Thrsp Gene and the ADHD Predominantly Inattentive Presentation

Abstract

There are three presentations of attention-deficit/hyperactivity disorder (ADHD): the predominantly inattention (ADHD-PI), predominantly hyperactive–impulsive (ADHD-HI), and combined (ADHD-C) presentations of ADHD. These may represent distinct childhood-onset neurobehavioral disorders with separate etiologies. ADHD diagnoses are behaviorally based, so investigations into potential etiologies should be founded on behavior. Animal models of ADHD demonstrate face, predictive, and construct validity when they accurately reproduce elements of the symptoms, etiology, biochemistry, and disorder treatment. Spontaneously hypertensive rats (SHR/NCrl) fulfill many validation criteria and compare well with clinical cases of ADHD-C. Compounding the difficulty of selecting an ideal model to study specific presentations of ADHD is a simple fact that our knowledge regarding ADHD neurobiology is insufficient. Accordingly, the current review has explored a potential animal model for a specific presentation, ADHD-PI, with acceptable face, predictive, and construct validity. The Thrsp gene could be a biomarker for ADHD-PI presentation, and THRSP OE mice could represent an animal model for studying this distinct ADHD presentation.

Adult ADHD: It is Old and New at the same time. What is it?

“…Moreover, the thyroid hormones regulated by the HPA axis were dysregulated in ADHD [56,57], particularly those with hypothyroidism and generalized resistance to thyroid hormone (GRTH). Hypothyroidism during fetal and postnatal periods causes developmental delays, while in adulthood, it induces neuronal network abnormalities, resulting in profound behavioral and neurological defects, including inattention and memory impairment [58][59][60][61][62][63]. Also, it should be noted that thyroid hormone and dopamine share the same basic unit, tyrosine [64], so it is conceivable that abnormalities in thyroid hormone levels and function may affect dopamine function; for instance, hypothyroidism often leads to the loss of DA neurons [65].…”

“…On average, the protein-coding regions of human and mouse genomes are 85% identical, making mouse genetic research valuable for understanding human disorders. In addition, the use of genetically modified mouse models (transgenics) has become useful in neuroscience research, particularly in understanding ADHD pathology [85], and their subtypes: predominantly inattentive (ADHD-PI) [61][62][63]86], hyperactive-impulsive (ADHD-HI) [87], and combined (ADHD-C) [88,89]. This methodology contributes to interpreting the genotype-phenotype associations in ADHD.…”