BDNF improves axon transportation and rescues visual function in a rodent model of acute elevation of intraocular pressure.

Optic neuropathies lead to blindness; the common pathology is the degeneration of axons of the retinal ganglion cells. In this study, we used a rat model of retinal ischemia-reperfusion and a one-time intravitreal brain-derived neurotrophic factor (BDNF) injection; then we examined axon transportation function, continuity, physical presence of axons in different part of the optic nerve, and the expression level of proteins involved in axon transportation. We found that in the disease model, axon transportation was the most severely affected, followed by axon continuity, then the number of axons in the distal and proximal optic nerve.

Decreasing intraocular pressure significantly improves retinal vessel density, cytoarchitecture and visual function in rodent oxygen induced retinopathy.

We attempted to explore a noninvasive, easily applicable and economically affordable therapy for retinopathy of prematurity (ROP). Rat pups were raised in 80% oxygen from postnatal day 7 to P12, and returned to room air. Travoprost eye drops were administered twice a day for 7 days, to reduce intraocular pressure (IOP) by about 20%.

Long-lasting impairments in rodent oxygen-induced retinopathy measured by retinal vessel density and visual function.

In mild or moderate retinopathy of prematurity (ROP), retinal vessels undergo obliteration, proliferation, and regression. Despite complete regression of vessel abnormalities, a variety of visual impairments have been reported. Rodent oxygen-induced retinopathy (OIR) is widely used as a model to study ROP.

Different functional susceptibilities of mouse retinal ganglion cell subtypes to optic nerve crush injury.

In optic neuropathies, the progressive deterioration of retinal ganglion cell (RGC) function leads to irreversible vision loss. Increasing experimental evidence suggests differing susceptibility for RGC functional subtypes. Here with multi-electrode array recordings, RGC functional loss was characterized at multiple time points in a mouse model of optic nerve crush.

Temporal properties of dual-peak responses of mouse retinal ganglion cells and effects of inhibitory pathways.

Dual-peak responses of retinal ganglion cells (RGCs) are observed in various species, previous researches suggested that both response peaks were involved in retinal information coding. In the present study, we investigated the temporal properties of the dual-peak responses recorded in mouse RGCs elicited by spatially homogeneous light flashes and the effect of the inhibitory inputs mediated by GABAergic and/or glycinergic pathways. We found that the two peaks in the dual-peak responses exhibited distinct temporal dynamics, similar to that of short-latency and long-latency single-peak responses respectively.

Overexpression of Wnt5a in mouse epidermis causes no psoriasis phenotype but an impairment of hair follicle anagen development.

Increased Wnt5a expression has been observed in psoriatic plaques. However, whether Wnt5a overexpression directly causes psoriasis is unknown. In this study, we generated transgenic (TG) mice with epidermal Wnt5a overexpression under the control of the human K14 promoter.

Constitutive activation of ectodermal β-catenin induces ectopic outgrowths at various positions in mouse embryo and affects abdominal ventral body wall closure.

Vertebrate limbs originate from the lateral plate mesoderm (LPM) and the overlying ectoderm. While normal limb formation in defined regions has been well studied, the question of whether other positions retain limb-forming potential has not been fully investigated in mice. By ectopically activating β-catenin in the ectoderm with Msx2-cre, we observed that local tissue outgrowths were induced, which either progressed into limb-like structure within the inter-limb flank or formed extra tissues in other parts of the mouse embryo.

Drug addiction is associated with leukocyte telomere length.

Telomeres are protective chromosomal structures that play a key role in preserving genomic stability. Telomere length is known to be associated with ageing and age-related diseases. To study the impairment of telomeres induced by drug abuse, we conducted an association study in the Chinese Han population.

Long-term rescue of rat retinal ganglion cells and visual function by AAV-mediated BDNF expression after acute elevation of intraocular pressure.

Purpose: To evaluate the ability of increased expression of brain-derived neurotrophic factor (BDNF) using adenoassociated viral (AAV) vector to prevent the loss of rat retinal ganglion cells (RGCs) and visual function after acute elevation of intraocular pressure (IOP).

Methods: AAV vectors (expressing BDNF or GFP) were injected into the vitreous 6 hours after a transient IOP elevation to 130 mm Hg for 45 minutes. Protective effects were evaluated by counting RGCs retrogradely labeled with fluorogold (FG) from the superior colliculus, measuring the amplitude and the latency of the P1 component of the visual evoked potential (VEP), and observing the visual acuity and contrast sensitivity in awake and behaving animals.

Direct reprogramming of Sertoli cells into multipotent neural stem cells by defined factors.

Multipotent neural stem/progenitor cells hold great promise for cell therapy. The reprogramming of fibroblasts to induced pluripotent stem cells as well as mature neurons suggests a possibility to convert a terminally differentiated somatic cell into a multipotent state without first establishing pluripotency. Here, we demonstrate that Sertoli cells derived from mesoderm can be directly converted into a multipotent state that possesses neural stem/progenitor cell properties.

Direction-selective circuitry in rat retina develops independently of GABAergic, cholinergic and action potential activity.

The ON-OFF direction selective ganglion cells (DSGCs) in the mammalian retina code image motion by responding much more strongly to movement in one direction. They do so by receiving inhibitory inputs selectively from a particular sector of processes of the overlapping starburst amacrine cells, a type of retinal interneuron. The mechanisms of establishment and regulation of this selective connection are unknown.

