Characterization of neurons in the area of the medullary lateral reticular nucleus responsive to noxious visceral and cutaneous stimuli.
Brain Res
; 802(1-2): 163-74, 1998 Aug 17.
Article
em En
| MEDLINE
| ID: mdl-9748555
ABSTRACT
In halothane-anesthetized rats, 283 caudal medullary neurons responsive to colorectal distension (CRD) were characterized using extracellular electrodes. Neurons inhibited by CRD (n = 82) were in the area dorsal to the lateral reticular nucleus (LRN). Most neurons excited by CRD (n = 130) were located within or immediately adjacent to the LRN, were excited by noxious heat and/or noxious pinch of at least half the body surface and were called bilateral nociceptive specific (bNS) neurons. bNS neurons had accelerating responses to graded CRD (threshold 20 +/- 2 mmHg). Ten of twelve bNS neurons tested could be antidromically activated by electrical stimulation of the midline cerebellum. Other neurons excited by CRD (n = 71) had mixed responses to cutaneous stimuli and were generally located in the area dorsal to the LRN. Increases in blood pressure due to intravenous phenylephrine did not significantly alter the spontaneous activity of neurons excited by CRD, but altered spontaneous activity (12 excited, four inhibited) in all neurons tested which were inhibited by CRD. Decreases in blood pressure produced by intravenous nitroprusside produced a reciprocal response in most neurons inhibited by CRD and had a delayed onset (20-30 s after bolus administration) excitatory effect on 21 of 27 units excited by CRD. Combined with other studies, these data suggest a role for neurons within and adjacent to the LRN in the modulation of visceral nociception. They also implicate a role for the cerebellum in visceral nociceptive processing.
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Base de dados:
MEDLINE
Assunto principal:
Dor
/
Pele
/
Vísceras
/
Bulbo
/
Neurônios
Limite:
Animals
Idioma:
En
Revista:
Brain Res
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Estados Unidos