Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Circadian Rhythms and Gene Regulation02:19

Circadian Rhythms and Gene Regulation

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,...
Drugs Affecting Neurotransmitter Synthesis01:29

Drugs Affecting Neurotransmitter Synthesis

Drugs affecting neurotransmitter synthesis can impact the adrenergic neuron and the synthesis of neurotransmitters. For example, α-methyltyrosine and carbidopa target specific enzymes involved in catecholamine synthesis. α-methyltyrosine inhibits the enzyme tyrosine hydroxylase, which converts tyrosine into dopamine. By blocking this enzyme, α-methyltyrosine reduces dopamine production and other catecholamines. Carbidopa, on the other hand, inhibits the enzyme dopa decarboxylase, which converts...
Parkinson Disease l: Introduction01:24

Parkinson Disease l: Introduction

Parkinson’s disease is a chronic, progressive neurodegenerative disorder that primarily affects movement. It is characterized by motor symptoms such as resting tremors, muscle rigidity, bradykinesia (slowness of movement), and postural instability. Patients may notice hand tremors at rest, stiffness during movement, or a shuffling gait. In addition to motor features, non-motor symptoms include sleep disturbances, mood and behavioral changes, constipation, and cognitive impairment, all of which...
Parkinson Disease ll: Pathophysiology01:24

Parkinson Disease ll: Pathophysiology

Parkinson disease (PD) is a progressive neurodegenerative disorder primarily affecting movement, with additional non-motor features. Its pathophysiology involves complex interactions among genetic susceptibility, environmental exposures, and cellular dysfunction, including dopaminergic neuron loss, protein aggregation, and mitochondrial impairment.Selective NeurodegenerationA key feature is the degeneration of dopaminergic neurons in the substantia nigra pars compacta, leading to reduced...
Biological Clocks and Seasonal Responses02:45

Biological Clocks and Seasonal Responses

The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
Positive Regulator Molecules02:39

Positive Regulator Molecules

Mitotic cell division results in daughter cells that exactly resemble the parent cell. However, errors in the DNA replication or distribution of genetic material may lead to genetic mutations that may be passed down to every new cell formed from the resulting abnormal cell. Propagation of such mutant cells is restricted through checkpoint mechanisms present at different stages of the cell cycle. These checkpoints involve regulator molecules that either promote or demote cell cycle events.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Essential Information About Chronobiology and Chronotherapy for the Optimal Care of People With Bipolar Disorders: An Expert Consensus.

Bipolar disorders·2026
Same author

Prenatal circadian rhythm disruption induces sex-specific substance use and mood-related phenotypes in mice.

bioRxiv : the preprint server for biology·2026
Same author

Acute Sleep Deprivation in Adolescence Produces Transcriptional Changes in the Orexin System and Regulates Motivation for Reward.

Biological psychiatry global open science·2026
Same author

Impact of ClockΔ19 mutation on neural recording performance and neural inflammatory responses.

Biomaterials·2026
Same author

Tonic dopamine sensing reveals a D2 and D3-mediated dopamine response to raclopride in <i>Clock</i>Δ<i>19</i> mice model.

Npj biosensing·2026
Same author

Unraveling Tissue-Specific Molecular Signatures and Convergent Pathway Enrichments in Suicidal Behavior.

bioRxiv : the preprint server for biology·2026

Related Experiment Video

Updated: May 20, 2026

Circadian Entrainment of Drosophila Melanogaster
07:12

Circadian Entrainment of Drosophila Melanogaster

Published on: June 3, 2020

A mutation in CLOCK leads to altered dopamine receptor function.

Sade Spencer1, Melissa I Torres-Altoro, Edgardo Falcon

  • 1Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, USA.

Journal of Neurochemistry
|July 5, 2012
PubMed
Summary

Mice lacking the Clock gene show increased dopamine release and altered dopamine receptor levels, impacting behavior and reward pathways. These findings clarify dopaminergic system abnormalities linked to mood and addiction.

More Related Videos

Developing a Rat Model for Bipolar Disorder
04:42

Developing a Rat Model for Bipolar Disorder

Published on: May 2, 2025

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
10:38

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters

Published on: September 27, 2012

Related Experiment Videos

Last Updated: May 20, 2026

Circadian Entrainment of Drosophila Melanogaster
07:12

Circadian Entrainment of Drosophila Melanogaster

Published on: June 3, 2020

Developing a Rat Model for Bipolar Disorder
04:42

Developing a Rat Model for Bipolar Disorder

Published on: May 2, 2025

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
10:38

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters

Published on: September 27, 2012

Area of Science:

  • Neuroscience
  • Behavioral Genetics
  • Molecular Biology

Background:

  • Mice with Clock gene mutations (ClockΔ19) exhibit behavioral changes suggesting altered dopaminergic transmission.
  • These include hyperactivity, increased exploration, and heightened reward sensitivity to drugs of abuse.
  • The precise dopaminergic mechanisms driving these behaviors are not fully understood.

Purpose of the Study:

  • To investigate the effects of Clock gene loss on dopaminergic transmission in mice.
  • To elucidate the molecular and functional consequences of altered dopaminergic tone on dopamine receptor expression and signaling.
  • To understand the link between Clock gene function and behaviors related to mood, activity, and addiction.

Main Methods:

  • Analysis of dopamine metabolites (HVA, DOPAC) in striatum.
  • Assessment of sensitivity to dopamine receptor antagonists.
  • Quantification of dopamine receptor (D1, D2) protein levels.
  • Evaluation of locomotor responses to dopamine receptor agonists and cAMP activation.

Main Results:

  • Loss of CLOCK function increased dopamine release and turnover in the striatum.
  • Enhanced sensitivity to dopamine receptor antagonists was observed.
  • Dopamine receptor D1 and D2 protein levels were augmented, with a shift favoring D2 receptor signaling.
  • Mutant mice showed altered locomotor responses to specific agonists and a blunted cAMP response.

Conclusions:

  • CLOCK deficiency leads to increased dopaminergic tone and altered dopamine receptor expression and signaling.
  • These neurochemical and molecular changes underlie the observed behavioral phenotypes in ClockΔ19 mice.
  • The study provides insights into the role of the Clock gene in regulating dopaminergic pathways involved in behavior and addiction.