A Virtual Reality Platform for Context-Dependent Cognitive Research in Rodents.

Animal survival necessitates adaptive behaviors in volatile environmental contexts. Virtual reality (VR) technology is instrumental to study the neural mechanisms underlying behaviors modulated by environmental context by simulating the real world with maximized control of contextual elements. Yet current VR tools for rodents have limited flexibility and performance (e.g., frame rate) for context-dependent cognitive research. Here, we describe a high-performance VR platform with which to study contextual behaviors immersed in editable virtual contexts. This platform was assembled from modular hardware and custom-written software with flexibility and upgradability. Using this platform, we trained mice to perform context-dependent cognitive tasks with rules ranging from discrimination to delayed-sample-to-match while recording from thousands of hippocampal place cells. By precise manipulations of context elements, we found that the context recognition was intact with partial context elements, but impaired by exchanges of context elements. Collectively, our work establishes a configurable VR platform with which to investigate context-dependent cognition with large-scale neural recording.

An intein-split transactivator for intersectional neural imaging and optogenetic manipulation.

The cell-type-specific recording and manipulation is instrumental to disentangle causal neural mechanisms in physiology and behavior and increasingly requires intersectional control; however, current approaches are largely limited by the number of intersectional features, incompatibility of common effectors and insufficient gene expression. Here, we utilized the protein-splicing technique mediated by intervening sequences (intein) and devised an intein-based intersectional synthesis of transactivator (IBIST) to selectively control gene expression of common effectors in multiple-feature defined cell types in mice. We validated the specificity and sufficiency of IBIST to control fluorophores, optogenetic opsins and Ca2+ indicators in various intersectional conditions. The IBIST-based Ca2+ imaging showed that the IBIST can intersect five features and that hippocampal neurons tune differently to distinct emotional stimuli depending on the pattern of projection targets. Collectively, the IBIST multiplexes the capability to intersect cell-type features and controls common effectors to effectively regulate gene expression, monitor and manipulate neural activities.

[Fentanyl attenuates air-puff stimulus-evoked field potential response in the cerebellar molecular layer via inhibiting interneuron activity in mice].

Fentanyl as a synthetic opioid works by binding to the mu-opioid receptor (MOR) in brain areas to generate analgesia, sedation and reward related behaviors. As we know, cerebellum is not only involved in sensory perception, motor coordination, motor learning and precise control of autonomous movement, but also important for the mood regulation, cognition, learning and memory. Previous studies have shown that functional MORs are widely distributed in the cerebellum, and the role of MOR activation in cerebellum has not been reported. The aim of the present study was to investigate the effects of fentanyl on air-puff stimulus-evoked field potential response in the cerebellar molecular layer using in vivo electrophysiology in mice. The results showed that perfusion of 5 µmol/L fentanyl on the cerebellar surface significantly inhibited the amplitude, half width and area under the curve (AUC) of sensory stimulation-evoked inhibitory response P1 in the molecular layer. The half-inhibitory concentration (IC50) of the fentanyl-induced suppression of P1 amplitude was 4.21 µmol/L. The selective MOR antagonist CTOP abolished fentanyl-induced inhibitory responses in the molecular layer. However, application of CTOP alone increased the amplitude and AUC of P1. Notably, fentanyl significantly inhibited the tactile stimulation-evoked response of molecular layer interneurons (MLIs) and the spontaneous firing of MLIs. The results suggest that fentanyl attenuates air-puff stimulus-evoked field potential response in the cerebellar molecular layer via binding to MOR to restrain the spontaneous and evoked firing of MLIs.

[Impacts of shading on seedling growth and mineral accumulation in Paeonia lactiflora]. / é®è«å¤„ç†å¯¹èŠè¯å¹¼è‹—ç”Ÿé•¿å’ŒçŸ¿è´¨è¥å »ç§¯ç´¯çš„å½±å“.

