A comparative study of the effects of ABT-418 and methylphenidate on spatial memory in an animal model of ADHD.

Impaired learning performance in scholastic settings is a characteristic of attention deficit hyperactivity disorder (ADHD). Our present study compares the effect of a nicotinic acetylcholine receptor (nAChR) agonist, ABT-418, and methylphenidate (MPH) on spatial memory in spontaneously hypertensive rats (SHRs), an animal model of ADHD. Neither chronic administration of ABT-418 nor MPH affected the learning performance during training in the Morris water maze. However, both compounds significantly improved memory. SHRs treated with a combination of the compounds did not perform better than either drug alone. Furthermore, the cortical α4 and β2 nAChR subunits and the hippocampal α4 subunit expression were significantly enhanced by ABT-418 treatments. Collectively, these results suggest that ABT-418 effectively improved spatial memory in an animal model of ADHD, providing a theoretical foundation for the use of a nAChR agonist in ADHD treatment.