Altered visual processing in a rodent model of Attention-Deficit Hyperactivity Disorder

L. R. Brace, I. Kraev, C. L. Rostron, M. G. Stewart, P. G. Overton, E. J. Dommett*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)
228 Downloads (Pure)

Abstract

A central component of Attention-Deficit Hyperactivity Disorder (ADHD) is increased distractibility, which is linked to the superior colliculus (SC) in a range of species, including humans. Furthermore, there is now mounting evidence of altered collicular functioning in ADHD and it is proposed that a hyper-responsive SC could mediate the main symptoms of ADHD, including distractibility. In the present study we have provided a systematic characterization of the SC in the most commonly used and well-validated animal model of ADHD, the spontaneously hypertensive rat (SHR). We examined collicular-dependent orienting behavior, local field potential (LFP) and multiunit responses to visual stimuli in the anesthetized rat and morphological measures in the SHR in comparison to the Wistar Kyoto (WKY) and Wistar (WIS). We found that SHRs remain responsive to a repeated visual stimulus for more presentations than control strains and have a longer response duration. In addition, LFP and multiunit activity within the visually responsive superficial layers of the SC showed the SHR to have a hyper-responsive SC relative to control strains, which could not be explained by altered functioning of the retinocollicular pathway. Finally, examination of collicular volume, neuron and glia densities and glia:neuron ratio revealed that the SHR had a reduced ratio relative to the WKY which could explain the increased responsiveness. In conclusion, this study demonstrates strain-specific changes in the functioning and structure of the SC in the SHR, providing convergent evidence that the SC might be dysfunctional in ADHD.

Original languageEnglish
Pages (from-to)364-377
Number of pages14
JournalNeuroscience
Volume303
Early online date9 Jul 2015
DOIs
Publication statusPublished - 10 Sept 2015

Keywords

  • Distractibility
  • Orienting
  • Spontaneously hypertensive rat
  • Superior colliculus

Fingerprint

Dive into the research topics of 'Altered visual processing in a rodent model of Attention-Deficit Hyperactivity Disorder'. Together they form a unique fingerprint.

Cite this