Shading is one of the important strategies to protect seedlings of Paeonia lactiflora. The effects of shading treatments on seedling growth and mineral accumulation of Duolun P. lactiflora were investigated in a greenhouse experiment to provide guidance for P. lactiflora cultivation. One week after emergence, seedlings were treated with 20%, 40%, 60% or 80% shading for two months, with no-shading as the control (CK). The results showed that shading treatments significantly increased plant height by 19.9%, 31.1%, 52.9%, and 63.7%, respectively. However, shading significantly reduced the root mass ratio and root to shoot ratio by 21.5%, 23.6%, 29.2%, 41.8% and 40.6%, 44.0%, 50.9%, 63.2%, respectively. Moreover, 40%, 60% and 80% shading significantly increased specific leaf area by 77.0%, 84.1% and 65.2%, and significantly increased chlorophyll content by 92.3%, 128.7%, 98.1%, and increased carotenoid content by 86.9%, 113.1% and 90.5%, respectively. The treatments of 40%, 60%, and 80% shading significantly decreased root biomass by 61.4%, 74.3% and 78.6%, respectively. Compared with CK, 20%, 40% and 80% shading, the 60% shading treatment increased root phosphorus content by 245.7%, 65.9%, 40.5% and 10.3%, increased potassium content by 102.9%, 131.7%, 57.0%, 63.3% and magnesium content by 131.3%, 55.1%, 40.4%, 7.7%, respectively. 60% shading was an appropriate shading intensity for P. lactiflora seedling cultivation based on local conditions in Duolun.

Fentanyl Inhibits Air Puff-Evoked Sensory Information Processing in Mouse Cerebellar Neurons Recorded in vivo.

Aim: To examine the effects of fentanyl, a potent mu-opioid receptor (MOR) agonist, on-air puff-evoked responses in Purkinje cells (PCs), and molecular layer interneurons (MLIs) using in vivo patch-clamp recordings in anesthetized mice. Methods: Male mice 6-8 weeks-old were anesthetized and fixed on a custom-made stereotaxic frame. The cerebellar surface was exposed and perfused with oxygenated artificial cerebrospinal fluid (ACSF). Patch-clamp recordings in the cell-attached mode were obtained from PCs and MLIs. Facial stimulation by air-puff of the ipsilateral whisker pad was performed through a pressurized injection system. Fentanyl citrate, CTOP, and H-89 dissolved in ACSF were perfused onto the cerebellar surface. Results: Fentanyl significantly inhibited the amplitude and area under the curve (AUC) of sensory stimulation-evoked inhibitory responses in PCs. Although fentanyl did not influence the frequency of simple spikes (SSs), it decreased the pause of SS. The IC50 of the fentanyl-induced suppression of the P1 response amplitude was 5.53 µM. The selective MOR antagonist CTOP abolished fentanyl-induced inhibitory responses in PCs. However, the application of CTOP alone increased the amplitude, AUC of P1, and the pause of SS. Notably, fentanyl significantly inhibited the tactile-evoked response of MLIs but did not affect their spontaneous firing. The fentanyl-induced decrease of inhibitory responses in PCs was partially prevented by a PKA inhibitor, H-89. Conclusions: These results suggest that fentanyl binds to MORs in MLIs to reduce GABAergic neurotransmission in MLI-PC projections and one potential mechanism is via modulation of the cAMP-PKA pathway.

[Effects of fermented cattle dung on the growth and development of Tenebrio molitor larvae].

In order to make use of and industrialize the animal dung from large cattle farms, this paper explored the feasibility of using Tenebrio molitor to digest and utilize cattle dung. Cattle dung was mixed with the conventional feed (65% wheat bran, 30% corn flour, and 5% bean pulp) of T. molitor in definite proportions, and fermented with effective microorganisms (EM). The fermented products containing 60% and 80% of cattle dung (FD1 and FD2, respectively) were selected to feed T. molitor larvae, and the effects of the fermented products on the growth curve, death rate, pupation rate, and antioxidant system of the larvae were compared. Compared with CK (conventional deed), the FD1 made the developmental duration of the larvae prolonged by 10 days and the larvae's death rate upraised somewhat, but made the single larva's total food intake, average body mass, crude fat content, and ratio of unsaturated to saturated fat acids increased by 49%, 28%, 26%, and 32%, respectively (P < 0.05), and the activity of larvae's antioxidant system improved significantly, showing a remarkable adaptability of the larvae to FD1. Unlike FD1, FD2 displayed definite disadvantages in most test growth indicators, as compared with CK, indicating that T. molitor larvae had weak adaptability to FD2. Our findings suggested that using FD1 to feed the 3rd instar of T. molitor larvae would have good practical prospects in industrializing cattle dung.