Dynamic expression of insulin￣like growth factor 2 during critical period of visual development in lateral geniculate body of mice / 解剖学报

Objective To detect the dynamic expression of insulin-like growth factor 2 (IGF2) in lateral geniculate body (LGB) during the critical period of visual development. Methods Three groups of Kunming mice of different ages were selected for testing, which were 3 weeks old, 5 weeks old and 7 weeks old, twelve in each group. The forepaw-reaching reflex test was used to detect whether the visual function of the mice was normal in each group. Immunohistochemical technique was used to detect the expression of IGF2 protein and its receptor in the lateral geniculate body of normal mice at week 3, 5 and 7 postnatal, and to analyze the expression of the protein of IGF2 and its receptor in each part of the lateral geniculate body. Results The expression of IGF2 protein in the dorsal lateral geniculate nucleus decreased significantly at week 5 postnatal and increased significantly at week 7 postnatal, and increased gradually over time at week 5 and week 7 postnatal in the ventral geniculate nucleus. The expression of IGF2 receptor protein in the dorsal lateral geniculate nucleus and ventral nucleus increased significantly at week 5 postnatal, and at week 7 postnatal, the expression of IGF2 receptor decreased to week 3 level in lateral geniculate body of mice. Conclusion The expression of IGF2 and its receptor in lateral geniculate body of mice during critical period of visual development changed dynamically, and the expression patterns of IGF2 and its receptor in different parts of LGB were not completely consistent. The expression of IGF2 and its receptors may be related to the plasticity of visual development in mice.

Avaliação da camada de fibras nervosas da retina nas afecções neuroftalmológicas da via óptica anterior / Retinal nerve fiber evaluation in neuro-ophthalmic diseases of the anterior visual pathway

A avaliação da camada de fibras nervosas da retina tem grande importância no diagnóstico e acompanhamento de várias afecções da via óptica anterior. Nesta revisão, discutiremos os principais métodos de análise clínica e instrumental da camada de fibras nervosas da retina e revisamos os principais achados encontrados nas afecções da via óptica anterior incluindo lesões inflamatórias, isquêmicas, tóxicas, hereditárias, compressivas e traumáticas do nervo óptico, as lesões do quiasma óptico, as do trato óptico e aquelas do corpo geniculado lateral.

Retinal nerve fiber evaluation is important in the diagnosis and management of several diseases of the anterior visual pathway. In this report we review the clinical findings and the current techonologies avalilable to analyse the retinal nerve fiber layer. We furthermore review the main findings in several disease of the anterior visual pathways including inflammatory, ischemic, toxics, hereditary, compressive and traumatic optic neuropathies as well as lesion of the optic chiasm, optic tract and lateral geniculate body.

Immunocytochemical Study on the Monoaminergic Innervation of Diencephalic Visual Structures in the Squirrel Monkey

This study was for investigating relations between distributions of monoamines-norepinephrine, serotonin, and dopamine-on the visual system and their functions. Distributions of these monoamines in the lateral geniculate body, pulvinar, lateral posterior nucleus, and suprachiasmatic nucleus were investigated. Brain of a squirrel monkey was removed and frozen sectioned. Immunocytochemical study was performed for the tissue of the brain. Results showed that the anterior part of the lateral geniculate body contained more monoamines than the posterior part. More serotonins were distrbuted at the magnocellular part, and more dopamines were found at the parvocellular part. In pulvinar, more norepinephrines were distributed at the medial part, while serotonins were evenly distributed at all parts. In lateral posterior nucleus and suprachiasmatic nucleus, three kinds of monoamines were distributed with high density. Among the three, density of the serotonin showed the highest value. The lateral geniculate body relates with visual perception such as visual acuity, form and color perception, and stereopsis, while the pulvinar relates with visual functions, such as visual attention, sensory integration, and differentiation. Since norepinephrine and serotonine are distributed with high density in the pulvinar than in the lateral geniculate body those two monoamines are expected to playa major role for visual functions. Inferior part of the pulvinar relates with visual imagination, and the lateral posterior nucleus relates with integration of visual sensory. Relatively high distribution of dopamine in these two parts means that dopamine may playa major role for visual imagination and integration. As suprachiasmatic nucleus relates with controlling biorhythm, dense distribution of monoamines in suprachiasmatic nucleus implies that the monoamines may work for controlling biorhythm.

CONNECTION BETWEEN THE SUPERIORCOLLICULUS AND LATERAL GENICULATE BODY IN THE GOLDEN HAMSTER / 解剖学报

Connection between the superior colliculus(SC)and the dorsal and ventral lateral geniculate nuclei (LGd and LGv) were studied in adult golden hamsters using anterograde and retrograde pathway tracing methods 1. In four hamsters, the cytoarchitecture of the SC, LGd and LGv was examined in brain sections stained with Nissl's or Loyez's method. 2. A single injection of a mixture of ~3H-leucine and ~3H-proline was made into various regions of the SC in each of 4 animals (1 day survival) for studying the pattern of terminal distribution of the projections from the SC to the ipsilateral LGd and LGv. In animals where the injection site was located in the superficial gray layers of the lateral portion of the SC, labelled terminals were found in the caudal lateral part of the LGd and LGv. In the case where the injection was restricted in more medial part of the SC, the terminal labelling was observed in the rostral lateral portion of the lateral geniculate nuclei. 3. One day after an injection of horseradish peroxidase (HRP) into the LGd (4 animals), LGv(2 animals), or LP(2 animals) labelled neurons were observed in the superficial gray layers of the ipsilateral superior colliculus. No HRP-labelled neuron was detected in deeper laminae in the colliculus. These results indicate that neurons in the superficial gray layers of the SC project to the ipsilateral LGd and LGv, and the projections are organized topogra- phically according to the retinotopic or visual field map