Gross anatomical study of the sympathetic cardiac nerves in the house musk shrew (Suncus murinus).

The sympathetic cardiac nerves originating from the cervical and upper thoracic sympathetic ganglia in the house musk shrew (Suncus murinus) were examined using macroscopic and whole-mount immunohistochemical methods. Based on the results, the nerves were macroscopically classified into the following three groups: nerves innervating the cervical sympathetic ganglia mainly to the arterial porta of the heart; nerves supplying the stellate and thoracic sympathetic ganglia at the level of T2-T5 or T6 for both the arterial and venous portae of the heart; and nerves innervating the thoracic sympathetic ganglia at the level of T4-T9 to the esophagus and lung and then the heart via the blood vessels within the mediastinal pleura. These findings in the house musk shrew suggest a possible primitive morphological pattern of the cervical and thoracic sympathetic nervous system that may be related to those in other mammals, including humans.