AJP - Regulatory, Integrative and Comparative Physiology, Vol 247, Issue 6 945-R952, Copyright © 1984 by American Physiological Society
Motor activity in decerebrate rats: spontaneous and nutrient-induced changes
J. Junquera, G. Lanzagorta-Sanchez, B. E. Mejia-Perez and R. Racotta
Bilateral decerebration was performed in adult Wistar rats of either sex
under pentobarbital sodium anesthesia. Decerebrate rats were aphagic and
adipsic and received 44 kcal/day subcutaneously by gastric intubation.
Their motor activity was recorded in the morning after an 18-h fast,
following various treatments: 10 ml mash (22 kcal) or 3.6 g glucose/kg;
intragastric, intraperitoneal, or subcutaneous injection of glucose (3.6
g/kg) or glycerol (1.84 g/kg); or injection of epinephrine (25
micrograms/kg ip or im). These treatments were also applied to control rats
previously maintained in the same conditions. Motor activity of both
operated and control rats was generally reduced in a similar manner:
intragastric mash greater than intraperitoneal glucose = intraperitoneal
glycerol greater than or equal to intragastric glucose greater than
intraperitoneal epinephrine. Subcutaneous glucose and glycerol and
intramuscular epinephrine produced hyperactivity, at least for the first 30
min. Thus decerebrate rats respond like normal rats by reducing their
general activity when subjected to the same satiating treatments given
intragastrically or intraperitoneally. This suggests that the brain stem of
rats can monitor peripheral information regarding caloric replenishment.
