Vasodilator system for the face.

Area of Science:

• Neuroscience
• Physiology
• Vascular Biology

Background:

• Previous research indicated radiofrequency coagulation of the trigeminal ganglion caused facial flushing.
• This suggested a potential vasodilator pathway influencing facial blood vessels.

Purpose of the Study:

• To investigate and delineate a vasodilator system controlling blood flow to the face in cats.
• To understand the neural pathways involved in facial vasodilation.

Main Methods:

• Experiments were conducted on cats.
• Stereotaxic stimulation of facial and trigeminal nuclei in the brain stem was employed.
• Neural pathways involving the facial and trigeminal nerves were traced.

Main Results:

• A vasodilator system was identified originating from the brain stem with the facial nerve.
• This system travels via the greater superficial petrosal nerve to the trigeminal ganglion.
• Vasodilator fibers also directly exit the brain stem with the trigeminal nerve.
• Stimulation elicited vasodilator effects, confirming dual vasomotor control.

Conclusions:

• Cats possess a dual vasomotor control system for facial cutaneous blood vessels.
• This includes the classical sympathetic vasoconstrictor system and a newly described vasodilator system.
• The vasodilator system can produce significant changes in facial vessel caliber, opposing sympathetic effects.