Related Experiment Video
Updated: Jul 18, 2026
05:54
Transplantation into the Anterior Chamber of the Eye for Longitudinal, Non-invasive In vivo Imaging with Single-cell Resolution in Real-time
Published on: March 10, 2013
Early development of ocular dominance columns.
1Howard Hughes Medical Institute and Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA. jcrowley@neuro.duke.edu
Science (New York, N.Y.)
|November 18, 2000
Summary
Early ocular dominance columns in ferrets form independently of retinal activity. This suggests distinct mechanisms for initial column development versus later activity-dependent refinement in the visual cortex.
Area of Science:
- Neuroscience
- Developmental Neuroscience
- Visual System Development
Background:
- Ocular dominance columns (ODCs) in the visual cortex are crucial for binocular vision.
- Their formation is traditionally thought to depend on prolonged, activity-dependent processes.
- Early development and the precise mechanisms of ODC formation remain incompletely understood.
Purpose of the Study:
- To investigate the early formation mechanisms of ocular dominance columns in the ferret visual cortex.
- To determine the role of retinal activity in the initial segregation of lateral geniculate nucleus (LGN) axons.
- To differentiate between mechanisms of initial ODC formation and later activity-dependent plasticity.
Main Methods:
- Direct injection of tracers into the lateral geniculate nucleus (LGN) of early postnatal ferrets.
- Visualization and analysis of LGN axon targeting and segregation in cortical layer 4.
- Experimentally inducing imbalances in retinal activity to assess their impact on column formation.
Main Results:
- Segregated ocular dominance columns were observed in the LGN less than 7 days after layer 4 innervation.
- These early-formed columns were resistant to experimentally induced imbalances in retinal activity.
- This indicates that initial ODC formation is independent of visual activity.
Conclusions:
- Initial ocular dominance column formation does not rely on activity-dependent plasticity.
- Distinct axonal populations may target specific layer 4 locales for initial segregation.
- Separate mechanisms govern the initial establishment and subsequent refinement of ODCs during the critical period.
Related Concept Videos
01:25Glaucoma: Overview
Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal...
01:28Angle Closure Glaucoma: Treatment
Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor...
01:20Muscles of the Eye
The muscles of the eye are sophisticated structures that control eye movement and focus, allowing for the precise and rapid adjustments necessary for vision. The human eye is controlled by ten muscles — six extraocular muscles, three intraocular muscles, and one primary eyelid retractor muscle.
Extraocular Muscles
The six extraocular muscles surround the eyeball and control its movements. They are responsible for a wide range of eye motions, including looking up, down, left, right, and rotating...
Extraocular Muscles
The six extraocular muscles surround the eyeball and control its movements. They are responsible for a wide range of eye motions, including looking up, down, left, right, and rotating...
01:17Accessory Structures of the Eye
Optical perception, or vision, is an extraordinary sense dependent on converting light signals received via the ocular organs. These organs, known as eyes, are securely positioned within the bony cavities of the skull, called orbits. The orbits serve a dual purpose: a protective shield for the ocular globes and a stable attachment point for the soft ocular tissues. The eye's external protective mechanisms include the eyelids, which are edged with lashes that act as a barrier against foreign...
01:20Anatomy of the Eyeball
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle layer, the vascular tunic,...
01:16Focusing of Light in the Eye
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...