注意力缺陷多动障碍两种不同大鼠模型中的冲动选择——自发性高血压大鼠和基因敲除大鼠

Impulsive choice in two different rat models of ADHD-Spontaneously hypertensive and knockout rats.

作者信息

Carbajal Monica S, Bounmy Asiah J C, Harrison Olivia B, Nolen Hunter G, Regan Samantha L, Williams Michael T, Vorhees Charles V, Sable Helen J K

机构信息

Department of Psychology, University of Memphis, Memphis, TN, United States.

Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States.

出版信息

Front Neurosci. 2023 Jan 26;17:1094218. doi: 10.3389/fnins.2023.1094218. eCollection 2023.

DOI:10.3389/fnins.2023.1094218

PMID:36777639

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9909198/

Abstract

INTRODUCTION

Impulsivity is a symptom of attention-deficit/hyperactivity disorder (ADHD) and variants in the ) gene (OMIM 616417) have been linked to ADHD. This project utilized a delay-discounting (DD) task to examine the impact of deletion in rats on impulsive choice. "Positive control" measures were also collected in spontaneously hypertensive rats (SHRs), another animal model of ADHD.

METHODS

For Experiment I, rats were given the option to press one lever for a delayed reward of 3 food pellets or the other lever for an immediate reward of 1 pellet. Impulsive choice was measured as the tendency to discount the larger, delayed reward. We hypothesized that impulsive choice would be greater in the SHR and knockout (KO) rats relative to their control strains - Wistar-Kyoto (WKY) and wildtype (WT) rats, respectively.

RESULTS

The results did not completely support the hypothesis, as only the SHRs (but not the KO rats) demonstrated a decrease in the percent choice for the larger reward. Because subsequent trials did not begin until the end of the delay period regardless of which lever was selected, rats were required to wait for the next trial to start even if they picked the immediate lever. Experiment II examined whether the rate of reinforcement influenced impulsive choice by using a DD task that incorporated a 1 s inter-trial interval (ITI) immediately after delivery of either the immediate (1 pellet) or delayed (3 pellet) reinforcer. The results of Experiment II found no difference in the percent choice for the larger reward between KO and WT rats, demonstrating reinforcement rate did not influence impulsive choice in KO rats.

DISCUSSION

Overall, there were impulsivity differences among the ADHD models, as SHRs exhibited deficits in impulsive choice, while the KO rats did not.

摘要

引言

冲动是注意力缺陷多动障碍（ADHD）的一种症状，且（某）基因（在线人类孟德尔遗传数据库编号616417）的变异与ADHD有关。本项目利用延迟折扣（DD）任务来研究大鼠中（某基因）缺失对冲动选择的影响。还在另一种ADHD动物模型——自发性高血压大鼠（SHR）中收集了“阳性对照”指标。

方法

在实验I中，大鼠可选择按压一个杠杆以获得3颗食物颗粒的延迟奖励，或按压另一个杠杆以获得1颗食物颗粒的即时奖励。冲动选择通过对较大的延迟奖励打折扣的倾向来衡量。我们假设，相对于它们的对照品系——分别为Wistar-Kyoto（WKY）大鼠和（某基因）野生型（WT）大鼠，SHR和（某基因）敲除（KO）大鼠的冲动选择会更强。

结果

结果并未完全支持该假设，因为只有SHR（而非某基因KO大鼠）对较大奖励的选择百分比有所下降。由于无论选择哪个杠杆，后续试验直到延迟期结束才开始，所以大鼠即使选择了即时杠杆，也需要等待下一次试验开始。实验II通过使用一种DD任务来研究强化率是否影响冲动选择，该任务在即时（1颗食物颗粒）或延迟（3颗食物颗粒）强化物发放后立即设置1秒的试验间隔（ITI）。实验II的结果发现，某基因KO大鼠和WT大鼠对较大奖励的选择百分比没有差异，表明强化率并未影响某基因KO大鼠的冲动选择。