The times of our lives (and of our brains): from interval to circadian timing

GOLOMBEK D.A.; BUSSI I.L.; AGOSTINO P.V.

Coimbra

Conferencia; First International Conference on Time Perspective; 2012

Neural timing mechanisms range from the millisecond to diurnal, and possibly annual, frequencies. Two of the main processes under study are the interval timer (seconds-to-minute range) and the circadian clock. The molecular basis of these two mechanisms is the subject of intense research, as well as their possible relationship. Many different studies concerning a possible interaction between interval timing and circadian timing have been performed. This presentation will summarize data from timing studies and reviews the molecular basis of both interval and circadian timing, including the discussion of the contribution from studies of genetically modified animal models. We propose that there might be a common neurochemical substrate for timing mechanisms in the brain related to dopamine reward systems. In addition, a circadian modulation of interval timing suggests an intermodulation of different frequencies in cerebral timing processes. Temporal perception is fundamental to environmental adaptation in humans and other animals. To deal with timing, organisms have developed multiple systems that are active over a wide range of magnitude, the most important being circadian timing, interval timing and millisecond timing. Time estimation in the second-to-minutes range - known as interval timing - involves the interaction of the basal ganglia, striatum and prefrontal cortex. We have previously reported that short-time perception in mice is influenced by the circadian pacemaker. We are currently testing the hypothesis that dopamine signaling is involved in the interaction between circadian and interval timing, being melatonin a key element in the regulation of these signaling pathways. In addition, we are looking into the role of clock genes in areas related to interval timing mechanisms. It’s not just time that waits for nobody, but times that might be subtly interrelated in our body clocks.