Related Experiment Video
Updated: Mar 24, 2026

Optogenetic Entrainment of Hippocampal Theta Oscillations in Behaving Mice
Published on: June 29, 2018
Circadian rhythms in neuronal activity propagate through output circuits
Matthieu Cavey1,2, Ben Collins1, Claire Bertet1
1Department of Biology, New York University, New York, New York, USA.
Researchers identified leucokinin neuropeptide (LK) and its receptor (LK-R) as key signals in fruit flies that connect pacemaker neurons to behavioral rhythms, orchestrating activity and sleep patterns.
Area of Science:
- Neuroscience
- Chronobiology
- Genetics
Background:
- Circadian rhythms govern daily behaviors, driven by pacemaker neurons.
- The mechanism translating pacemaker neuron activity into whole-animal rhythms remains unclear.
Purpose of the Study:
- To identify signals linking circadian pacemaker neurons to output circuits controlling behavior.
- To elucidate how pacemaker neuron activity influences downstream neuronal circuits.
Main Methods:
- Screening for signals in Drosophila melanogaster.
- Investigating the role of leucokinin (LK) neuropeptide and its receptor (LK-R).
- Analyzing pacemaker neuron-dependent activity in LK/LK-R and DH44 neuron pathways.
Main Results:
- Leucokinin (LK) neuropeptide and its receptor (LK-R) are essential for normal behavioral rhythms.
- The LK/LK-R circuit connects pacemaker neurons to motor and sleep-regulating brain areas.
- Pacemaker neurons regulate rhythmic activity and excitability in LK/LK-R and DH44 neurons.
Conclusions:
- Rhythmic clock neuron activity is propagated to multiple downstream circuits.
- The leucokinin (LK) system is a critical circadian output pathway.
- This study reveals mechanisms for translating central clock signals into rhythmic behaviors.
More Related Videos
10:38Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
Published on: September 27, 2012
06:53Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures
Published on: November 11, 2016
Related Concept Videos
Circadian Rhythms and Gene Regulation
Circadian Rhythms and Gene Regulation
Neural Circuits
Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that...
The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential....
Neuronal Communication
Propagation of Action Potentials
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...