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  • Methylphenidate administrat...
    Miguel, Patrícia Maidana; Deniz, Bruna Ferrary; Confortim, Heloísa Deola; Bronauth, Loise Peres; de Oliveira, Bruna Chaves; Alves, Márcio Bonesso; Silveira, Patrícia Pelufo; Pereira, Lenir Orlandi

    Experimental neurology, 20/May , Letnik: 315
    Journal Article

    Perinatal complications such as birth asphyxia were associated with a higher risk for Attention-Deficit/Hyperactivity Disorder (ADHD) in humans. Data from a rat model of neonatal hypoxia-ischemia (HI) have revealed inattention, impulsive behavior and dopamine (DA) disturbances in the prefrontal cortex (PFC), confirming the face validity and construct validity for ADHD study. However, the predictive validity (similar therapeutic efficacy of the pharmacological treatment available in the clinic) should be considered. Therefore, we aimed to investigate the effects of methylphenidate (MPH) - the treatment of choice for ADHD - on exploratory and attentional flexibility behaviors and DA-related proteins in the PFC of animals submitted to neonatal HI. Male Wistar rats were divided into four groups: control saline (CTS, n = 12), control MPH (CTMPH, n = 12), HI saline (HIS, n = 13) and HIMPH (n = 12). The HI procedure was conducted at postnatal day (PND) 7 and behavioral measures between PND 30–40, followed by protein analysis in the PFC. The MPH administration (2.5 mg/kg, i.p.) occurred 30 min prior each behavioral session and euthanasia for western blot analysis. We observed that the MPH increased the locomotor activity in the open field especially in HI rats. In the attentional-set shifting task, the MPH reversed the HI- induced attentional inflexibility, but impaired the task acquisition in control rats. Neonatal HI resulted in lower DA D2 receptors expression but also decreased DA transporter (responsible for DA reuptake) and increased pTH (phosphorylated-tyrosine hydroxylase) levels in the PFC, probably to compensate the dysfunctional DA transmission. This compensation was higher in the HIMPH group and it could explain the improvement in the attentional flexibility as well as the increased locomotor activity in this group. Taken this data together, we can assume the predictive validity of the HI model for the ADHD study concerning the impact of MPH treatment on attentional parameters. •Methylphenidate increased locomotor activity especially in hypoxic-ischemic rats.•Neonatal hypoxia-ischemia impaired attentional flexibility in adolescent rats.•Methylphenidate reversed attentional inflexibility resulting from hypoxia-ischemia.•Task acquisition learning was impaired by the methylphenidate in control rats.•Hypoxia-ischemia disrupted the dopaminergic system in the prefrontal cortex.