Related Experiment Video
Updated: Jul 11, 2026
08:28
Visualization of Tangential Cell Migration in the Developing Chick Optic Tectum
Published on: October 24, 2018
A visual pathway links brain structures active during magnetic compass orientation in migratory birds
Dominik Heyers1, Martina Manns, Harald Luksch
1AG Neurosensorik, Institute of Biology, University of Oldenburg, Oldenburg, Germany. dominik.heyers@uni-oldenburg.de
Plos One
|September 27, 2007
Summary
Migratory birds use a light-dependent magnetic compass. This study reveals a visual pathway connecting retinal cryptochrome neurons to Cluster N, supporting the idea that birds "see" the geomagnetic field.
Area of Science:
- Ornithology
- Neuroscience
- Sensory Biology
Background:
- Migratory birds' magnetic compass is thought to be light-dependent.
- High neuronal activity in retinal cryptochrome neurons and forebrain Cluster N occurs during magnetic orientation.
Purpose of the Study:
- To investigate the functional neuronal connection between retinal neurons and Cluster N.
- To determine if these active brain areas are part of a visual processing stream.
Main Methods:
- Neuronal tracing combined with behavioral experiments.
- Measuring sensory-driven gene expression (ZENK) as a marker for neuronal activity during magnetic orientation.
Main Results:
- A functional neuronal connection was demonstrated between retinal neurons and Cluster N via the visual thalamus.
- Cluster N appears to be a specialized region within the visual wulst.
- The active neural areas are part of the ascending thalamofugal visual pathway.
Conclusions:
- Migratory birds likely use their visual system to perceive the geomagnetic field's direction.
- These findings support the hypothesis that birds visually sense the Earth's magnetic field for navigation.
Related Concept Videos
01:24Vision
Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed.
01:26Visual System
Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision.
Once through the pupil, the light passes through the lens, a...
Once through the pupil, the light passes through the lens, a...
01:22Photoreceptors and Visual Pathways
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category, whereas...
00:53Migration
Migration is long-range, seasonal movement from one region or habitat to another. This common strategy, carried out by many different organisms around the world, is an adaptive response that typically corresponds to changes in an organism’s environment, like resource availability or climate. Migrations can involve huge groups of thousands of animals as well as single individuals traveling alone and can range from thousands of kilometers to just a few hundred meters.
01:15Auditory Pathway
Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea.
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the...
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the...
01:28Major Somatic Sensory Pathways
Sensory impulses related to touch, pressure, vibration, and proprioception from various body parts, such as the limbs, trunk, neck, and posterior head, travel to the cerebral cortex through the posterior column-medial lemniscus pathway. The pathway’s name derives from the two white-matter tracts that convey the impulses: the spinal cord's posterior column and the brainstem's medial lemniscus. First-order sensory neurons extend their axons into the spinal cord, forming the posterior columns...