Analyzing the role of extracellular matrix during nervous system development to advance new regenerative strategies

Regeneration in the central nervous system （CNS） is limited, and CNS damage often leads to cognitive impairment or permanent functional motor and sensory loss. Impaired regenerative capacity is multifactorial and includes inflammation, loss of the blood-brain barrier, and alteration in the extracellular matrix （ECM）. One of the main problems is the formation of a glial scar and the production of inhibitory ECM, such as proteoglycans, that generates a physical and mechanical barrier, impeding axonal regrowth （Figure 1A）.

Neurotrophic factors: from neurodevelopmental regulators to novel therapies for Parkinson's disease

Neuroprotection and neuroregeneration are two of the most promising disease-modifying ther- apies for the incurable and widespread Parkinson＇s disease. In Parkinson＇s disease, progressive degeneration of nigrostriatal dopaminergic neurons causes debilitating motor symptoms. Neurotrophic factors play important regulatory roles in the development, survival and maintenance of specific neuronal populations. These factors have the potential to slow down, halt or reverse the loss of nigrostriatal dopaminergic neurons in Parkinsoffs disease. Several neurotrophic fac- tors have been investigated in this regard. This review article discusses the neurodevelopmental roles and therapeutic potential of three dopaminergic neurotrophic factors： glial cell line-derived neurotrophic factor, neurturin and growth/differentiation factor 5.

Effect of Reelin signaling on pre-plate splitting during cerebral cortex development

The development of the 6-layered cerebral neocortex is one of the most important events during nervous system development, and disturbances could result in various malformations, causing clinically intractable diseases, such as epilepsy and cerebral palsy. Pre-plate splitting is the first developmental step of the cortical plate formation. Without correct pre-plate splitting, normal cerebral cortex structures are disturbed. The Reelin-Dabl molecular pathway plays a critical role during cerebral cortex development, and deficiencies in this pathway result in failed pre-plate splitting and an inverted cortical plate. This paper summarizes findings involving Reelin and pre-plate splitting and further explores the precise role of Reelin during pre-plate splitting.

Embracing oligodendrocyte diversity in the context of perinatal injury

Emerging evidence is fueling a new appreciation of oligodendrocyte diversity that is overturning the traditional view that oligodendrocytes are a homogenous cell population.Oligodendrocytes of distinct origins,maturational stages,and regional locations may differ in their functional capacity or susceptibility to injury.One of the most unique qualities of the oligodendrocyte is its ability to produce myelin.Myelin abnormalities have been ascribed to a remarkable array of perinatal brain injuries,with concomitant oligodendrocyte dysregulation.Within this review,we discuss new insights into the diversity of the oligodendrocyte lineage and highlight their relevance in paradigms of perinatal brain injury.Future therapeutic development will be informed by comprehensive knowledge of oligodendrocyte pathophysiology that considers the particular facets of heterogeneity that this lineage exhibits.

N-cadherin expression in the midbrain substantia nigra of perinatal rats

BACKGROUND： Cellular adhesion molecule mediates the effects of glial cell line-derived neurotrophic factor in dopaminergic neurons during nervous system development. It is assumed that cellular adhesion molecule plays an important role in dopaminergic neuron development. OBJECTIVE： To investigate N-cadherin expression in the midbrain substantia nigra during rat development. DESIGN, TIME AND SETTING： The developmental biology, controlled study was performed at the Laboratory of Research Center of Neurobiology, Xuzhou Medical College, China from April to October 2007. MATERIALS： Sprague Dawley rats （embryonic days 16, 18, and 20, as well as postnatal days 1, 3, 7, 14, and 21） were selected for this study. N-cadherin antibody was purchased from Santa Cruz, USA. METHODS： N-cadherin expression in the midbrain substantia nigra of perinatal rats was detected using reverse transcription polymerase chain reaction, Western blot, and immunohistochemistry methods. N-cadherin-positive cells were counted. MAIN OUTCOME MEASURES： N-cadherin mRNA, protein, and positive cells in the rat midbrain substantia nigra were quantified. RESULTS： The results of reverse transcription polymerase chain reaction and Western blot demonstrated that altered N-cadherin mRNA levels were similar to protein levels in the midbrain substantia nigra. N-cadherin mRNA and protein expression was low in the midbrain substantia nigra of embryonic day 16 rats but gradually increased, and reached a peak at postnatal day 1. N-cadherin mRNA and protein levels were still high at postnatal days 3 and 7, but significantly decreased at postnatal day 14. There was no significant difference in N-cadherin mRNA and protein expression between postnatal days 14 and 21 （P 〉 0.05）. The immunohistochemistry results demonstrated that there was no significant difference in the quantity of N-cadherin-positive cells per area in rats from embryonic day 16 to postnatal day 7 （P 〉 0.05）. The quantity of N-cadherin-positive cells per area was significantly decreased in rats at postnatal day 14. There was no significant difference in the number of N-cadherin-positive cells per area between postnatal days 14 and 21 （P 〉 0.05）. CONCLUSION： N-cadherin expression was reduced during embryonic stages, but reached a peak at postnatal days 1-7, and then gradually decreased in the rat midbrain substantia nigra.

Characterization and expression analysis of sox3 in medaka gonads

Numerous studies have showed that sox3 is involved in neurogenesis and sex differentiation in vertebrates.However,the accurate expression pattern is still unclear in fish.In this study,medaka sox3 was isolated and its expression patterns were compared with germ cell gene vasa in adult gonads.By reverse transcription-polymerase chain reaction(RT-PCR)analysis,sox3 RNA expression was detected in the brain,eyes and gonads.By chromogenic and fluorescent in situ hybridization,sox3 was present in the oogonia and early stages of oocytes as well as granulosa cells and theca cells in the later stages;in the testis,sox3 was occurred in the Sertoli cells and sperm with a specific signal in the location of chromatid body of sperm;in the embryos,sox3 was expressed in the central nervous.These results suggest that medaka sox3 gene was occurred in somatic and germ cells in adult gonads of both sexes,involved in the process of spermatogenesis,as well as the development of the nervous system.This study provides a precise expression pattern of sox3 and suggests that sox3 may be involved in gonadal and nervous system development of fish.