Conversion of parasympathetic nerve function from prejunctional inhibition to postjunctional excitation following sympathectomy of rat periorbital smooth muscle.
Parasympathetic innervation of rat periorbital smooth muscle normally inhibits excitatory sympathetic neurotransmission but does not directly affect muscle tone. Five weeks after sympathetic denervation, however, parasympathetic stimulation now elicits contractions. These are blocked by atropine, indicating establishment of muscarinic cholinergic neuromuscular transmission. Conversion to excitation is not accompanied by enhanced smooth muscle responsiveness to muscarinic stimulation, indicating that prejunctional alterations are responsible.
Smith
P G
PG
Department of Physiology, University of Kansas Medical Center, Kansas City 66160-7401.
Beauregard
C L
CL
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004558:Electric Stimulation; D005260:Female; D005728:Ganglia, Sympathetic / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009130:Muscle, Smooth / Q000294:innervation* / Q000502:physiology; D009469:Neuromuscular Junction / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology; D018377:Neurotransmitter Agents / Q000378:metabolism; D009915:Orbit / Q000294:innervation / Q000502:physiology; D010275:Parasympathetic Nervous System / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013562:Sympathectomy
D018377:Neurotransmitter Agents; D001285:Atropine