Evaluation of the long-term memory for thermosensation regulated by neuronal calcium sensor-1 in Caenorhabditis elegans

Objective To evaluate whether the thermotaxis tracking model is suitable for assessing long-term memory （LTM） in the nematode Caenorhabditis elegans. Methods Animals were trained at 20℃ overnight in presence of food. The percentage of animals performing isothermal tracking （IT） behavior was measured at different time intervals after the training. Results The percentage of animals performing IT behavior, the numbers of body bends inside and outside the training temperature, and the expression patterns of AFD and AIY neurons were similar to those in control animals at 36 and 48 h after training; whereas when extending to 60, 72, and 84 h, locomotory behavior defects were observed in the assayed animals, suggesting that this thermal tracking model is feasible for analyzing LTM at 36 and 48 h after training. Moreover, the percent-age of animals performing IT behavior was reduced at 18, 36, and 48 h after training in neuronal calcium sensor-1 gene （nsc-1） mutant animals compared with that in wild-type N2 animals. In addition, exposure to plumbum （Pb） significantly repressed the LTM at 18, 36, and 48 h after training in both wild-type N2 and ncs-1 mutant animals. Conclusion The thermotaxis tracking model is suitable for evaluating the LTM regulated by NCS-1, and can be employed for elucidating regulatory functions of specific genes or effects of stimuli on memory in C. elegans.

Bionic Thermosensation Inspired Temperature Gradient Sensor Based on Covalent Organic Framework Nanofluidic Membrane with Ultrahigh Sensitivity

The ability to precisely monitor temperature at a high resolution is an important task,particularly in terms of safety.Inspired by natural thermosensitive transient receptor potential cation channels,we developed a temperature sensor based on thermaldriven ionic charge separation.To mimic the function of nature,an ionic covalent organic frameworkbased nanofluidic membrane was fabricated.By engineering the membrane to separate two electrolyte solutions,the temperature difference across the membrane can synchronously induce a potential.The high charge density and narrow channel size render extraordinary permselectivity to the membrane,thus offering a thermosensation selectivity of up to 1.25 mV K^(−1),superior to that of any known natural system.Additionally,the generated potential is linearly related to the introduced temperature gradient,thus allowing for precise detection.With these attributes,an alarm device with high thermosensation sensitivity was constructed,demonstrating great promise for environmental temperature monitoring.

Polymodal Functionality of C. elegans OLL Neurons in Mechanosensation and Thermosensation

Sensory modalities are important for survival but the molecular mechanisms remain challenging due to the polymodal functionality of sensory neurons. Here, we report the C. elegans outer labial lateral(OLL) sensilla sensory neurons respond to touch and cold. Mechanosensation of OLL neurons resulted in cell-autonomous mechanically-evoked Ca~(2+) transients and rapidly-adapting mechanoreceptor currents with a very short latency.Mechanotransduction of OLL neurons might be carried by a novel Na~+ conductance channel, which is insensitive to amiloride. The bona fide mechano-gated Na~+ -selective degenerin/epithelial Na~+ channels, TRP-4, TMC, and Piezo proteins are not involved in this mechanosensation.Interestingly, OLL neurons also mediated cold but not warm responses in a cell-autonomous manner. We further showed that the cold response of OLL neurons is not mediated by the cold receptor TRPA-1 or the temperaturesensitive glutamate receptor GLR-3. Thus, we propose the polymodal functionality of OLL neurons in mechanosensation and cold sensation.

Molecular characteristics and temperature tolerance function of the transient receptor potential in the native Bemisia tabaci AsiaII3 cryptic species

Insects are poikilothermic animals,and temperature is one of the most important abiotic factors affecting their spread and distribution.For example,differences in thermal tolerance may underlie the significant differences in geographical distributions between the native AsiaII3 and invasive MED(Mediterranean)cryptic Bemisia tabaci species in China.Transient receptor potential(TRP)channels are key components of the insect temperature perception system and act as molecular thermometers since they can be activated by specific changes in temperature.In this study,we cloned and characterized the AsiaII3 BtTRP gene and revealed its functions in the response to thermal stress.The full-length cDNA of BtTRP was 3821 bp,with a 3501-bp open reading frame encoding a 132.05-kDa protein.Comparing the deduced amino acid sequences of AsiaII3 BtTRP and MED TRP revealed five amino acid differences.In situ hybridization indicated that BtTRP might be widely expressed throughout the AsiaII3 adult body.BtTRP mRNA expression reached the highest levels after exposure to mild thermal stimuli(12 and 35°C),showing that BtTRP expression can be induced by temperature stress.Furthermore,the thermal tolerance of AsiaII3 after BtTRP dsRNA feeding was significantly lower than that of the control.Taken together,the present study highlights the importance of TRP channels for B.tabaci thermal resistance,and allows us to infer that the differences in amino acids between AsiaII3 and MED might cause the differences in thermal tolerance of these two cryptic species.This study provides a new direction for investigating geographic distribution differences between invasive and native insects.

