Methcathinone Increases Visually-evoked Neuronal Activity and Enhances Sensory Processing Efficiency in Mice / 神经科学通报·英文版

Methcathinone (MCAT) belongs to the designer drugs called synthetic cathinones, which are abused worldwide for recreational purposes. It has strong stimulant effects, including enhanced euphoria, sensation, alertness, and empathy. However, little is known about how MCAT modulates neuronal activity in vivo. Here, we evaluated the effect of MCAT on neuronal activity with a series of functional approaches. C-Fos immunostaining showed that MCAT increased the number of activated neurons by 6-fold, especially in sensory and motor cortices, striatum, and midbrain motor nuclei. In vivo single-unit recording and two-photon Ca2+ imaging revealed that a large proportion of neurons increased spiking activity upon MCAT administration. Notably, MCAT induced a strong de-correlation of population activity and increased trial-to-trial reliability, specifically during a natural movie stimulus. It improved the information-processing efficiency by enhancing the single-neuron coding capacity, suggesting a cortical network mechanism of the enhanced perception produced by psychoactive stimulants.

Responses of Primary Afferent Fibers to Acupuncture-Like Peripheral Stimulation at Different Frequencies: Characterization by Single-Unit Recording in Rats / 神经科学通报·英文版

The pain-relieving effect of acupuncture is known to involve primary afferent nerves (PANs) via their roles in signal transmission to the CNS. Using single-unit recording in rats, we characterized the generation and transmission of electrical signals in Aβ and Aδ fibers induced by acupuncture-like stimuli. Acupuncture-like signals were elicited in PANs using three techniques: manual acupuncture (MAc), emulated acupuncture (EAc), and electro-acupuncture (EA)-like peripheral electrical stimulation (PES). The discharges evoked by MAc and EAc were mostly in a burst pattern with average intra-burst and inter-burst firing rates of 90 Hz and 2 Hz, respectively. The frequency of discharges in PANs was correlated with the frequency of PES. The highest discharge frequency was 246 Hz in Aβ fibers and 180 Hz in Aδ fibers. Therefore, EA in a dense-disperse mode (at alternating frequency between 2 Hz and 15 Hz or between 2 Hz and 100 Hz) best mimics MAc. Frequencies of EA output >250 Hz appear to be obsolete for pain relief.

Study of blood component therapy in obstetrics

Background: Blood transfusion is a life saving measure. Various pregnancy complications and disorders of labor present as risk factors for extra blood loss during pregnancy and cause severe hemodynamic instability. This along with complications due to abortion (spontaneous or induced) and ruptured ectopic pregnancy show up as conditions needing transfusion in the day-to-day practice of obstetrics. In a country like India, limited and fixed resources of blood, forces us to titrate the use of blood and its components. Normally, blood loss during birth is well-tolerated because of changes during pregnancy.Methods: This is a retrospective observational study done at tertiary care hospital. This study is based on study of indoor patients admitted during one year duration. Detailed history and all necessary investigations were carried out. Details regarding blood transfusion were taken indication of blood transfusion, number and type of unit transfused, number of patients given blood components, indications where single unit was transfused. Analysis of the data was done.Results: Anemia followed by antepartum hemorrhage followed by postpartum hemorrhage was the major cause for blood and blood product transfusion. Approximately 60% patients required two units of PCV (Packed Cell Volume) transfusion. Anemia in pregnancy was the major cause of single unit PCV transfusion.Conclusions: A proper knowledge for blood and blood product transfusion is needed to make it available for people who are actually in need and also to decrease the economic burden. Measures to prevent anemia should be implemented. Active management of third stage of labour (AMTSL) should be done to avoid postpartum hemorrhage. Single unit transfusion should be avoided.

Effect of infralimbic area H2S system on fear extinction of rats and its mechanism / 中国药理学通报

Dept of Physiology, School of Basic Medical Sciences, Bitehou Medical University, Yantai Shandong 264003, China Aim To explore the behavior and CBS/H2S levels in infralimbic (IL) medial prefrontal cortex (mPFC) in conditioned fear rats and study the effect of exogenous H2S on conditioned fear extinction of rats and the related mechanism. Methods The rat conditioned fear model was established with sound pairing with an aversive foot shock. Later the repeated single sound was used for extinction training. CBS/H2S con-tent in IL tissues was measured using Western blot and methylene blue method. In vivo extracellular single u-nit recordings were used to examine the frequency of spontaneous discharges of IL neurons. Results 1. CBS/H2S level in IL tissues of conditioned fear model (control group) decreased (P <0. 01) and the freezing level was aggravated (P < 0. 01) , while after extinction training CBS/H2 S level increased (P < 0.01, P < 0. 05) and the freezing level was alleviated (P < 0.01). 2. Freezing level decreased in NaHS group compared with extinction group (P <0. 01) . 3. L-cys-teine increased the frequency of spontaneous discharges of IL neurons (P < 0. 01). Conclusions Learning and memory ability decreases in PTSD model rats owing to the inhibition of CBS/H2S content in IL tissues. The mechanism of behavior improvement of H2S on PTSD model rats may be related to the excitation of H2S on frequency of spontaneous discharges of IL neurons.

