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The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...

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Related Experiment Video

Updated: May 27, 2026

Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures

Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures

Published on: November 11, 2016

The circadian clock, reward, and memory.

¹Unit of Biochemistry, Department of Biology, University of Fribourg Fribourg, Switzerland.

Frontiers in Molecular Neuroscience

|November 16, 2011

Summary

This summary is machine-generated.

The time of day influences cognitive performance and reward-seeking behaviors. This review explores how the circadian clock affects addiction, mood, and memory.

Keywords:

addiction cell death circadian rhythms cortisol neurogenesis synaptic plasticity

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Area of Science:

Neuroscience
Chronobiology
Behavioral Science

Background:

Daily cognitive performance fluctuates, often correlating with reward cravings.
The relationship between time of day, cognitive function, and reward seeking is complex.

Purpose of the Study:

To review the influence of the circadian clock on addiction and mood.
To contextualize these findings within memory processes.

Main Methods:

Literature review of existing studies.
Synthesis of data on circadian rhythms, behavior, and cognition.

Main Results:

Circadian rhythms significantly impact mood regulation and susceptibility to addiction.
Daily cycles affect reward processing and decision-making relevant to addictive behaviors.

Conclusions:

Understanding circadian influences is crucial for addressing mood disorders and addiction.
The interplay between circadian timing, reward, and memory offers new therapeutic targets.