Fig. 3.

Diagram showing sites of lesions used to study long term effects on neurovascular transmission in arterial vessels of rats. (1) Transection of thoracic spinal cord without damage to preganglionic neurones. (2) Transection of paravertebral chain to remove preganglionic inputs (decentralization). (3) Transection of postganglionic nerves to denervate artery. Segments of artery were removed from the animals after 2–8 weeks and contractile responses to stimulation of perivascular sympathetic nerves were recorded during exposure to adrenoceptor antagonists and other drugs. that selectively interfere with neurovascular mechanisms