The design and experience of experiment teaching in neuronal discharge evoked by the optogenetics / 中华医学教育探索杂志

The recording and analysis for the neurons' single unit discharge is one of the important content among the comprehensive experiments in basic medicine.However,the traditional experiment cannot help the students to understand the mechanism of the action potential.According to the high comprehensive quality and high requirements of training in eight-year medical students,in the past two years,we have entrained the optogenetics into the single unit recording experiment and set up an experiment of neuronal discharge evoked by the optogenetics.In this article,we the introduce teaching design of the recording and analysis of the unit discharges induced by light genetics,sum up teaching experience and put forward our own thinking.

Effect of H2 S system on space learning and memory ability in PTSD model rat and on the frequency of spontaneous discharges of hippocampus neurons / 中国药理学通报

Aim To explore the behavior and CBS /H2 S levels of hippocampus in post traumatic stress dis-order (PTSD)rats and study the effect of exogenous H2 S on PTSD rats.Methods Single prolonged stress paradigm was adopted to prepare PTSD animal model. Morris water maze test was adopted to test space learn-ing and memory ability.CBS /H2 S content in hippo-campus tissue sample was measured using Western blot and methylene blue method.In vivo extracellular single unit recording was used to examine the frequency of spontaneous discharges of hippocampus neurons.Re-sults ① Escape latency increased and quadrant time (%)and platform crossing times decreased in Morris water maze test of PTSD group compared with normal group(P <0.01 ).CBS /H2 S level in hippocampus tis-sue of PTSD group also decreased compared with nor-mal group (P <0.01 ,P <0.05 ).② Escape latency decreased and quadrant time(%)and platform cross-ing times increased in Morris water maze test of NaHS+PTSD group compared with PTSD group(P <0.01 ).③ L-cysteine increased the frequency of spontaneous discharges of hippocampus neurons(P < 0.01 ).Con-clusions Learning and memory ability decrease in PTSD model rats owing to the inhibition of CBS /H2 S content in hippocampus tissue.The mechanism of be-havior improvement of H2 S on PTSD model rat is possi-bly related to the excitation of H2 S on frequency of spontaneous discharges of hippocampus neurons.

Development of single unit floating-pulsatile site specific drug delivery system for chronotherapeutic release of aceclofenac.

Chronopharmaceutics is a branch of pharmaceutics devoted to the design and evaluation of drug delivery systems that release a bioactive agent at a rhythm that ideally matches the biological requirement of a given disease therapy. A major objective of chronotherapy in the treatment of several diseases is to deliver the drug in higher concentrations during the time of greatest need according to the circadian onset of diseases or symptoms.. The main objective of the present study was to develop single-unit floating-pulsatile drug delivery system for obtaining no drug release during floating and in the proximal small intestine followed by pulsed drug release in distal small intestine to achieve chronotherapeutic release of aceclofenac for treatment of rheumatoid arthritis, osteoarthritis, spondylytis and to improve the patient compliance.

Short implants with single-unit restorations in posterior regions with reduced height: a retrospective study

Aim: Previous studies have shown excellent prognosis with short implants. However, evidence of short implants rehabilitated with single-unit restorations is scarce. The purpose of this study was to evaluate the percentage of success of short implants in posterior maxillary and mandibular regions with single-unit restorations. Methods: This study comprised a retrospective analysis of data of 41 patients that received 54 short implants between 2004 and 2009. All implants were placed by the same surgeon and all restorations were performed by experienced professionals. All implants were placed in sites with reduced bone volume; 48 implants were evaluated by computed tomography and 6 implants by radiography. Failures and biological complications were analyzed. Results: It was observed a success rate of 96.3% in the osseointegration period and 100% in the load period that ranging from 7 to 38 months. Two complications were observed, which were successfully treated without risk of implant loss. Conclusions: Short implants in posterior regions rehabilitated with single-unit restorations are a treatment option with high success rate and thus may be indicated in posterior regions with reduced bone height.

