To address this question , we investigated the effects of the ( - adrenergic agonist l - isoproterenol or antagonist dl - propranolol on in vivo ltp of area ca1 and spatial learning in morris water maze 为此，我们观察了-受体激动剂异丙肾上腺素（ isoproterenol ）或拮抗剂心得安( propranolol )对在体ca1区ltp的调控作用以及对大鼠在morris水迷宫中空间学习的影响。
Accordingly , dl - propranolol impaired rat ' s spatial learning in the water maze when infused into area ca1 20min pretraining . compared with control rats , the dl - propranolol - treated rats showed significantly slower learning in the water maze and subsequently exhibited poor memory retention at 24 - hr 对应的，训练前20分钟在ca1区注射dl -心得安，大鼠在水迷宫中的学习速度显著慢于对照组，训练后24小时的空间记忆保持也相应地差。
In the presence of l - isoproterenol ( through local infusion into area ca1 ) , the theta - pulse stimulation with the parameter of 10 hz , 150 pulses / train , 1 train , a frequency weakly modifying synaptic strength , induced a robust ltp , and this effect was blocked when dl - propranolol was co - administered . by contrast , the theta - pulse stimulation with the parameter of 5 hz , 150 pulses / train , 3 train , a frequency strongly modifying synaptic strength , induced a significantly smaller ltp when dl - propranolol was administered into area ca1 正常情况下对突触传递效能仅有微小调制作用的10hz的(节律刺激（每串150个脉冲， 1串） ，在ca1区局部给予l -异丙肾上腺素后，显著地诱导出ltp ，这一效应可被dl -心得安所阻断；相反，正常情况下对突触传递强度有显著调制作用的5hz的(节律刺激（每串150个脉冲， 3串） ，在ca1区局部给予dl -心得安后，所诱导出的ltp被显著压抑。
