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

CANZOBRE,M.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 teeth pulp, periodontium, and gingiva, is relayed in the trigeminal complex. Tooth pulp inflammation constitutesa common clinical problem, and this peripheral injury can induce neuroplastic changes in trigeminal nociceptive neurons. There is considerable evidence that the trigeminal subnucleus caudalis (Vc) is the principal relay for trigeminal nociceptive information as well as modulation of the painful stimuli. Glutamatergic primary afferentsinnervating the tooth pulp project to the most superficial laminae of the Vc. N-metthyl-D-aspartate receptor stimulation leads to the activation of the enzyme nitric oxide synthase (NOS), which synthesizes the free radical nitric oxide (NO). This enzyme is expressed mainly in lamina II interneurons, and in a small number of cells in lamina I as well as in deep laminae projection neurons of Vc. In the present study, we analyzed thetemporal changes in neuronal NOS (nNOS) in Vc local circuitries after unilateral intermediate molar pulp injury. Our results demonstrate that a peripheral dental pulpinjury leads to neuroplastic changes in the relative amount and activity of nNOS enzyme. Moreover, after a period of time, the nitrergic system shifts to the initialvalues, independently of the persistence of inflammation in the pulp tissues. VVC 2011 Wiley-Liss, Inc.