Publications by authors named "Thomas A Sontag"

The aim of the present study was to assess the effects of the neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4), which allows a depletion of noradrenergic terminals in a dose-dependent manner, on attention in rats as measured using the five-choice serial-reaction time task (5CSRTT). In addition, we investigated whether the effects of DSP4 treatment can be reversed by atomoxetine. Atomoxetine is a selective noradrenaline reuptake inhibitor and has been shown to be effective in the treatment of attention deficit hyperactivity disorder.

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The aim of this study was to assess the effects of the neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4) on attention in rats as measured using the 5-choice-serial-reaction-time task (5CSRTT) and to investigate whether methylphenidate has effects on DSP4-treated rats. Methylphenidate is a noradrenaline and dopamine reuptake inhibitor and commonly used in the pharmacological treatment of individuals with attention deficit/hyperactivity disorder (ADHD). Wistar rats were trained in the 5CSRTT and treated with one of three doses of DSP4 or saline.

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The present study investigated the effects of nutritional omega-3 polyunsaturated fatty acids on locomotor activity in spontaneously hypertensive rats (SHRs), which are used as an animal model of attention-deficit/hyperactivity disorder (ADHD). For 6 weeks, two groups of randomly assigned SHRs received food either enriched with or deficient in omega-3 fatty acids (based on the American Institute of Nutrition-93 G/AIN93G). Using an open field, locomotor activity was subsequently assessed for 6 days.

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The spontaneously hypertensive rat (SHR) is an established animal model of ADHD. It has been suggested that ADHD symptoms arise from deficits in executive functions such as working memory, attentional control and decision making. Both ADHD patients and SHRs show deficits in spatial working memory.

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The aim of the present study was to investigate the effect of DSP4-induced noradrenaline depletion on learning and memory in a spatial memory paradigm (holeboard). Since Harro et al. Brain Res 976:209-216 (2003) have demonstrated that short-term effects of DSP4 administration include both noradrenaline depletion and changes in dopamine and its metabolites-with the latter vanishing within 4 weeks after the neurotoxic lesion-the behavioural effects observed immediately after DSP4 administration cannot solely be related to noradrenaline.

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In this experiment, we have investigated the spatial memory performance of rats following a central noradrenaline depletion induced by three different doses of the neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4) and following administration of three different doses of methylphenidate (MPH). The rats were required to find food pellets hidden on a holeboard. The sole administration of DSP4 induced only minor cognitive deficits.

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Attention deficit/hyperactivity disorder (ADHD) involves clinically heterogeneous problems including attention deficits, behavioural hyperactivity and impulsivity. Several animal models of ADHD have been proposed, ranging from models with neurotoxic lesions to genetically manipulated animals. An ADHD model is supposed to show phenomenological similarities with the disorder, i.

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The comprehensive and stress-free assessment of various aspects of learning and memory is a prerequisite to evaluate mouse models for neuropsychiatric disorders such as Alzheimer's disease or attention deficit/hyperactivity disorder (ADHD). COGITAT is an automated holeboard system allowing simultaneous assessment of spatial working and reference-memory performance which we have adapted in this study to enable its usage with mice. The holeboard apparatus consists of an open-field chamber with a 25-hole floor insert, each hole being monitored by infrared light beams, located on three different levels, allowing the distinction between visits of holes, i.

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Impairments of attention are cardinal features of attention deficit hyperactivity disorder (ADHD) and can seriously affect the daily life of children with ADHD. Despite effective treatment strategies, there is a need of further treatment options that can be added to available and well established treatments. Further treatment options are needed since available treatments are often time consuming, expensive and limited regarding their external validity.

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Objective: Two studies were performed to assess both divergent and convergent thinking in adults with ADHD.

Method: The first study compared the problem-solving abilities of healthy participants (N = 144) and unmedicated adults with ADHD (N = 144). In the second study, problem-solving abilities of adults with diagnosed ADHD (N = 22) were examined twice, that is, on and off methylphenidate (MPH), and compared with the performance of a healthy control group (N = 22).

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Obsessive-compulsive disorder (OCD) is characterized by recurrent, intrusive and disturbing thoughts as well as by repetitive stereotypic behaviors. Epidemiological data are similar in children and adults, i.e.

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1-Trichloromethyl-1,2,3,4-tetrahydro-beta-carboline (TaClo) is neurotoxic when administered to the brain and alters motor behaviour following intraperitoneal administration. We have assessed the long-term effects of oral TaClo administration on nocturnal motor behaviour in rats. Two groups of rats received TaClo orally at a dose of either 0.

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The aim of the present study was to determine whether malingering of adult attention deficit hyperactivity disorder (ADHD) can be detected using a self-report rating scale. A sample of 78 university students was allocated to three different conditions. The conditions were (a) a control group, (b) a naïve simulation group and (c) a coached simulation group.

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Objective: The present article tests the hypothesis of a sustained attention deficit in children and adults suffering from ADHD.

Method: Vigilance and sustained attention of 52 children with ADHD and 38 adults with ADHD were assessed using a computerized vigilance task. Furthermore, the attentional performance of healthy children (N = 52) and healthy adults (N = 38) was examined.

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In laboratory tasks, caffeine has been shown to improve psychomotor performance. The aim of the present experiment was to assess the effects of caffeine on a skilled everyday life task in habitual caffeine consumers. The assessment of handwriting movements of 20 adults was performed following the administration of 0mg/kg (placebo), 1.

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