INVESTIGADORES
VALENTINUZZI veronica Sandra
congresos y reuniones científicas
Título:
Daily rhythm of metabolic rate in the tuco-tuco (Ctenomys aff. knighti), a subterranean rodent
Autor/es:
TACHINARDI P; TØIEN O; BUCK LC; ODA GA; VALENTINUZZI VS
Lugar:
Mendoza
Reunión:
Congreso; XII Latin American Symposium on Chronobiology-LASC; 2013
Resumen:
Tuco-tucos (Ctenomys aff. knighti) are subterranean
rodents which occur in Northwest Argentina. They are nocturnal in the lab,
showing daily activity and body temperature (Tb) rhythms. However,
in the field they are observed aboveground during the daylight hours on a daily
basis. It has been suggested that this switch in phase of activity between field and lab might be related to differences
in energy requirements of these two conditions. To approach this hypothesis, we began to study the energetics of C.
aff. knighti by characterizing their daily metabolic rate (MR)
rhythm in
the lab. We measured O2 consumption (using flow-through
respirometry), Tb and motor activity in 4 adults housed individually.
Animals were fed ad lib and kept under LD12:12 (L=200 lux) and at 23±1oC.
In the 3 days prior to respirometry measures we kept animals in unsealed cages
with running wheels. In the following 3 days we placed them in sealed
respirometry chambers without wheels. Then we inserted wheels in the sealed
chambers for 3 days. Finally, animals were removed from the respirometry
chambers and Tb and activity were recorded for 2 more days. MR range
was 0.63-2.09 mLO2
g-1 h-1 1 in a 140g-individual and 0.34-2.79 mLO2 g-1
h-1 in a 200g-animal. The other animals displayed MR within
these ranges. Surprisingly, 3 tuco-tucos changed their previous nocturnal
pattern when placed in the respirometry chamber. One became diurnal while 2
became crepuscular. These animals also did not run on the wheel. Interestingly, the only individual which ran
on the wheel remained nocturnal. MR followed the same rhythmic pattern as
activity and Tb in all animals. Further studies will be conducted to
investigate the variability in rhythmic patterns upon housing in the
respirometry chamber.