Delayed improvements in visual memory task performance among chronic schizophrenia patients after high-frequency repetitive transcranial magnetic stimulation

BACKGROUND Cognitive impairments are core characteristics of schizophrenia,but are largely resistant to current treatments.Several recent studies have shown that highfrequency repetitive transcranial magnetic stimulation(rTMS)of the left dorsolateral prefrontal cortex(DLPFC)can reduce negative symptoms and improve certain cognitive deficits in schizophrenia patients.However,results are inconsistent across studies.AIM To examine if high-frequency rTMS of the DLPFC can improve visual memory deficits in patients with schizophrenia.METHODS Forty-seven chronic schizophrenia patients with severe negative symptoms on stable treatment regimens were randomly assigned to receive active rTMS to the DLPFC(n=25)or sham stimulation(n=22)on weekdays for four consecutive weeks.Patients performed the pattern recognition memory(PRM)task from the Cambridge Neuropsychological Test Automated Battery at baseline,at the end of rTMS treatment(week 4),and 4 wk after rTMS treatment(week 8).Clinical symptoms were also measured at these same time points using the Scale for the Assessment of Negative Symptoms(SANS)and the Positive and Negative Syndrome Scale(PANSS).RESULTS There were no significant differences in PRM performance metrics,SANS total score,SANS subscores,PANSS total score,and PANSS subscores between active and sham rTMS groups at the end of the 4-wk treatment period,but PRM performance metrics(percent correct and number correct)and changes in these metrics from baseline were significantly greater in the active rTMS group at week 8 compared to the sham group(all P<0.05).Active rTMS treatment also significantly reduced SANS score at week 8 compared to sham treatment.Moreover,the improvement in visual memory was correlated with the reduction in negative symptoms at week 8.In contrast,there were no between-group differences in PANSS total score and subscale scores at either week 4 or week 8(all P>0.05).CONCLUSION High-frequency transcranial magnetic stimulation improves visual memory and reduces negative symptoms in schizophrenia,but these effects are delayed,potentially due to the requirement for extensive neuroplastic changes within DLPFC networks.

Tailoring Classical Conditioning Behavior in TiO_(2) Nanowires:ZnO QDs-Based Optoelectronic Memristors for Neuromorphic Hardware

Neuromorphic hardware equipped with associative learn-ing capabilities presents fascinating applications in the next generation of artificial intelligence.However,research into synaptic devices exhibiting complex associative learning behaviors is still nascent.Here,an optoelec-tronic memristor based on Ag/TiO_(2) Nanowires:ZnO Quantum dots/FTO was proposed and constructed to emulate the biological associative learning behaviors.Effective implementation of synaptic behaviors,including long and short-term plasticity,and learning-forgetting-relearning behaviors,were achieved in the device through the application of light and electrical stimuli.Leveraging the optoelectronic co-modulated characteristics,a simulation of neuromorphic computing was conducted,resulting in a handwriting digit recognition accuracy of 88.9%.Furthermore,a 3×7 memristor array was constructed,confirming its application in artificial visual memory.Most importantly,complex biological associative learning behaviors were emulated by mapping the light and electrical stimuli into conditioned and unconditioned stimuli,respectively.After training through associative pairs,reflexes could be triggered solely using light stimuli.Comprehen-sively,under specific optoelectronic signal applications,the four features of classical conditioning,namely acquisition,extinction,recovery,and generalization,were elegantly emulated.This work provides an optoelectronic memristor with associative behavior capabilities,offering a pathway for advancing brain-machine interfaces,autonomous robots,and machine self-learning in the future.

