Is there decussation in the central autonomic network (CAN)?

Abstract

The hypothalamus receives various types of stress information from the outside world through the prefrontal cortex, limbic system, and other cerebral networks. The autonomic neural network of the brainstem and spinal cord consists of the descending autonomic pathways from the hypothalamus to the preganglionic autonomic neurons and the ascending autonomic pathways carrying afferent information from visceral organs. In this paper, we define the hypothalamus and the cerebral neural network projecting to the hypothalamus as the upper part of the central autonomic network (CAN) and the autonomic neural network of the brainstem and spinal cord as the lower part of the CAN, and surveyed the literature for findings on decussation (neural crossing) of the CAN. The ascending autonomic pathways carrying afferent information from visceral organs cross at the level of the spinal cord. The descending sympathetic pathways from the hypothalamus to the lateral horns of the spinal cord cross in part at the level of the midbrain. The sympathetic descending tracts of the thermotropic sweat-accelerating pathway cross at the medullary-spinal cord transition zone and at the level of the spinal cord. According to clinical reports of hemiplegic patients with unilateral cerebral stroke, impairment of skin temperature and sweating is observed in the limbs contralateral to stroke lesions. Thus, the descending autonomic pathways involved in thermogenic sweating are presumed to cross at any level of the brainstem or spinal cord. The mystery of whether there is decussation in the central control circuits of the autonomic nervous system is a remaining frontier.