Morphological disruption and visual tuning alterations in the primary visual cortex in glaucoma(DBA/2J)mice

Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the primary visual cortex(V1)is altered in glaucoma.This study used DBA/2J mice as a model for spontaneous secondary glaucoma.The aim of the study was to compare the electrophysiological and histomorphological chara cteristics of neurons in the V1between 9-month-old DBA/2J mice and age-matched C57BL/6J mice.We conducted single-unit recordings in the V1 of light-anesthetized mice to measure the visually induced responses,including single-unit spiking and gamma band oscillations.The morphology of layerⅡ/Ⅲneurons was determined by neuronal nuclear antigen staining and Nissl staining of brain tissue sections.Eighty-seven neurons from eight DBA/2J mice and eighty-one neurons from eight C57BL/6J mice were examined.Compared with the C57BL/6J group,V1 neurons in the DBA/2J group exhibited weaker visual tuning and impaired spatial summation.Moreove r,fewer neuro ns were observed in the V1 of DBA/2J mice compared with C57BL/6J mice.These findings suggest that DBA/2J mice have fewer neurons in the VI compared with C57BL/6J mice,and that these neurons have impaired visual tuning.Our findings provide a better understanding of the pathological changes that occur in V1 neuron function and morphology in the DBA/2J mouse model.This study might offer some innovative perspectives regarding the treatment of glaucoma.

A novel 2.95–3.65 GHz CMOS LC-VCO using tuning curve compensation

This paper presents a new CMOS LC-VCO with a 2.95–3.65 GHz tuning range.The large tuning range is achieved by tuning curve compensation using a novel varactor configuration,which is mainly composed of four accumulation-mode MOS varactors（A-MOS）and two bias voltages.The proposed varactor has the advantages of optimizing quality factor and tuning range simultaneously,linearizing the effective capacitance and thus greatly reducing the amplitude-to-phase modulation（AM-PM）conversion.The circuit is validated by simulations and fabricated in a standard 0.18μm 1P6M CMOS process.Measured phase noise is lower than–91 dBc at 100 kHz offset from a 3.15 GHz carrier while measured tuning range is 21.5%as the control voltage varies from 0 to 1.8 V.The VCO including buffers consumes 2.8 mA current from a 1.8 V supply.

An Accurate 1.08GHz CMOS LC Voltage-Controlled Oscillator

An accurate 1.08GHz CMOS LC voltage-controlled oscillator is implemented in a 0.35μm standard 2P4M CMOS process.A new convenient method of calculating oscillator period is presented.With this period calculation technique,the frequency tuning curves agree well with the experiment.At a 3.3V supply,the LC-VCO measures a phase noise of -82.2dBc/Hz at a 10kHz frequency offset while dissipating 3.1mA current.The chip size is 0.86mm×0.82mm.