[Autonomic response to atropine and propranolol administration to rats with different behavioral characteristics].

A comparison was made between the characteristics of heart rate (HR) control in the norm, after biologically positive and negative influences (elaboration of alimentary instrumental reflexes and non-avoidable pain stimulation, respectively) in two groups of rats: those elaborating and non-elaborating avoidance of closed space at cries of the partner, according to P. V. Simonov (A and B groups), which is considered as manifestation of a weak (A group) and pronounced (B group) inborn passive defensive reaction to closed space. Greater enhancement of the HR background level (in conditions of non-rigid fixation) after a negative influence in B group and after positive in A group is connected to different significance of the reinforcements for the animals. The range of reactivity (the upper and lower HR boundaries determined by its acceleration under the action of atropin and its slowing under the action of propranolol) is connected to autonomous characteristics of vegetative regulation: stability in the group A and propensity for sharp shifts in the group B (expansion of the range of HR changes after positive influence and narrowing after negative one).