher dose, the appetitive phase of sexual behavior was impaired. Thus, we investigated whether the reduction of sexual behavior that was previously observed was a consequence of motor or motivational deficits that are induced by IVM. Data showed significant decrease in striatal dopaminergic system activity and lower testosterone levels but no effects on sexual motivation or penile erection. These findings suggest IVM may activate the GABAergic system and reduce testosterone levels, resulting in a reduction of motor coordination as consequence of the inhibition of striatal dopamine release.