Subthalamic influences on the cardiorespiratory functions in the cat.

The electrical stimulation of the subthalamic nucleus (STN) caused a conspicuous increase in arterial blood pressure (BP), heart rate (HR) and respiratory rate (RR) in freely moving cats. The pulse pressure (PP) increased significantly following an initial decrease at the beginning of the 10 s long stimulation. A rebound bradycardia occurred after switching off the stimulation. Cardiorespiratory responses might be elicited also during ketamine-induced anaesthesia. The BP responses reduced highly under the blockade of the alpha(1)-adrenergic receptors. The neurotoxic lesions of the ipsilateral globus pallidus caused no significant alterations in the cardiorespiratory responses to STN stimulation. It is concluded that, besides its role in the motor control, STN is also involved in adjusting the cardiorespiratory functions to the somatomotor activity.