The molecular basis of heat stress responses in plants

Global warming impacts crop production and threatens food security.Elevated temperatures are sensed by different cell components.Temperature increases are classified as either mild warm temperatures or excessively hot temperatures,which are perceived by distinct signaling pathways in plants.Warm temperatures induce thermomorphogenesis,while high-temperature stress triggers heat acclimation and has destructive effects on plant growth and development.In this review,we systematically summarize the heat-responsive genetic networks in Arabidopsis and crop plants based on recent studies.In addition,we highlight the strategies used to improve grain yield under heat stress from a source-sink perspective.We also discuss the remaining issues regarding the characteristics of thermosensors and the urgency required to explore the basis of acclimation under multifactorial stress combination.

Study on the thermesthesia features of heatsensitive acupoints in patients with knee osteoarthritis

Objective： To observe the thermesthesia thresholds of the heat-sensitive acupoints in patients with knee osteoarthritis （KOA）, and to provide scientific evidence for acupoint selection based on acupoint sensitization. Methods： Forty-six patients with KOA of swelling type were recruited. By using the quantitative thermesthesia testing, the thermal sensation threshold, thermal pain threshold, and threshold of thermal pain tolerance at Xuehai （SP 10）, Neixiyan （EX-LE 4） and Yinlingquan （SP 9） were detected. The subjects were then divided into heat-sensitive groups and non-heat-sensitive groups according to whether there was a phenomenon of heat-sensitive moxibustion sensation at each acupoint, to compare the thermesthesia thresholds between the two groups. Results： The thermal sensation threshold, thermal pain threshold, and threshold of thermal pain tolerance were respectively （38.21±2.03） ℃, （44.47±1.86） ℃ and （48.59＋0.74） ℃ in the heat-sensitive group of Xuehai （SP 10）, versus （36.76±1.93） ℃, （42.91±2.05） ℃ and （46.95±1.14） ℃ in the non-heat-sensitive group of Xuehai （SP 10）; the thermal sensation threshold, thermal pain threshold, and threshold of thermal pain tolerance were respectively （37.47±1.77）℃, （44.55＋1.63） ℃, and （47.48±0.47） ℃ in the heat-sensitive group of Neixiyan （EX-LE 4）, versus （35.92±1.69） ℃, （42.72±1.94）℃ and （45.53±0.41） ℃ in the non-heat-sensitive group of Neixiyan （EX-LE 4）; the thermal sensation threshold, thermal pain threshold, and threshold of thermal pain tolerance were respectively （37.30±2.23） ℃, （44.39±1.92） ℃ and （47.76±0.58） ℃ in the heat-sensitive group of Yinlingquan （SP 9）, versus （36.06±1.86） ℃, （42.63±1.88） ℃ and （45.91±0.72） ℃ in the non-heat-sensitive group of Yinlingquan （SP 9）. The statistical analyses showed that the thermal sensation threshold, thermal pain threshold, and threshold of thermal pain tolerance of each heat-sensitive group （all the three acupoints） were significantly higher than those of each corresponding non-heat-sensitive group （P〈0.01）. Conclusion： There were differences in the thermesthesia thresholds between heat-sensitized and non-heat-sensitized acupoints in patients with KOA of swelling type; and the thermal sensation threshold, thermal pain threshold, and threshold of thermal pain tolerance of the heat-sensitized points were significantly higher than those of the non-heat-sensitized ones.

Studies on ciliotoxicity of nasal thermosensible gels of Chinese medicine Xingbi

We studied the effects of nasal thermosensible gels containing Chinese medicine Xingbi on Bufo gargarizans maxillary mucosal cilia movement and the ciliotoxicity in rats nasal mucosa. The saline water was used as a blank control, and 1% hydrochloric acid of methamphetamine Massachusetts was used as the negative control. Compared with normal saline control, the relative percentage of the lasting time of ciliary movement treated with Chinese medicine Xingbi was 94.1%. There was no remarkable pathological change in the tissue slice of nasal mucosa, and no stimulation on nasal mucous membrane was observed. So these data suggest that nasal thermosensible gel of Chinese medicine Xingbi is of high safety. It has no damage to the mucosa of toads and rats and can be used for intranasal administration.