Related Experiment Video
Updated: May 7, 2026
05:21
Whole Mount Immunolabeling of Olfactory Receptor Neurons in the Drosophila Antenna
Published on: May 4, 2014
Olfactory imprinting is triggered by MHC peptide ligands
Cornelia Hinz1, Iori Namekawa, Ri Namekawa
1Department of Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, Carl von Ossietzky Str. 9-11, 26111 Oldenburg, Germany.
Scientific Reports
|October 1, 2013
Summary
Scientists discovered that Major Histocompatibility Complex (MHC) peptides act as natural chemical signals for olfactory imprinting in zebrafish. These peptides enable lifelong memory for kin recognition, crucial for homing behaviors in various species.
Area of Science:
- Neuroscience
- Chemical Ecology
- Ethology
Background:
- Olfactory imprinting is a vital form of lifelong memory enabling animals like salmon and coral reef fish to return to natal sites.
- The specific natural chemicals responsible for this imprinting have remained unidentified until now.
Purpose of the Study:
- To identify the natural chemical cues involved in olfactory imprinting and kin recognition in zebrafish.
- To investigate the role of Major Histocompatibility Complex (MHC) peptides in olfactory imprinting.
Main Methods:
- Zebrafish were exposed to synthetic MHC peptides.
- In vivo calcium imaging was used to monitor neural activity in the olfactory bulb.
- Behavioral assays assessed kin recognition.
Main Results:
- MHC peptides, specifically nine-amino acid sequences, were found to elicit olfactory imprinting and kin recognition in a genotype-dependent manner.
- Olfactory bulb neurons demonstrated high sensitivity to MHC peptides, with detection thresholds as low as 1 pM.
- Neural responses to MHC peptides overlapped with responses to kin odor but not food odor.
Conclusions:
- MHC peptides function as potent natural olfactory stimuli and chemical signals for imprinting in zebrafish.
- This finding supports the hypothesis that MHC peptides mediate kin recognition and homing behaviors through olfactory imprinting.
Related Concept Videos
01:25Olfaction
The sense of smell is achieved through the activities of the olfactory system. It starts when an airborne odorant enters the nasal cavity and reaches olfactory epithelium (OE). The OE is protected by a thin layer of mucus, which also serves the purpose of dissolving more complex compounds into simpler chemical odorants. The size of the OE and the density of sensory neurons varies among species; in humans, the OE is only about 9-10 cm2.
The olfactory receptors are embedded in the cilia of the...
The olfactory receptors are embedded in the cilia of the...
01:31Antigen Processing Pathways
MHC molecules are key players in the immune response, enabling T cells to recognize and respond to specific antigens. They are present on the surface of all nucleated cells in the body and are instrumental in presenting antigens to T cells and activating them. T cells recognize the MHC-antigen complex and initiate an immune response. MHC class I and MHC class II are two main types of MHC molecules, each associated with a distinct antigen processing pathway.
MHC Class I: Presenting Endogenous...
MHC Class I: Presenting Endogenous...
01:22Imprinting
Behavioral imprinting is observed in some newborn animals and occurs when they develop strong and specific attachments to another animal (usually a parent) following brief, early-life exposures. Offspring imprint onto parents within a brief period after birth or hatching; this time window is called the critical period. Once imprinting occurs, the bond established between the parents and their offspring is usually long-lasting.
01:20Physiology of Smell and Olfactory Pathway
Humans detect odors with the help of specialized cells located in the upper part of the nasal cavity, called olfactory receptor neurons (ORNs). ORNs possess hair-like structures called cilia, which are receptive to sensations from the inhaled air. When an odorant molecule binds to a specific receptor on the cell of the cilia, it leads to a series of events that ultimately cause the ORN to send electrical signals to the olfactory bulb in the brain through the olfactory nerves.
The olfactory...
The olfactory...
01:26Antigens Involved in Adaptive Immunity
An antigen is any substance the immune system identifies as foreign and potentially harmful to the body, prompting an immune response. Antigens have two functional properties: immunogenicity and reactivity. Immunogenicity is the ability of an antigen to stimulate a specific immune response. At the same time, reactivity describes the antigen's ability to react with the cells and antibodies produced in response to it.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
01:03Olfactory Receptors: Location and Structure
The process of olfaction, also known as the sense of smell, is a sophisticated chemical response system. The specialized sensory neurons that facilitate this process, known as olfactory receptor neurons, are situated in an upper segment of the nasal cavity, known as the olfactory epithelium. Olfactory sensory neurons are bipolar, with their dendrites extending from the epithelium's apex into the mucus that lines the nasal cavity. Airborne molecules, when inhaled, traverse the olfactory...