Evaluating the Appropriateness of a Single Unit Transfusion / 대한수혈학회지

BACKGROUND: The domestic quantity of blood components consumed has been decreasing since 2002, but the rate of a single unit RBC transfusion (SUT) has been on the increase. In the past, a SUT was regarded as an uncesssary procedure, but currently is considered as an effective method to maintain a minimal hemoglobin concentration for physiological needs. We investigated the actual conditions of a SUT. METHODS: We analyzed 800 cases of SUTs performed at a tertiary care university hospital between March 2006 March and February 2007. The subjects of the study were divided into a surgical group (n=561) and medical group (n=239) for the purpose of RBC unit usage and were analyzed by groups and ordering departments, with an analysis of the pre and post-transfusion hemoglobin concentration and hematocrit values. The distribution according to the pre and post-transfusion hemoglobin ranges were calculated. RESULTS: The mean hemoglobin concentration increment of the surgical group was significantly lower than that of the medical group (P<0.0001) and the mean pre and post-transfusion hemoglobin concentrations of the medical group were lower than that of the surgical group (P<0.0001). Approximately 26% cases of the SUTs performed in the surgical group were appropriate, based on a post-transfusion hemoglobin concentration below 10 g/dL. In the medical group, about 75% of the SUTs were appropriate based on a pre-transfusion hemoglobin concentration below 9 g/dL. CONCLUSION: Most transfusions are decided based on various clinical situations and opinions of the clinicians. Therefore, continuous evaluation of the appropriateness of transfusion is necessary. In our study, the appropriateness of a SUT was estimated indirectly based on the pre and post-transfusion hemoglobin concentration. Consequently, policies and strategies for performing asingle unit RBC transfusion are required.

Activity of Single Granule Cell in the Dentate Gyrus of Guinea Pig During The Consolidation of Trace Eyeblink Conditioned Responses / 生物化学与生物物理进展

The hippocampus plays a critical role during the consolidation of trace eyeblink conditioned responses (CRs). However, the role of its related structure such as dentate gyms (DG) remains unclear. The present study was aimed at monitoring the activity of single granule cell in the DG during the consolidation of trace eyeblink CRs, and elucidating the possible role of DG during this hippocampus-dependent task. Guinea pigs (n=8) were trained on a trace eyeblink conditioning paradigm using a 200-ms tone conditioned stimulus (CS), a 200-ms corneal airpuff unconditioned stimulus (US) and a 600-ms trace interval. Controls consisted of pseudo- conditioned guinea pigs (n=8). Extracellular single unit recordings in vivo were performed in the DG of learner animals during the consolidation of trace eyeblink CRs. The results revealed that all the trace-conditioned animals acquired the trace eyeblink CRs over 14 training days, however, none of the pseudo-conditioned animals did. Furthermore, 23 of 40 single granule cells in the DG of learner animals exhibited heterogeneous activity patterns during the consolidation of trace eyeblink CRs such as increases in activities to the tone CS, trace interval or airpuff US. The results suggested that the DG might participate in the neural circuit important for the consolidation of trace eyeblink CRs, and that the granule cells might encode different information during the consolidation of trace eyeblink CRs.

Differential Changes in Neural Activity of Prefrontal Cortical Neurons of Behaving Rats by Clozapine Administration / 대한정신약물학회지

OBJECTIVE: A previous study indicated that acute treatment of clozapine increased the neural activity of prefrontal cortical neurons of anesthetized rats. This study was to investigate the effect of clozapine on prefrontal cortical neurons in behaving rats. METHODS: Neural activities of prefrontal cortical neurons of behaving rats were measured before and after clozapine administration using single unit recording. RESULTS: Sixty nine single units (N=69) in the medial prefrontal cortex were isolated in forty three Sprague-Dawley rats. Although clozapine did not change the overall average firing rate of prefrontal cortical neurons, there was a tendency to increase in the neural activity of neurons with low firing rate that were considered to be putative pyramidal cells (N=40). In contrast, neurons with high firing rate assumed to be putative interneurons (N=29) tended to decrease in neural activity by clozapine treatment. CONCLUSION: This result suggests that clozapine treatment enhances the neural activity of pyramidal cells and to inhibit interneurons in the prefrontal cortex. It is speculated that the enhancement of neural activity of pyramidal cells in the prefrontal cortex by clozapine treatment may contribute to its therapeutic effect.

Observation of the Spontaneous Discharge of Auditory Nerve Primary Fibers / 听力学及言语疾病杂志

Being fundamental preparation for the research of cochlear implants, study of tinnitus's mechanism and establishment of the animal model, the spontaneous discharge of single unit of auditory nerve primary fibers in normal cat was observed and analyzed. They include: Ⅰ, How to identify the spontaneous discharge potential in auditory nerve primary firbers. Ⅱ, The waveform of the spontaneous discharge potential in auditory never, Ⅲ, The discharge rate of spontaneous discharge in auditory nerve primary fibers. Ⅳ, The temporal feature of the spontaneous discharge. Ⅴ, The origin of the spontaneous discharge.