Related Experiment Video
Updated: Feb 5, 2026
08:47
Live Images of GLUT4 Protein Trafficking in Mouse Primary Hypothalamic Neurons Using Deconvolution Microscopy
Published on: December 7, 2017
10.2K
Activation of medial hypothalamic orexin neurons during a Go/No-Go task
Linnea R Freeman1, Gary Aston-Jones2
1Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, United States; Department of Biology, Furman University, Greenville, SC 29613, United States.
Brain Research
|September 4, 2018
Summary
Medial hypothalamic orexin neurons, not lateral ones, showed increased activation correlating with better performance on a Go/No-Go task. This suggests a specific role for medial orexin neurons in response inhibition and behavioral control.
Area of Science:
- Neuroscience
- Behavioral Neuroscience
Background:
- Orexin neurons (Orx), also known as hypocretin neurons, are located in the hypothalamus and project throughout the central nervous system (CNS).
- The orexin system is implicated in various functions, including stress, reward, wakefulness, and feeding behavior.
- Previous research suggests a functional division, with medial hypothalamic orexin neurons (dorsomedial hypothalamus [DMH] and perifornical area [PFA]) involved in stress and arousal, and lateral hypothalamic (LH) orexin neurons in reward processes.
Purpose of the Study:
- To investigate the differential roles of medial (DMH/PFA) versus lateral (LH) hypothalamic orexin neurons in a Go/No-Go task.
- To determine if orexin neuron activation correlates with performance on a task involving behavioral inhibition and reward.
Main Methods:
- Compared Fos activation (a marker of neuronal activity) in medial and lateral hypothalamic orexin neurons.
- Utilized a Go/No-Go behavioral paradigm involving a palatable food reward.
- Correlated Fos activation levels with task accuracy.
Main Results:
- Increased Fos activation in medial hypothalamic orexin neurons was significantly correlated with higher accuracy on the Go/No-Go task.
- No significant correlation was observed between Go/No-Go task accuracy and activation of lateral hypothalamic orexin neurons.
- These findings support a functional segregation between medial and lateral orexin neuron populations.
Conclusions:
- Medial hypothalamic orexin neurons play a crucial role in behavioral inhibition and task performance requiring response control.
- The study highlights a functional dichotomy within the orexin system, differentiating the roles of medial and lateral neuronal populations.
- Orexin neurons in the medial hypothalamus are specifically involved in cognitive processes related to inhibitory control.
Related Concept Videos
01:37Hypothalamic-Pituitary Axis
66.2K
The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. The HPA axis is part of the neuroendocrine system because it involves both neuronal and hormonal communication. Its function is to regulate homeostatic systems—metabolic, cardiovascular, and immune—providing the necessary means to respond to a stressor.
66.2K
02:04Co-activators and Co-repressors
8.7K
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
8.7K
02:26tRNA Activation
23.0K
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
23.0K
01:26Activation Energy
86.7K
Activation energy is the minimum amount of energy necessary for a chemical reaction to move forward. The higher the activation energy, the slower the rate of the reaction. However, adding heat to the reaction will increase the rate, since it causes molecules to move faster and increase the likelihood that molecules will collide. The collision and breaking of bonds represents the uphill phase of a reaction and generates the transition state. The transition state is an unstable high-energy state...
86.7K
02:42Eukaryotic Transcription Activators
12.8K
Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD.
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These...
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These...
12.8K
01:55Secondary Active Transport
138.0K
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
138.0K