Malinow, M. R., Hill, J. D., Ochsner, A. J. 1974. Heart rate in caged rhesus monkeys (Macaca mulatta). Laboratory Animal Science 24, 537-540.

Heart rate of single-housed subjects increased coincident with human activity in the animal room, reaching peaks during feeding and cleaning.Heart beats/min measured via telemetry:Basal [before entering room] 138 +/- 25Person enters room: 150 +/- 25Person taps cage: 216 +/- 285 min after leaving room: 169 +/- 36 The rapid increase of 80 beats/min recorded when someone entered the room and tapped the cages is most probably related to the action of the autonomic nervous system and may explain the high heart rates reported in most studies of restrained or anesthetized monkeys. Thus, when the results of cardiovascular studies in rhesus monkeys are interpreted, the variables introduced by the sympathetic or parasympathetic nerves should be considered.