Grottick Andrew J, Higgins Guy A
PRBN-B, F. Hoffmann-La Roche AG, 4070 Basel, Switzerland.
Psychopharmacology (Berl). 2002 Oct;164(1):33-41. doi: 10.1007/s00213-002-1174-3. Epub 2002 Jul 24.
In studies assessing sustained attention in humans, performance is often characterised by a decline in function over time. This response pattern, termed the vigilance decrement, is sensitive to manipulations affecting task difficulty, and to reversal with psychostimulant drugs. A valid test of attention in non-human species requires both comparable characteristics of performance, and sensitivity to similar psychoactive drugs. The five-choice serial reaction time task (5-CSRTT) has been described as a test of sustained attention in the rat, however, studies describing vigilance decrements and performance effects of psychostimulants in this task are scarce.
We manipulated the standard 5-CSRTT to determine under which conditions a replicable vigilance decrement could be observed, and sought to determine whether this pattern of changes was sensitive to psychostimulant administration.
One and two-year-old rats performed in five-choice sessions extended to 250 trials. Task difficulty was manipulated by either increasing or decreasing the duration of stimulus presentation, and pre-feeding studies were performed to control for effects of the additional food earned. In the two-year-old group dose-responses were then derived for nicotine (0.1-0.4 mg/kg), amphetamine (0.05-0.4 mg/kg) and caffeine (3-10 mg/kg).
Extending five-choice sessions revealed a decline in the performance of two-year-old rats as a function of trial number. Increasing task difficulty induced a response-decrement in one-year old rats; whilst reducing it enhanced the performance of two-year-old rats to that observed in younger subjects. Pre-feeding did not alter the response patterns observed in either group. Nicotine, amphetamine, and caffeine all reversed the performance decrement observed.
These results demonstrate that similar performance characteristics can be observed in both human and rat, serving to validate further the 5-CSRTT as a measure of sustained attention.
在评估人类持续注意力的研究中，表现通常以随着时间推移功能下降为特征。这种反应模式，即警觉性下降，对影响任务难度的操作敏感，并且对精神兴奋药物的逆转敏感。对非人类物种注意力的有效测试需要表现出类似的特征，以及对类似精神活性药物的敏感性。五选择连续反应时任务（5-CSRTT）已被描述为大鼠持续注意力的测试，然而，描述该任务中警觉性下降和精神兴奋药物对表现影响的研究很少。
我们对标准的5-CSRTT进行了操作，以确定在哪些条件下可以观察到可重复的警觉性下降，并试图确定这种变化模式是否对精神兴奋药物的给药敏感。
一岁和两岁的大鼠进行五选择实验，实验次数延长至250次。通过增加或减少刺激呈现的持续时间来操纵任务难度，并进行预喂食研究以控制额外获得食物的影响。然后在两岁组中得出尼古丁（0.1-0.4mg/kg）、苯丙胺（0.05-0.4mg/kg）和咖啡因（3-10mg/kg）的剂量反应。
延长五选择实验次数显示，两岁大鼠的表现随着实验次数的增加而下降。增加任务难度会导致一岁大鼠的反应下降；而降低任务难度则会将两岁大鼠的表现提高到年轻受试者的水平。预喂食并未改变两组观察到的反应模式。尼古丁、苯丙胺和咖啡因都逆转了观察到的表现下降。
这些结果表明，在人类和大鼠中都可以观察到类似的表现特征，这进一步验证了5-CSRTT作为持续注意力测量方法的有效性。
