Prefrontal cortex dysfunction in hypoxic-ischaemic encephalopathy contributes to executive function impairments in rats: Potential contribution for attention-deficit/hyperactivity disorder.

The world journal of biological psychiatry : the official journal of the World Federation of Societies of Biological Psychiatry

PubMedID: 28105895

Miguel PM, Deniz BF, Deckmann I, Confortim HD, Diaz R, Laureano DP, Silveira PP, Pereira LO. Prefrontal cortex dysfunction in hypoxic-ischaemic encephalopathy contributes to executive function impairments in rats: Potential contribution for attention-deficit/hyperactivity disorder. World J Biol Psychiatry. 2017;1-14.
OBJECTIVES
The attention-deficit/hyperactivity disorder (ADHD) compromises the quality of life of individuals including adaptation to the social environment. ADHD aetiology includes perinatal conditions such as hypoxic-ischaemic events; preclinical studies have demonstrated attentional deficits and impulsive-hyperactive outcomes after neonatal hypoxic and/or ischaemic intervention, but data are missing to understand this relationship. Thus, the aim of this study was to evaluate executive function (EF) and impulsivity, and tissue integrity and dopaminergic function in the prefrontal cortex (PFC) of rats submitted to hypoxia-ischaemia (HI).

METHODS
At postnatal day (PND) 7, male Wistar rats were divided into control (n?=?10) and HI groups (n?=?11) and the HI procedure was conducted. At PND60, the animals were tested in the attentional set-shifting (ASS) task to EF and in the tolerance to delay of reward for assessment of impulsivity. After, morphological analysis and the dopaminergic system were evaluated in the PFC.

RESULTS
Animals subjected to HI had impairments in EF evidenced by a behavioural inflexibility that was correlated to PFC atrophy. Moreover, HI animals presented reduced D2 receptors in the ipsilateral side of ischaemia in the PFC.

CONCLUSIONS
Animals submitted to HI presented impaired EF associated with tissue atrophy and dopaminergic disturbance in the PFC.