Back-firing of ventromedial medulla neurons from the spinal cord in awake, freely moving rats.
In the awake, freely moving rat we showed, by means of single-unit recordings and antidromic spinal cord activation, that at the ventromedial medulla level, in these particular experimental conditions, the 'multimodal, multireceptive' units excited by auditory, cutaneous non-noxious and noxious stimuli are possibly involved in a spinal descending control system. These neurons were back-fired from the medial part of the lateral funiculus, hence they probably projected to the dorsal and intermediate horn of the cord, and not to the ventral horn, which emphasizes a role in the control of nociception. Due to their convergent properties, these units are probably involved in nonspecific aspects of nociception such as alertness or stress.
Martin
G
G
Unité de Physiopharmacologie du Système Nerveux de l'INSERM, U.161, Paris, France.
Oliveras
J L
JL
Montagne-Clavel
J
J
D000200:Action Potentials; D000818:Animals; D004525:Efferent Pathways / Q000502:physiology; D008526:Medulla Oblongata / Q000166:cytology / Q000502:physiology*; D009431:Neural Conduction; D011903:Raphe Nuclei / Q000166:cytology / Q000502:physiology*; D051381:Rats; D013116:Spinal Cord / Q000166:cytology / Q000502:physiology*; D013312:Stress, Physiological / Q000503:physiopathology; D014851:Wakefulness / Q000502:physiology