N:ZnO/MoS_(2)-heterostructured flexible synaptic devices enabling optoelectronic co-modulation for robust artificial visual systems

With the merits of non-contact,highly efficient,and parallel computing,optoelectronic synaptic devices combining sensing and memory in a single unit are promising for constructing neuromorphic computing and artificial visual chip.Based on this,a N:ZnO/MoS_(2)-heterostructured flexible optoelectronic synaptic device is developed in this work,and its capability in mimicking the synaptic behaviors is systemically investigated under the electrical and light signals.Versatile synaptic functions,including synaptic plasticity,long-term/short-term memory,and learning-forgetting-relearning property,have been achieved in this synaptic device.Further,an artificial visual memory system integrating sense and memory is emulated with the device array,and the visual memory behavior can be regulated by varying the light parameters.Moreover,the optoelectronic co-modulation behavior is verified by applying mixed electric and light signals to the array.In detail,a transient recovery property is discovered when the electric signals are applied in synergy during the decay of the light response,of which property facilitates the development of robust artificial visual systems.Furthermore,by superimposing electrical signals during the light response process,a differentiated response of the array is achieved,which can be used as a proof of concept for the color perception of the artificial visual system.

Proteomic and transcriptomic analysis of visual long-term memory in Drosophila melanogaster

The fruit fly,Drosophila melanogaster,is able to discriminate visual landmarks and form visual long-term memory in a flight simulator.Studies focused on the molecular mechanism of long-term memory have shown that memory formation requires mRNA transcription and protein synthesis.However,little is known about the molecular mechanisms underlying the visual learning paradigm.The present study demonstrated that both spaced training procedure(STP)and consecutive training procedure(CTP)would induce long-term memory at 12 hour after training,and STP caused significantly higher 12-h memory scores compared with CTP.Labelfree quantification of liquid chromatography-tandem mass spectrometry(LC-MS/MS)and microarray were utilized to analyze proteomic and transcriptomic differences between the STP and CTP groups.Proteomic analysis revealed 30 up-regulated and 27 down-regulated proteins;Transcriptomic analysis revealed 145 up-regulated and 129 down-regulated genes.Among them,five candidate genes were verified by quantitative PCR,which revealed results similar to microarray.These results provide insight into the molecular components influencing visual long-term memory and facilitate further studies on the roles of identified genes in memory formation.

基于零维碳量子点/二维MoS2混合维异质结晶体管的视觉失忆脉冲光电治疗模拟

失忆症是一种临床常见的疾病,表现为近期记忆的丧失以及获得新记忆能力的全面受损,它严重影响了人类的正常生活.目前,虽然草药干预、蛋白质合成抑制和激素替代可以预防或逆转失忆行为,但这些疗法都相对昂贵且效率低下.本文利用一种先进的光电协同脉冲疗法,基于零维碳量子点/二维MoS_(2)混合维异质结晶体管对视觉失忆行为治疗进行了模拟.其中,光电脉冲可以诱导足够多的电子来填充陷阱态并聚集于零维/二维混合维界面.同时,该异质结晶体管成功实现了生物中可重构的记忆/失忆行为和可调节的视觉记忆巩固功能.更为重要的是,通过实验还证明了光电协同脉冲修复可能对视觉失忆进行有效治疗.这项工作为医学记忆诊断系统、人机实时交互等领域的发展提供了一个新契机.

Air-stable synaptic devices based on bismuth triiodide and carbon nanotubes

Artificial synaptic devices with the functions of emulating important biological synaptic behaviors are playing an increasingly important role in the development of neuromorphic computing systems.Single-walled carbon nanotubes(SWCNTs)with excellent electrical properties and high stability have been studied as active materials for synaptic devices.However,the performance of optical synaptic devices(OSDs)based on pure SWCNTs is limited by the weak light absorption property.Herein,bismuth triiodide(BiI_(3)),an environmentally stable and friendly optoelectronic material,is firstly combined with SWCNTs to fabricate OSDs with decent properties of perceiving and memorizing optical information.The OSDs can exhibit typical synaptic behaviors including excitatory postsynaptic current,paired-pulse facilitation,and short/long-term memory.Distinctively,the photoresponse of the OSD is independent of pulse light wavelength in the range of 365 to 650 nm,different from most of the previously reported OSDs,which usually have wavelength-dependent photo-response.Temperature-dependent photo-response behaviors of the devices are investigated.Importantly,the OSD without encapsulation holds good excitatory post-synaptic current(EPSC)behavior after being stored in the ambient environment for 170 days,indicating reliable environmental stability.Furthermore,an OSD array with nine synaptic devices is employed to mimic the human visual perception and memory functions.These results suggest the feasibility of BiI3/SWCNTs-based OSDs for the simulation of human visual memory.