Nicotinamide adenine dinucleotide phosphate/neuronal nitric oxide synthase-positive neurons in the trigeminal subnucleus caudalis involved in tooth pulp nociception

CANZOBRE, MARIELA C.; RIOS, H

JOURNAL OF NEUROSCIENCE RESEARCH

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2011 vol. 89 p. 1478 - 1488

0360-4012

Sensory information on facial structures, including teethpulp, periodontium, and gingiva, is relayed in the trigeminalcomplex. Tooth pulp inflammation constitutesa common clinical problem, and this peripheral injurycan induce neuroplastic changes in trigeminal nociceptiveneurons. There is considerable evidence that thetrigeminal subnucleus caudalis (Vc) is the principal relayfor trigeminal nociceptive information as well as modulationof the painful stimuli. Glutamatergic primary afferentsinnervating the tooth pulp project to the mostsuperficial laminae of the Vc. N-metthyl-D-aspartate receptorstimulation leads to the activation of the enzymenitric oxide synthase (NOS), which synthesizes the freeradical nitric oxide (NO). This enzyme is expressedmainly in lamina II interneurons, and in a small numberof cells in lamina I as well as in deep laminae projectionneurons of Vc. In the present study, we analyzed thetemporal changes in neuronal NOS (nNOS) in Vc localcircuitries after unilateral intermediate molar pulp injury.Our results demonstrate that a peripheral dental pulpinjury leads to neuroplastic changes in the relativeamount and activity of nNOS enzyme. Moreover, after aperiod of time, the nitrergic system shifts to the initialvalues, independently of the persistence of inflammationin the pulp tissues. VVC 2011 Wiley-Liss, Inc.