Magnetic resonance imaging assessment of the lateral geniculate nucleus volume and height in patients with glaucoma:a Meta-analysis

AIM:To evaluate the lateral geniculate nucleus(LGN)volume and height using magnetic resonance imaging(MRI)in glaucoma patients.METHODS:Literatures retrieval was carried out through Pub Med,Web of Science,Embase,and Cochrane Library.Studies that compared the volume and height of LGN in glaucoma patients with that in control subjects were included.The volume and height of LGN were extracted from the included studies.The Review Manager 5.4.1 software was used for the Meta-analysis.RESULTS:This Meta-analysis included 10 crosssectional studies,including the eyes of 223 glaucoma patients and 185 healthy controls.Compared with the control subjects,the volume and height of LGN in glaucoma patients measured by MRI were significantly reduced{-29.13 mm3,95%[confidence interval(CI):-44.82 to-13.43,P=0.0003;-0.61 mm,95%CI:-0.78 to-0.44,P<0.00001,respectively]}.Subgroup analysis demonstrated that the differences of LGN volume and height between glaucoma patients and control subjects in the older group were smaller than that in the younger group,and LGN volume decreased with the increase of glaucoma severity.CONCLUSION:The results demonstrate that the volume and height of LGN are decreased in glaucoma patients,and LGN volume can be considered a parameter of glaucoma severity.

Time-dependent changes in eye-specific segregation in the dorsal lateral geniculate nucleus and superior colliculus of postnatal mice

Eye-specific segregation in the dorsal lateral geniculate nucleus(dLGN) and superior colliculus(SC) starts from the embryonic stage and continues to develop postnatally until eye-opening in mice. However, there have been few systematic studies on the details of this developmental process. Here, we carried out time-dependent studies of eye-specific segregation in the dLGN and SC. Our results demonstrated that the development of eye-specific segregation in the SC is completed before postnatal day 12(P12), which is earlier than in the dLGN(P20). During the whole period, ipsilateral and overlapping axonal projections decreased continuously in both the dLGN and SC. On the other hand, contralateral axonal projections showed little change, except for a slight decrease between P8 and P20 in the dLGN.

Kinetics of low threshold calcium channels of relay cells in cat lateral geniculate nucleus

Kinetics of the low threshold T-type Ca2+ channel is studied with single electrode voltage damp technique on brain slices of the cat lateral geniculate nucleus (LGN). Space damp is dramatically improved by blocking various K+ and Na+ channels, decreasing Ca2+ current and selecting proper holding potentials. Results from this study are similar to those obtained from acutely dissociated LGN neurons of the rat, indicating that the kinetics of T-Ca2+ channels of the cat LGN neurons is the same as that of the rat LGN. The result reported previously on the cat LGN may result from a defect in space damp.

A new anterograde trans-synaptic tracer based on Sindbis virus

Mapping neural circuits is critical for understanding the structure and function of the nervous system.Engineered viruses are a valuable tool for tracing neural circuits.However,current tracers do not fully meet the needs for this approach because of various drawbacks,such as toxicity and characteristics that are difficult to modify.Therefore,there is an urgent need to develop a new tracer with low toxicity and that allows for long-term studies.In this study,we constructed an engineered Sindbis virus(SINV)expressing enhanced green fluorescent protein(EGFP)reporter gene(SINV-EGFP)and found that it had no significant difference in biological characterization compared with the wild-type Sindbis virus in BHK-21 cells and neurons in vitro.We injected the virus into the visual circuit of mouse brain and found that the virus infected neurons in the local injected site and anterogradely spread in the neural circuits.Although the efficiency of transmission was limited,the findings demonstrate that SINV can be used as a new anterograde tracer to map neural circuits in mouse brain and that it spreads exclusively in the anterograde direction.Further,use of SINV in mouse brain research will provide longer time windows for circuit tracing than is possible with herpes simplex virus and vesicular stomatitis virus tracers.