Two-Photon FRET/FLIM Imaging of Cerebral Neurons.

Two-photon FRET (Förster resonance energy transfer) and FLIM (fluorescence lifetime imaging microscopy) enable the detection of FRET changes of fluorescence reporters in deep brain tissues, which provide a valuable approach for monitoring target molecular dynamics and functions. Here, we describe two-photon FRET and FLIM imaging techniques that allow us to visualize endogenous and optogenetically induced cAMP dynamics in living neurons with genetically engineered FRET-based cAMP reporters.

Jigsaw Classroom: Perceptions of Students and Teachers.

Background: Various innovative teaching methods have been designed in an attempt to provide millennial students an interactive and stimulating learning environment. A jigsaw method is one such form of cooperative learning that enables students to develop critical-thinking and ability for effective communication and promotes positive student attitudes toward their own learning. The present study was thus undertaken to introduce a jigsaw-based cooperative learning method and to understand the perception of the students and faculty. Methodology: This was a cross-sectional study conducted among second year MBBS students. Students were randomly divided into 10 parent groups, with 10 students each. The topic was divided into 10 subtopics. Each student in the parent group was allotted a sub-topic. The students who were given the same sub-topic assembled to form an expert group. They interacted and discussed the subtopic. Students finally returned to their parent groups for peer teaching and presentation. A validated questionnaire was used to gather students and faculty feedback. Descriptive statistics were used to analyze responses to the Likert scale questions. Qualitative data was analyzed using thematic analysis. Results: The present study included 95 s year MBBS students. Majority (81%) students agreed that this teaching learning method enhanced their communication skills. Seventy-five percent of the students agreed that the activity helped in overcoming shyness and hesitation in the class. Overall the faculty also agreed that the jigsaw method was helpful for the students. Conclusions: Cooperative learning like jigsaw facilitates learning allowing student-student discussion, improving communication and teaching skills.

Neuronal SNAP-23 is critical for synaptic plasticity and spatial memory independently of NMDA receptor regulation.

SNARE-mediated membrane fusion plays a crucial role in presynaptic vesicle exocytosis and also in postsynaptic receptor delivery. The latter is considered particularly important for synaptic plasticity and learning and memory, yet the identity of the key SNARE proteins remains elusive. Here, we investigate the role of neuronal synaptosomal-associated protein-23 (SNAP-23) by analyzing pyramidal-neuron specific SNAP-23 conditional knockout (cKO) mice. Electrophysiological analysis of SNAP-23 deficient neurons using acute hippocampal slices showed normal basal neurotransmission in CA3-CA1 synapses with unchanged AMPA and NMDA currents. Nevertheless, we found theta-burst stimulation-induced long-term potentiation (LTP) was vastly diminished in SNAP-23 cKO slices. Moreover, unlike syntaxin-4 cKO mice where both basal neurotransmission and LTP decrease manifested changes in a broad set of behavioral tasks, deficits of SNAP-23 cKO are more limited to spatial memory. Our data reveal that neuronal SNAP-23 is selectively crucial for synaptic plasticity and spatial memory without affecting basal glutamate receptor function.

Hydroxychloroquine: Adverse Drug Reaction Profile of an Old Drug in a New Situation.

BACKGROUND: Hydroxychloroquine (HCQ) has been extensively used during the COVID-19 pandemic both as a therapeutic and prophylactic drug. HCQ is generally well tolerated; however, adverse drug reactions (ADRs) in COVID-19 need further exploration. In this study, we have determined the type and pattern of ADRs of HCQ as a prophylactic and therapeutic drug in COVID-19. METHODS: All spontaneous suspected ADR reports due to HCQ in COVID-19 patients submitted to the ADR monitoring of a tertiary care hospital were included. Additionally, a survey was designed for active surveillance of ADRs among healthcare professionals (HCPs) who were on prophylaxis with HCQ. The ADRs were analyzed to determine severity, causality, and preventability using the Hartwig Scale, World Health Organisation-Uppasala Monitoring Centre (WHO-UMC) scale, and modified Schumock and Thornton criterion respectively. RESULTS: Sixty-four ADR reports were received from COVID-19 patients. A total of 78 ADRs were reported by 49 HCPs who were on HCQ prophylaxis. The majority of the patients had ADRs related to skin and soft tissues (37.5%), whereas the HCPs on prophylaxis mostly had gastrointestinal complaints (42.3%). ADRs observed in HCPs on prophylaxis were mild, not requiring any intervention. However, 50% of ADRs in patients were of "moderate" category. CONCLUSION: Undiscerning and unsupervised use of HCQ can expose the general population as well as patients to serious adverse drug effects. Utmost care is necessary before using HCQ prophylactically or for treatment in COVID-19.

