Adult timing after preweaning shifts of Zeitgeber in rats: Crossed sensitization to time?

Preweaning albino rats were exposed from days 1 to 18 of life to successive 6-h shifts in light and temperature Zeitgebers, (1-18 rats), whereas controls (C) were raised under constant 12:12 L:D and temperature cycles. Cyclic Peak Interval performance at adulthood (100 days) showed that 1-18 rats were more accurate and sensitive to time than C subjects. These effects, which were akin to a crossed senzitization to time, were interpreted within the framework of scalar timing theory and the temporal information-processing model. They seemed not to depend upon changes in the pacemaker rate (lambda) or the memory constant K*, but to a change at the level of the decision process: 1-18 rats used a smaller response threshold than controls. (C) 1997 Elsevier Science Inc