Beckett S R, Lawrence A J, Marsden C A, Marshall P W
Department of Physiology and Pharmacology, Medical School, Queen's Medical Centre, Nottingham, UK.
Psychopharmacology (Berl). 1992;108(1-2):110-4. doi: 10.1007/BF02245294.
The ability of 5-HT1 receptor agonists to modulate a chemically induced defence response has been studied in Lister hooded rats. Microinjections of the excitatory amino acid D,L-homocysteic acid (DLH) in both rostral and caudal dorsal periaqueductal gray matter (PAG) caused explosive motor behaviour characteristic of defence. This behaviour was quantified in terms of response duration, arena revolutions and number of defensive jumps. Direct administration into the PAG of either 5-carboxamidotryptamine (5-CT) or 8-hydroxy-2-(di-n-propylamino) tetralin (8-OHDPAT) produced behaviours (decreased exploratory rearing, dose related onset of flat body posture) indicative of 5-HT1A receptor activation. Pretreatment with either 5-CT or 8-OHDPAT directly in the PAG caused a significant attenuation, and in some cases a complete abolition, of the DLH evoked response. These agonists share high affinity in vitro for the 5-HT1A receptor. Thus the results suggest that in vivo activation of 5-HT1A receptors mediates an antiaversive response with respect to defensive behaviour elicited by specific chemical stimulation of the dorsal PAG.
已在利斯特戴帽大鼠中研究了5-羟色胺1（5-HT1）受体激动剂调节化学诱导防御反应的能力。在延髓和尾侧背侧导水管周围灰质（PAG）中微量注射兴奋性氨基酸D，L-高半胱氨酸（DLH）会引发具有防御特征的爆发性运动行为。这种行为根据反应持续时间、场地旋转次数和防御性跳跃次数进行量化。将5-羧基色胺（5-CT）或8-羟基-2-（二正丙基氨基）四氢萘（8-OHDPAT）直接注入PAG会产生表明5-HT1A受体激活的行为（减少探索性竖毛、剂量相关的平卧位姿势发作）。在PAG中直接用5-CT或8-OHDPAT预处理会导致DLH诱发反应显著减弱，在某些情况下会完全消除。这些激动剂在体外对5-HT1A受体具有高亲和力。因此，结果表明，5-HT1A受体的体内激活介导了对背侧PAG特定化学刺激引发的防御行为的抗厌恶反应。
