The effect of systemic cocaine on spinal nociceptive reflex activity in the rat.
In the anesthetized rat, cocaine (25 mg/kg i.p.), enhanced the frequency potentiation of nociceptively evoked polysynaptic discharges but did not affect the polysynaptic reflex discharge to single nociceptive stimuli or the habituation of this reflex to repetitive pinch stimuli. The non-nociceptive, short-latency reflex discharge was suppressed for 10-15 min after cocaine administration. The neurogenic extravasation response to antidromic cutaneous C-fiber stimulation was unaffected by cocaine. These findings suggest that systemic cocaine, in doses analgesic for the rat, does not suppress spinal nociceptive reflexes.
Pertovaara
A
A
Department of Physiology, University of Michigan, Ann Arbor 48109.
Belczynski
C R
CR
Morrow
T J
TJ
Casey
K L
KL
D000200:Action Potentials / Q000187:drug effects; D000344:Afferent Pathways / Q000187:drug effects / Q000503:physiopathology; D000818:Animals; D003042:Cocaine / Q000008:administration & dosage*; D004558:Electric Stimulation; D007274:Injections, Intraperitoneal; D008297:Male; D010146:Pain / Q000503:physiopathology*; D010543:Peroneal Nerve / Q000187:drug effects / Q000503:physiopathology; D051381:Rats; D011919:Rats, Inbred Strains; D012018:Reflex / Q000187:drug effects; D013116:Spinal Cord / Q000187:drug effects / Q000503:physiopathology*; D013497:Sural Nerve / Q000187:drug effects / Q000503:physiopathology
D003042:Cocaine