Correction to: Vaccine Hesitancy as a Challenge or Vaccine Confidence as an Opportunity for Childhood Immunisation in India.

In the original publication, the fourth author name was incorrectly published as Jayant Ray.

Optogenetic Manipulation of Postsynaptic cAMP Using a Novel Transgenic Mouse Line Enables Synaptic Plasticity and Enhances Depolarization Following Tetanic Stimulation in the Hippocampal Dentate Gyrus.

cAMP is a positive regulator tightly involved in certain types of synaptic plasticity and related memory functions. However, its spatiotemporal roles at the synaptic and neural circuit levels remain elusive. Using a combination of a cAMP optogenetics approach and voltage-sensitive dye (VSD) imaging with electrophysiological recording, we define a novel capacity of postsynaptic cAMP in enabling dentate gyrus long-term potentiation (LTP) and depolarization in acutely prepared murine hippocampal slices. To manipulate cAMP levels at medial perforant path to granule neuron (MPP-DG) synapses by light, we generated transgenic (Tg) mice expressing photoactivatable adenylyl cyclase (PAC) in DG granule neurons. Using these Tg(CMV-Camk2a-RFP/bPAC)3Koka mice, we recorded field excitatory postsynaptic potentials (fEPSPs) from MPP-DG synapses and found that photoactivation of PAC during tetanic stimulation enabled synaptic potentiation that persisted for at least 30 min. This form of LTP was induced without the need for GABA receptor blockade that is typically required for inducing DG plasticity. The paired-pulse ratio (PPR) remained unchanged, indicating the cAMP-dependent LTP was likely postsynaptic. By employing fast fluorescent voltage-sensitive dye (VSD: di-4-ANEPPS) and fluorescence imaging, we found that photoactivation of the PAC actuator enhanced the intensity and extent of dentate gyrus depolarization triggered following tetanic stimulation. These results demonstrate that the elevation of cAMP in granule neurons is capable of rapidly enhancing synaptic strength and neuronal depolarization. The powerful actions of cAMP are consistent with this second messenger having a critical role in the regulation of synaptic function.

Vaccine Hesitancy as a Challenge or Vaccine Confidence as an Opportunity for Childhood Immunisation in India.

Vaccines have contributed substantially to decreasing the morbidity and mortality rates of many infectious diseases worldwide. Despite this achievement, an increasing number of parents have adopted hesitant behaviours towards vaccines, delaying or even refusing their administration to children. This has implications not only on individuals but also society in the form of outbreaks for e.g. measles, chicken pox, hepatitis A, etc. A review of the literature was conducted to identify the determinants of vaccine hesitancy (VH) as well as vaccine confidence and link them to challenges and opportunities associated with vaccination in India, safety concerns, doubts about the need for vaccines against uncommon diseases and suspicions towards new vaccines were identified as major vaccine-specific factors of VH. Lack of awareness and limited access to vaccination sites were often reported by hesitant parents. Lastly, socio-economic level, educational level and cultural specificities were contextual factors of VH in India. Controversies and rumours around some vaccines (e.g., human papillomavirus) have profoundly impacted the perception of the risks and benefits of vaccination. Challenges posed by traditions and cultural behaviours, geographical specificities, socio-demographic disparities, the healthcare system and vaccine-specific features are highlighted, and opportunities to improve confidence are identified. To overcome VH and promote vaccination, emphasis should be on improving communication, educating the new generation and creating awareness among the society. Tailoring immunisation programmes as per the needs of specific geographical areas or communities is also important to improve vaccine confidence. Fig. 1 Plain language summary.