en Pharmacokinetics/Dynamics Pharmacokinetics/Dynamics Experimental research article Experimental research article <div style="text-align: justify;"><strong>Introduction:</strong> The basolateral amygdala (BLA) is implicated in stress-related disorders such as anxiety-like behavior. Substantial data exist demonstrating a close relationship between anxiety and adrenergic receptor function in patients with anxiety disorders; however, little is known about the effects of the &beta;1 adrenergic receptor in the BLA on anxiety. This experiment examined the effects of the &beta;1 adrenergic receptor in the BLA on anxiety-like behavior. <strong>Methods:</strong> Male Wistar rats were exposed to foot-shock stress four consecutive days that were uncontrollable. The &beta;1-adrenoreceptor agonist (dobutamine; 0.5&mu;l/side) or antagonist (atenolol; 0.25&mu;l/side) bilaterally infused into the BLA five minutes before foot-shock stress. Anxiety-like behaviors were assessed 24h after four consecutive day&rsquo;s uncontrollable stress using elevated plus-maze (EPM) and open field test (OFT). <strong>Results:</strong> Findings of EPM revealed that foot-shock stress leads to anxiogenic effect with reduction the time spent and the number of entries into the open arms and increased head-dipping. Intra-BLA infusions of atenolol before stress affected animal behavior differently, such that it significantly increased the time spent and the number of entries into the open arms and decreased head-dipping. Also, OFT results showed the intra-BLA infusion of atenolol increased the time periods spent in the center, number of center entries and reduced the number of rearing as compared with the stress group. <strong>Conclusion:</strong> These results suggest that the anxiety-like behavior observed after the foot-shock stress is mediated, in part, by exaggerated &beta;1 adrenergic receptor acting at the BLA.</div> Anxiety-like behaviour, Basolateral amygdala, β1-Adrenergic receptor, Stress. 101 114 http://ppj.phypha.ir/browse.php?a_code=A-10-1156-1&slc_lang=en&sid=1 Leila Hosseinmardi leilahosseinmardi@damghaniau.ac.ir 3200319475328460029574 3200319475328460029574 No Department of Biology, Islamic Azad University, Damghan Branch, Damghan, Iran Abdolhossein Shiravi shiravi@damghaniau.ac.ir 3200319475328460029575 3200319475328460029575 No Department of Biology, Islamic Azad University, Damghan Branch, Damghan, Iran Gholam Hossein Meftahi hossein.meftahi@bmsu.ac.ir 3200319475328460029576 3200319475328460029576 Yes Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran Mohammad Reza Afarinesh r.afarinesh@kmu.ac.ir 3200319475328460029577 3200319475328460029577 No Kerman Neuroscience Research Center, Institute of Neuropharmachology, Kerman University of Medical Sciences, Kerman, Iran