Intraindividual variability (IIV) in an animal model of ADHD - the Spontaneously Hypertensive Rat
<p>Abstract</p> <p>Attention-deficit/hyperactivity disorder (ADHD) is characterized by numerous behaviors including inattention, hyperactivity and impulsiveness. ADHD-affected individuals also have high intra-individual variability (IIV) in reaction time. The genetic control of IIV...
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| Format: | Article |
| Language: | English |
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BMC
2010-10-01
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| Series: | Behavioral and Brain Functions |
| Online Access: | http://www.behavioralandbrainfunctions.com/content/6/1/56 |
| _version_ | 1818964262165413888 |
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| author | Sagvolden Terje Perry Guy ML Faraone Stephen V |
| author_facet | Sagvolden Terje Perry Guy ML Faraone Stephen V |
| author_sort | Sagvolden Terje |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Attention-deficit/hyperactivity disorder (ADHD) is characterized by numerous behaviors including inattention, hyperactivity and impulsiveness. ADHD-affected individuals also have high intra-individual variability (IIV) in reaction time. The genetic control of IIV is not well understood. The single study of the genetics of this phenomenon in humans detected only marginal associations between genotypes at two candidate genes for ADHD and variability in response time. The Spontaneously Hypertensive Rat (SHR/NCrl) is an animal model of ADHD, expressing high activity, inattention and impulsive behavior during operant and task tests. The SHR might be useful for identifying genes for variability, but it is not known whether it also expresses high IIV, as is symptomatic of ADHD. We therefore conducted an investigation of IIV in the SHR. We used 16 SHR/NCrl rats and 15 Wistar-Kyoto (WKY/Nico) controls applying a reinforcement schedule used in the validation of the SHR as an animal model of ADHD. We represented IIV as the average absolute deviation of individual behavior within the five 18-min segments of each experimental session from the average behavioral trait value within that session ('individual phenotypic dispersion', <it>PD<sub>i</sub></it>). <it>PD<sub>i </sub></it>for hyperactivity, impulsiveness and inattention in the SHR and WKY rats was analyzed using nonparametric ranking by experimental session. SHR/NCrl rats had higher <it>PD<sub>i </sub></it>than WKY/Nico controls for impulsiveness and inattention. There was a significant upward trend for <it>PD<sub>i </sub></it>over experimental segments within sessions for attention in SHR rats, but not in WKY. <it>PD<sub>i </sub></it>for hyperactivity was correlated with <it>PD<sub>i </sub></it>for impulsiveness and we therefore excluded observations associated with short IRTs (< 0.67s); dispersion in hyperactivity outside this interval was also significantly higher in SHR rats than in WKY rats. Some studies indicate the sharing of symptoms of hyperactivity and impulsiveness in SHR and ADHD-affected humans; high IIV in operant behavioral metrics suggests that the SHR may be useful in elucidating the genetic basis for IIV in humans.</p> |
| first_indexed | 2024-12-20T12:58:19Z |
| format | Article |
| id | doaj.art-4d1be12329c34362b16827cc5920227d |
| institution | Directory Open Access Journal |
| issn | 1744-9081 |
| language | English |
| last_indexed | 2024-12-20T12:58:19Z |
| publishDate | 2010-10-01 |
| publisher | BMC |
| record_format | Article |
| series | Behavioral and Brain Functions |
| spelling | doaj.art-4d1be12329c34362b16827cc5920227d2022-12-21T19:40:00ZengBMCBehavioral and Brain Functions1744-90812010-10-01615610.1186/1744-9081-6-56Intraindividual variability (IIV) in an animal model of ADHD - the Spontaneously Hypertensive RatSagvolden TerjePerry Guy MLFaraone Stephen V<p>Abstract</p> <p>Attention-deficit/hyperactivity disorder (ADHD) is characterized by numerous behaviors including inattention, hyperactivity and impulsiveness. ADHD-affected individuals also have high intra-individual variability (IIV) in reaction time. The genetic control of IIV is not well understood. The single study of the genetics of this phenomenon in humans detected only marginal associations between genotypes at two candidate genes for ADHD and variability in response time. The Spontaneously Hypertensive Rat (SHR/NCrl) is an animal model of ADHD, expressing high activity, inattention and impulsive behavior during operant and task tests. The SHR might be useful for identifying genes for variability, but it is not known whether it also expresses high IIV, as is symptomatic of ADHD. We therefore conducted an investigation of IIV in the SHR. We used 16 SHR/NCrl rats and 15 Wistar-Kyoto (WKY/Nico) controls applying a reinforcement schedule used in the validation of the SHR as an animal model of ADHD. We represented IIV as the average absolute deviation of individual behavior within the five 18-min segments of each experimental session from the average behavioral trait value within that session ('individual phenotypic dispersion', <it>PD<sub>i</sub></it>). <it>PD<sub>i </sub></it>for hyperactivity, impulsiveness and inattention in the SHR and WKY rats was analyzed using nonparametric ranking by experimental session. SHR/NCrl rats had higher <it>PD<sub>i </sub></it>than WKY/Nico controls for impulsiveness and inattention. There was a significant upward trend for <it>PD<sub>i </sub></it>over experimental segments within sessions for attention in SHR rats, but not in WKY. <it>PD<sub>i </sub></it>for hyperactivity was correlated with <it>PD<sub>i </sub></it>for impulsiveness and we therefore excluded observations associated with short IRTs (< 0.67s); dispersion in hyperactivity outside this interval was also significantly higher in SHR rats than in WKY rats. Some studies indicate the sharing of symptoms of hyperactivity and impulsiveness in SHR and ADHD-affected humans; high IIV in operant behavioral metrics suggests that the SHR may be useful in elucidating the genetic basis for IIV in humans.</p>http://www.behavioralandbrainfunctions.com/content/6/1/56 |
| spellingShingle | Sagvolden Terje Perry Guy ML Faraone Stephen V Intraindividual variability (IIV) in an animal model of ADHD - the Spontaneously Hypertensive Rat Behavioral and Brain Functions |
| title | Intraindividual variability (IIV) in an animal model of ADHD - the Spontaneously Hypertensive Rat |
| title_full | Intraindividual variability (IIV) in an animal model of ADHD - the Spontaneously Hypertensive Rat |
| title_fullStr | Intraindividual variability (IIV) in an animal model of ADHD - the Spontaneously Hypertensive Rat |
| title_full_unstemmed | Intraindividual variability (IIV) in an animal model of ADHD - the Spontaneously Hypertensive Rat |
| title_short | Intraindividual variability (IIV) in an animal model of ADHD - the Spontaneously Hypertensive Rat |
| title_sort | intraindividual variability iiv in an animal model of adhd the spontaneously hypertensive rat |
| url | http://www.behavioralandbrainfunctions.com/content/6/1/56 |
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