Salak-Johnson Janeen L, Anderson Deirdre L, McGlone John J
Department of Animal Sciences, University of Illinois, Urbana, IL 61801, USA.
Physiol Behav. 2004 Oct 30;83(1):143-50. doi: 10.1016/j.physbeh.2004.08.005.
The elevation of central corticotropin releasing factor (CRF) causes an increase in behavioral activity, including increases in overall activity and oral/nasal/facial (ONF) chewing-rooting-rubbing behaviors in the pig and similar behaviors in other species. This study detailed changes in the frequency, duration and sequences of behaviors after central administration of vehicle or porcine CRF (pCRF at 0.5, 5.0, 50 and 150 microg). A sequential analysis described the complex behaviors induced in a dose-dependent fashion by central pCRF. The frequency and duration of ONF behaviors were significantly increased among pigs receiving 50 microg of pCRF. For behaviors such as ONF, 50 microg represented a breakpoint at which the frequency and duration of single behaviors increased. Pigs receiving 50 microg of pCRF were considerably more active and exhibited more ONF behaviors than did pigs receiving lower doses. The highly sensitive sequential analysis revealed that very low doses of central pCRF induced subtle changes in sequences of behaviors. Low doses of central pCRF (0.5 microg) induced fear-related behavioral sequences that included ONF behaviors alternating with periods of inactivity. Central injection of astressin, a CRF receptor antagonist, blocked many, but not all, of CRF-induced behaviors. Compared with saline-injected control pigs, central pCRF increased general activity, ONF, fear-related freezing and sham chewing behaviors. When pCRF was given following astressin, fear-related freezing behaviors were not different compared with pigs receiving saline. However, pigs given astressin plus pCRF showed elevated sham chewing compared with saline-injected control pigs, as did pigs receiving intracerebroventricular (ICV) pCRF. These data indicate that central pCRF activates brain mechanisms associated with hyperactivity, ONF and fear-related behaviors, whereas other behaviors induced by pCRF may be nonspecifically mediated by CRF. Astressin antagonized some, but not all, pCRF-induced behaviors. This model represents the induction of hyperactivity and stereotyped behaviors, which may represent a new model for the study of mania or obsessive-compulsive behaviors.
中枢促肾上腺皮质激素释放因子（CRF）水平升高会导致行为活动增加，包括猪的整体活动增加以及口腔/鼻腔/面部（ONF）咀嚼-拱掘-摩擦行为增加，其他物种也有类似行为。本研究详细描述了给予载体或猪CRF（0.5、5.0、50和150微克的pCRF）后行为的频率、持续时间和序列变化。序列分析描述了中枢pCRF以剂量依赖性方式诱导的复杂行为。接受50微克pCRF的猪中，ONF行为的频率和持续时间显著增加。对于ONF等行为，50微克代表一个转折点，此时单个行为的频率和持续时间增加。接受50微克pCRF的猪比接受较低剂量的猪活跃得多，表现出更多的ONF行为。高度敏感的序列分析表明，极低剂量的中枢pCRF会诱导行为序列的细微变化。低剂量的中枢pCRF（0.5微克）会诱导与恐惧相关的行为序列，包括ONF行为与不活动期交替出现。中枢注射CRF受体拮抗剂阿斯特辛可阻断许多但并非所有CRF诱导的行为。与注射生理盐水的对照猪相比，中枢pCRF增加了一般活动、ONF、与恐惧相关的僵住和假咀嚼行为。在给予阿斯特辛后再给予pCRF时，与接受生理盐水的猪相比，与恐惧相关的僵住行为没有差异。然而，与注射生理盐水的对照猪相比，给予阿斯特辛加pCRF的猪假咀嚼行为增加，接受脑室内（ICV）pCRF的猪也是如此。这些数据表明，中枢pCRF激活了与多动、ONF和与恐惧相关行为相关的脑机制，而pCRF诱导的其他行为可能由CRF非特异性介导。阿斯特辛拮抗了部分但并非所有pCRF诱导的行为。该模型代表了多动和刻板行为的诱导，这可能代表了一种研究躁狂或强迫行为的新模型。
