Using rlbp1a and rlbp1b single and double mutants, we investigated the pathological effects on visual function. Our analyses revealed that rlbp1a was essential for cone photoreceptor function and chromophore metabolism in the fish eyes. They accumulated cis and all- trans -retinyl esters which displayed as enlarged lipid droplets in the RPE reminiscent of the subretinal yellow-white lesions in patients with RLBP1 mutations. During aging, these fish developed retinal thinning and cone and rod photoreceptor dystrophy.
In contrast, rlbp1b mutants did not display impaired vision. The double mutant essentially replicated the phenotype of the rlbp1a single mutant. Together, our study showed that the rlbp1a zebrafish mutant recapitulated many features of human blinding diseases caused by RLBP1 mutations and provided novel insights into the pathways for chromophore regeneration of cone photoreceptors. Cited 2 Views 7, Annotations Open annotations.
The current annotation count on this page is being calculated. Cite this article as: eLife ;8:e doi: Figure 1. Download asset Open asset. Dow RS The fiber connections of the posterior parts of the cerebellum in the rat and cat The Journal of Comparative Neurology 63 — Ito M Cerebellar circuitry as a neuronal machine Progress in Neurobiology 78 — Maklad A Fritzsch B Development of vestibular afferent projections into the hindbrain and their central targets Brain Research Bulletin 60 — The lumbar section of the spine is in the lower part of the back.
Nerve impulses to and from this section control hip and leg movements and bladder and bowel function. Finally, at the very bottom of the backbone are the sacrum, a large triangular bone at the base of the spine, and the coccyx, or tailbone. Nerve impulses to and from this section control balance, bladder and bowel function and sexual function.
Home Information and support Anatomy of the brain and spine. The brain The brain is a complex organ that is enclosed inside the skull. Anatomy of the brain Frontal lobe The frontal lobe governs our personality, character and behaviour. Occipital lobe The occipital lobe receives messages from the eyes and recognises shapes, colours and objects.
Parietal lobe The parietal lobe gives you a sense of 'me'. Temporal lobe You have two temporal lobes, one behind each ear. Cerebellum The cerebellum sits at the back of the brain and controls your sense of balance. Brain stem The brain stem controls your lungs and heart and blood pressure. Ventricles The ventricles make the cerebrospinal fluid CSF that protect and cushion the brain and spinal cord.
Thalamus There are lots of interesting things that go on in the very middle of the brain, which is made of smaller parts known as the limbic system. The nervous system The brain is connected to the rest of the body via the spinal cord and the nerves.
The central nervous system Together, the brain and spinal cord make up the central nervous system. The peripheral nervous system Nerves branch out from the spinal cord through the dura and vertebrae and become part of the peripheral nervous system.
With any movement of the legs, arms, and other body parts, sensory receptors respond by sending impulses to the brain. Along with other information, these stretch and pressure cues help our brain determine where our body is in space.
The sensory impulses originating in the neck and ankles are especially important. Proprioceptive cues from the neck indicate the direction in which the head is turned. Sensory information about motion, equilibrium, and spatial orientation is provided by the vestibular apparatus, which in each ear includes the utricle, saccule, and three semicircular canals. The utricle and saccule detect gravity information in a vertical orientation and linear movement.
The semicircular canals, which detect rotational movement, are located at right angles to each other and are filled with a fluid called endolymph. The receptor then sends impulses to the brain about movement from the specific canal that is stimulated.
When the vestibular organs on both sides of the head are functioning properly, they send symmetrical impulses to the brain.
Impulses originating from the right side are consistent with impulses originating from the left side. Balance information provided by the peripheral sensory organs—eyes, muscles and joints, and the two sides of the vestibular system—is sent to the brain stem.
There, it is sorted out and integrated with learned information contributed by the cerebellum the coordination center of the brain and the cerebral cortex the thinking and memory center. The cerebellum provides information about automatic movements that have been learned through repeated exposure to certain motions. For example, by repeatedly practicing serving a ball, a tennis player learns to optimize balance control during that movement.
Contributions from the cerebral cortex include previously learned information; for example, because icy sidewalks are slippery, one is required to use a different pattern of movement in order to safely navigate them. A person can become disoriented if the sensory input received from his or her eyes, muscles and joints, or vestibular organs sources conflicts with one another.
For example, this may occur when a person is standing next to a bus that is pulling away from the curb. The visual image of the large rolling bus may create an illusion for the pedestrian that he or she—rather than the bus—is moving.
However, at the same time the proprioceptive information from his muscles and joints indicates that he is not actually moving. Sensory information provided by the vestibular organs may help override this sensory conflict. In addition, higher level thinking and memory might compel the person to glance away from the moving bus to look down in order to seek visual confirmation that his body is not moving relative to the pavement.
As sensory integration takes place, the brain stem transmits impulses to the muscles that control movements of the eyes, head and neck, trunk, and legs, thus allowing a person to both maintain balance and have clear vision while moving. Gray and white matter are two different regions of the central nervous system. In the brain, gray matter refers to the darker, outer portion, while white matter describes the lighter, inner section underneath.
In the spinal cord, this order is reversed: The white matter is on the outside, and the gray matter sits within. Gray matter is primarily composed of neuron somas the round central cell bodies , and white matter is mostly made of axons the long stems that connects neurons together wrapped in myelin a protective coating.
The different composition of neuron parts is why the two appear as separate shades on certain scans. Each region serves a different role. Gray matter is primarily responsible for processing and interpreting information, while white matter transmits that information to other parts of the nervous system. The brain sends and receives chemical and electrical signals throughout the body. Different signals control different processes, and your brain interprets each.
Some make you feel tired, for example, while others make you feel pain. To do this, the central nervous system relies on billions of neurons nerve cells. The cerebrum front of brain comprises gray matter the cerebral cortex and white matter at its center.
The largest part of the brain, the cerebrum initiates and coordinates movement and regulates temperature. Other areas of the cerebrum enable speech, judgment, thinking and reasoning, problem-solving, emotions and learning. Other functions relate to vision, hearing, touch and other senses. The cerebral cortex is divided into two halves, or hemispheres.
It is covered with ridges gyri and folds sulci. The two halves join at a large, deep sulcus the interhemispheric fissure, AKA the medial longitudinal fissure that runs from the front of the head to the back.
The right hemisphere controls the left side of the body, and the left half controls the right side of the body. The two halves communicate with one another through a large, C-shaped structure of white matter and nerve pathways called the corpus callosum.
The corpus callosum is in the center of the cerebrum. The brainstem middle of brain connects the cerebrum with the spinal cord. The brainstem includes the midbrain, the pons and the medulla. The spinal cord extends from the bottom of the medulla and through a large opening in the bottom of the skull.
Supported by the vertebrae, the spinal cord carries messages to and from the brain and the rest of the body. Like the cerebral cortex, it has two hemispheres. The outer portion contains neurons, and the inner area communicates with the cerebral cortex.
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