López-Grancha M, Lopez-Crespo G, Sanchez-Amate M C, Flores P
Departmento de Neurociencia y Ciencias de la Salud, Universidad de Almería, La Cañada, Almería, Spain.
Psychopharmacology (Berl). 2008 Apr;197(3):487-98. doi: 10.1007/s00213-007-1059-6. Epub 2008 Mar 6.
The research of individual differences has opened new possibilities for better exploring the neurobiological basis of vulnerability to psychopathological disorders.
We extended this approach by using schedule-induced polydipsia (SIP).
Outbred male Wistar rats were characterized as either high (HD) or low (LD) drinker according to their behavior in SIP. Subsequently, their performance in the elevated plus maze (EPM) was studied for possible differences in anxiety-like behaviors. Finally, the effects of pentylenetetrazol (PTZ), diazepam, d-amphetamine, and cocaine on individual differences in SIP were investigated.
HD rats acquired SIP faster and reached higher asymptotic levels than LD. Nose pokes, however, were greater in LD. In the EPM, there were no differences between HD and LD animals. Gabaergic drug effects on SIP did not differ between HD and LD rats. Compared to saline, PTZ reduced and diazepam increased water SIP drinking. On the other hand, amphetamine dose-dependently reduced SIP in HD, whereas the highest dose was required to reduce SIP in LD. HD rats also showed reductions in SIP drinking after cocaine administration. However, the effects of these drugs on nose pokes did not differ between HD and LD.
These data provide novel evidence that individual differences in SIP are not predictive of behavioral reactivity in animal models of anxiety and suggest an important role for the dopaminergic system in such individual differences. These findings point to SIP as a useful animal model for investigating the neurobiological basis of vulnerability to several psychopathologies in which the dopaminergic system is involved.
个体差异的研究为更好地探索精神病理障碍易感性的神经生物学基础开辟了新的可能性。
我们通过使用定时诱导多饮（SIP）扩展了这种方法。
根据雄性远交系Wistar大鼠在SIP中的行为，将其分为高饮者（HD）或低饮者（LD）。随后，研究它们在高架十字迷宫（EPM）中的表现，以探究焦虑样行为的可能差异。最后，研究了戊四氮（PTZ）、地西泮、d-苯丙胺和可卡因对SIP个体差异的影响。
HD大鼠比LD大鼠更快获得SIP，且达到更高的渐近水平。然而，LD大鼠的鼻触次数更多。在EPM中，HD和LD动物之间没有差异。HD和LD大鼠之间，GABA能药物对SIP的影响没有差异。与生理盐水相比，PTZ减少而地西泮增加了SIP饮水。另一方面，苯丙胺在HD中剂量依赖性地减少SIP，而在LD中需要最高剂量才能减少SIP。HD大鼠在给予可卡因后SIP饮水也减少。然而，这些药物对鼻触次数的影响在HD和LD之间没有差异。
这些数据提供了新的证据，表明SIP中的个体差异不能预测焦虑动物模型中的行为反应性，并表明多巴胺能系统在这种个体差异中起重要作用。这些发现表明SIP是一种有用的动物模型，可用于研究多巴胺能系统参与的几种精神病理学易感性的神经生物学基础。
