Spinal cord, hypothalamic and air temperature : interaction with arousal states in the marmot [Moelle épinière, température hypothalamique et ambiante : interaction avec les états d'éveil chez la marmotte].

Résumé

Yellow-bellied marmots, Marmota flaviventris, prepared with U-shaped thermodes in the epidural space of the thoracic vertebral canal, a thermode in the preoptic hypothalamus, and cortical surface and hippocampal electrodes, were used to investigate the interaction of arousal states with temperature regulation. It was found that arousal state of the animal influences the thermoregulatory responses initiated in either the spinal cord or hypothalamus. Further, changes in ambient temperature affected both the gain and the threshold of these responses. The interaction of the hypothalamus and spinal cord was not an additive function, however the threshold for shivering of each could be altered by temperature manipulation of the other. Future studies in modeling of temperature regulation should consider the contributions of temperature receptors of the spinal cord and the arousal state of the animal during the stimulation period. Des marmottes ayant des thermodes implantées dans l'espace épidural du canal vertébral thoracique, dans l'hypothalamus et la surface corticale et des électrodes dans l'hippocampe sont utilisées pour connaître l'interaction des états d'éveil avec la régulation de la température.