Tracer coupling of intrinsically photosensitive retinal ganglion cells to amacrine cells in the mouse retina.

Intrinsically photosensitive retinal ganglion cells (ipRGCs) are a subtype of ganglion cell in the mammalian retina that expresses the photopigment melanopsin and drives non-image-forming visual functions. Three morphological subtypes of ipRGCs (M1, M2, and M3) have been described based on their dendritic stratifications in the inner plexiform layer (IPL), but the question of their potential interactions via electrical coupling remains unsettled. In this study, we have addressed this question in the mouse retina by, injecting the tracer Neurobiotin into ipRGCs that had been genetically labelled with the fluorescent protein, tdTomato.

Properties of mouse retinal ganglion cell dendritic growth during postnatal development.

The property of dendritic growth dynamics during development is a subject of intense interest. Here, we investigated the dendritic motility of retinal ganglion cells (RGCs) during different developmental stages, using ex vivo mouse retina explant culture, Semliki Forest Virus transfection and time-lapse observations. The results illustrated that during development, the dendritic motility underwent a change from rapid growth to a relatively stable state, i.

Changing dendritic field size of mouse retinal ganglion cells in early postnatal development.

During early postnatal development, dendrites of retinal ganglion cells (RGCs) extend and branch in the inner plexiform layer to establish the adult level of stratification, pattern of branching, and coverage. Many studies have described the branching patterns, transient features, and regulatory factors of stratification of the RGCs. The rate of RGC dendritic field (DF) expansion relative to the growing retina has not been systematically investigated.

Change detection by thalamic reticular neurons.

The thalamic reticular nucleus (TRN) is thought to function in the attentional searchlight. We analyzed the detection of deviant acoustic stimuli by TRN neurons and the consequences of deviance detection on the TRN target, the medial geniculate body (MGB) of the rat. TRN neurons responded more strongly to pure-tone stimuli presented as deviant stimuli (low appearance probability) than those presented as standard stimuli (high probability) (deviance-detection index = 0.

Slow recovery from excitation of thalamic reticular nucleus neurons.

Responses to repeated auditory stimuli were examined in 103 neurons in the auditory region of the thalamic reticular nucleus (TRN) and in 20 medial geniculate (MGB) neurons of anesthetized rats. A further six TRN neurons were recorded from awake rats. The TRN neurons showed strong responses to the first trial and weak responses to the subsequent trials of repeated auditory stimuli and electrical stimulation of the MGB and auditory cortex when the interstimulus interval (ISI) was short (<3 s).

Alpha cells take off first.

Using a transgenic mouse line in which GFP is expressed in a single population of retinal ganglion cells (RGCs), Huberman and colleagues report in this issue of Neuron that the axon terminals of RGCs exhibit an orderly pattern of distribution in the higher visual centers. This pattern undergoes a developmental refinement, and synchronous activity in the retina regulates columnar but not laminar formation.

ON direction-selective ganglion cells in the mouse retina.

Two types of ganglion cells (RGCs) compute motion direction in the retina: the ON-OFF direction-selective ganglion cells (DSGCs) and the ON DSGCs. The ON DSGCs are much less studied mostly due to the low encounter rate. In this study, we investigated the physiology, dendritic morphology and synaptic inputs of the ON DSGCs in the mouse retina.

Lateral components in the cone terminals of the rabbit retina: horizontal cell origin and glutamate receptor expression.

We examined the identities of horizontal cell (HC) lateral components in cone terminals and the expression of glutamate receptors on the tips of HC dendrites. We injected A-type horizontal cells (AHCs) with neurobiotin and demonstrated that neurobiotin labeled completely all AHCs within a patch of retina. We converted neurobiotin by using diaminobenzidine and considered labeled processes to be from AHCs and unlabeled processes to be from B-type horizontal cells (BHCs).

Identification of ON-OFF direction-selective ganglion cells in the mouse retina.

We identified the ON-OFF direction-selective ganglion cells (DSGCs) in the mouse retina and characterized their physiological, morphological and pharmacological properties. These cells showed transient responses to the onset and termination of a stationary flashing spot, and strong directional selectivity to a moving rectangle. Application of various pharmacological reagents demonstrated that the ON-OFF DSGCs in the mouse retina utilize a similar array of transmitters and receptors to compute motion direction to their counterparts in the rabbit retina.

Development of the mouse retina: emerging morphological diversity of the ganglion cells.

The time course and regulatory mechanisms of dendritic development are subjects of intense interest. We approached these problems by investigating dendritic morphology of retinal ganglion cells (RGCs) at four early postnatal stages. The RGCs develop from a diffusely stratified and poorly differentiated group at birth (P0), to 16 distinct, morphologically well-defined subtypes before eye opening (P13).

Dendritic relationship between starburst amacrine cells and direction-selective ganglion cells in the rabbit retina.

We investigated the dendritic relationship between starburst amacrine cells (SAs) and morphologically and physiologically characterized ON and ON-OFF direction-selective ganglion cells (DSGCs) in the rabbit retina. ON and ON-OFF DSGCs were found to exhibit tight dendritic cofasciculation with the SA plexus, visualized by immunolabelling of the vesicular acetylcholine transporter (VAChT). The degree of cofasciculation of both types of DSGC dendrites and SA plexus was found to be significant, unlike the relationship between non-DS cells and the SA plexus, which was close to chance distribution.