Skinner T L, Randall D C
J Auton Nerv Syst. 1985 Jan;12(1):23-34. doi: 10.1016/0165-1838(85)90038-4.
The purpose of this study was to examine the effects of behaviorally conditioned changes in autonomic activity on atrio-ventricular (AV) transmission in dog. To produce consistent activation of the cardiac nerves in the awake animal (n = 7), a classical appetitive conditioning paradigm was used. A conditioning trial consisted of a 30 s control period followed by one of two differing situations: (1) a 60-s conditional stimulus (CS+) tone wherein food (i.e. 'UCS' or unconditioned stimulus) was given during the last 30 s; or (2) at 30-s discriminative stimulus (CS-) tone which was never followed by food reward. Eight of each type trial were given daily until a stereotypic cardiovascular response was developed for the CS+ but not the CS-. The hemodynamic conditional response (i.e. 'CR', the response to the CS+) consisted of a moderate tachycardia (+14.5%, P less than or equal to 0.05), a small pressor response (+6.7%, P less than or equal to 0.01), and a moderate increase in the first time derivative of left ventricular pressure (+14.9%, P less than or equal to 0.01) reflecting an increase in inotropic state. The unconditional response (i.e., 'UCR', the response to the food reward) consisted of a substantial increase in HR (25.7%, P less than or equal to 0.01) above CR values while left ventricular pressure (LVP) and d(LVP)/dt increased 5.0% and 10.0% (P less than or equal to 0.01 for both) above their CR values. The effect of the conditioned changes in neural activity on the AV node was observed by pacing the atrium from 110 to 180 bpm during the first 15 s of each trial period (i.e. control, CS+, UCS). The discrepancy between the atrial pace rate and the transmitted ventricular rate is expressed as a 'mean difference score' and serves as an index of the fidelity of the AV transmission process: the smaller the difference, the closer a 1:1 ratio of atrial vs ventricular beats is approached. The relatively large mean difference score for the control periods (46.0 +/- 9 bpm) indicates that the paced atrial impulse did not faithfully precede ventricular contraction during these periods. The mean difference significantly decreased (34.6%, P less than or equal to 0.05) during the CS+, and approached an almost 1:1 ratio (75.6% decrease from CS+ values, P less than or equal to 0.01) during food delivery. beta-Adrenergic blockade (propranolol, 1 mg/kg, i.v.) eliminated the changes in mean difference during the CS+ but not during food delivery. There were no statistically significant physiological changes during CS-.(ABSTRACT TRUNCATED AT 400 WORDS)
本研究的目的是检测自主神经活动的行为条件性变化对犬房室（AV）传导的影响。为在清醒动物（n = 7）中持续激活心脏神经，采用了经典的食欲性条件反射范式。一次条件反射试验包括一个30秒的对照期，随后是两种不同情况之一：（1）一个60秒的条件刺激（CS +）音调，其中在最后30秒给予食物（即“UCS”或非条件刺激）；或（2）一个30秒的辨别刺激（CS -）音调，之后从不给予食物奖励。每天进行每种类型的试验各8次，直到对CS +形成刻板的心血管反应，而对CS -未形成。血液动力学条件反应（即“CR”，对CS +的反应）包括适度的心动过速（+14.5%，P≤0.05）、小的升压反应（+6.7%，P≤0.01）以及左心室压力一阶导数的适度增加（+14.9%，P≤0.01），反映心肌收缩力状态增加。非条件反应（即“UCR”，对食物奖励的反应）包括心率大幅高于CR值（25.7%，P≤0.01），而左心室压力（LVP）和d（LVP）/dt高于其CR值5.0%和10.0%（两者P均≤0.01）。在每个试验期的前15秒（即对照、CS +、UCS）期间，通过将心房起搏频率从110提高到180次/分钟来观察神经活动的条件性变化对房室结的影响。心房起搏频率与传导的心室频率之间的差异表示为“平均差异分数”，并作为房室传导过程保真度的指标：差异越小，心房与心室搏动的1:1比例越接近。对照期相对较大的平均差异分数（46.0±9次/分钟）表明在这些时期起搏的心房冲动不能忠实地先于心室收缩。在CS +期间，平均差异显著降低（34.6%，P≤0.05），在给予食物期间接近几乎1:1的比例（比CS +值降低75.6%，P≤0.01）。β - 肾上腺素能阻滞剂（普萘洛尔，1毫克/千克，静脉注射）消除了CS +期间平均差异的变化，但未消除给予食物期间的变化。在CS -期间没有统计学上显著的生理变化。（摘要截短于400字）
