Oliveira Leandro A, Pollo Taciana R S, Rosa Elinéia A, Duarte Josiane O, Xavier Carlos H, Crestani Carlos C
Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, Brazil.
Joint Federal University of São Carlos (UFSCar) - São Paulo State University (UNESP) Graduate Program in Physiological Sciences, São Carlos, Brazil.
Front Physiol. 2021 Aug 12;12:700540. doi: 10.3389/fphys.2021.700540. eCollection 2021.
The prelimbic (PL) and infralimbic (IL) subareas of the medial prefrontal cortex (mPFC) have been implicated in physiological and behavioral responses during aversive threats. The previous studies reported the noradrenaline release within the mPFC during stressful events, and the lesions of catecholaminergic terminals in this cortical structure affected stress-evoked local neuronal activation. Nevertheless, the role of mPFC adrenoceptors on cardiovascular responses during emotional stress is unknown. Thus, we investigated the role of adrenoceptors present within the PL and IL on the increase in both arterial pressure and heart rate (HR) and on the sympathetically mediated cutaneous vasoconstriction evoked by acute restraint stress. For this, bilateral guide cannulas were implanted into either the PL or IL of male rats. All animals were also subjected to catheter implantation into the femoral artery for cardiovascular recording. The increase in both arterial pressure and HR and the decrease in the tail skin temperature as an indirect measurement of sympathetically mediated cutaneous vasoconstriction were recorded during the restraint session. We observed that the microinjection of the selective α-adrenoceptor antagonist RX821002 into either the PL or IL decreased the pressor response during restraint stress. Treatment of the PL or IL with either the α-adrenoceptor antagonist WB4101 or the α-adrenoceptor antagonist reduced the restraint-evoked tachycardia. The drop in the tail skin temperature was decreased by PL treatment with the β-adrenoceptor antagonist propranolol and with the α- or α-adrenoceptor antagonists. The α-adrenoceptor antagonist into the IL also decreased the skin temperature response. Our results suggest that the noradrenergic neurotransmission in both PL and IL mediates the cardiovascular responses to aversive threats.
内侧前额叶皮质（mPFC）的前边缘区（PL）和下边缘区（IL）与厌恶威胁期间的生理和行为反应有关。先前的研究报道了应激事件期间mPFC内去甲肾上腺素的释放，并且该皮质结构中儿茶酚胺能终末的损伤影响了应激诱发的局部神经元激活。然而，mPFC肾上腺素能受体在情绪应激期间对心血管反应的作用尚不清楚。因此，我们研究了PL和IL内存在的肾上腺素能受体对急性束缚应激诱发的动脉压和心率（HR）升高以及交感神经介导的皮肤血管收缩的作用。为此，将双侧引导套管植入雄性大鼠的PL或IL中。所有动物还接受了股动脉导管植入以进行心血管记录。在束缚期间记录动脉压和HR的升高以及作为交感神经介导的皮肤血管收缩间接测量指标的尾部皮肤温度降低。我们观察到，将选择性α-肾上腺素能受体拮抗剂RX821002微量注射到PL或IL中可降低束缚应激期间的升压反应。用α-肾上腺素能受体拮抗剂WB4101或α-肾上腺素能受体拮抗剂处理PL或IL可减轻束缚诱发的心动过速。用β-肾上腺素能受体拮抗剂普萘洛尔以及α-或α-肾上腺素能受体拮抗剂处理PL可降低尾部皮肤温度的下降。向IL中注射α-肾上腺素能受体拮抗剂也可降低皮肤温度反应。我们的结果表明，PL和IL中的去甲肾上腺素能神经传递介导了对厌恶威胁的心血管反应。
