[Alteration of neural oscillations in hippocampal CA3 area in the fast avoidance response rat before and after electric shock avoidance training].

The purpose of the present study is to explore the relationship of spatial learning ability and specific electrical activities of neural oscillations in the rat. The fast and general avoidance response groups were selected on the basis of the animals' responses to the electric shock in Y type maze, and their local field potentials (LFPs) of hippocampal CA3 area were recorded by wireless telemetry before and after shock avoidance training, respectively. The components of neural oscillations related to spatial identifying and learning ability were analyzed. The results showed that, compared with the general avoidance response group, the fast avoidance response group did not show any differences of LFPs in hippocampal CA3 area before electric shock avoidance trial, but showed significantly increased percentages of 0-10 Hz and 30-40 Hz rhythm in right hippocampal CA3 area after the shock avoidance training (P < 0.01 or P < 0.05). Fast Fourier transform showed that percentage increase of 0-10 Hz band occurred mainly in θ (3-7 Hz) frequency, and 30-40 Hz frequency change was equivalent to the γ1 band. Furthermore, compared with those before training, only the percentages of ß, ß2 (20-30 Hz) and γ1 rhythm increased (P < 0.01 or P < 0.05) in fast avoidance response rats after training, while the θ rhythm percentage remained unchanged. In contrast, θ rhythm percentage and the large amplitude (intensity: +2.5 - -2.5 db) θ waves in right CA3 area of general avoidance response rats were significantly reduced after training (P < 0.01). These results suggest that the increased percentages of ß2 and γ1 rhythm and high-level (unchanged) percentage of θ rhythm in the right hippocampus CA3 area might be related to strong spatial cognition ability of fast avoidance response rats.

[Wavelet packet extraction and entropy analysis of telemetry EEG from the prelimbic cortex of medial prefrontal cortex in morphine-induced CPP rats].

The purpose of the present study is to analyze the relationship between the telemetry electroencephalogram (EEG) changes of the prelimbic (PL) cortex and the drug-seeking behavior of morphine-induced conditioned place preference (CPP) rats by using the wavelet packet extraction and entropy measurement. The recording electrode was stereotactically implanted into the PL cortex of rats. The animals were then divided randomly into operation-only control and morphine-induced CPP groups, respectively. A CPP video system in combination with an EEG wireless telemetry device was used for recording EEG of PL cortex when the rats shuttled between black-white or white-black chambers. The telemetry recorded EEGs were analyzed by wavelet packet extraction, Welch power spectrum estimate, normalized amplitude and Shannon entropy algorithm. The results showed that, compared with operation-only control group, the left PL cortex's EEG of morphine-induced CPP group during black-white chamber shuttling exhibited the following changes: (1) the amplitude of average EEG for each frequency bands extracted by wavelet packet was reduced; (2) the Welch power intensity was increased significantly in 10-50 Hz EEG band (P < 0.01 or P < 0.05); (3) Shannon entropy was increased in ß, γ1, and γ2waves of the EEG (P < 0.01 or P < 0.05); and (4) the average information entropy was reduced (P < 0.01). The results suggest that above mentioned EEG changes in morphine-induced CPP group rat may be related to animals' drug-seeking motivation and behavior launching.

[Telemetry EEG of parietal association cortex in heroin-induced CPP rats].

OBJECTIVE: To determine the relationship between EEG changes of parietal association cortex (PtA) and drug-seeking behaviors of heroin-induced conditioned place preference (CPP) rats. METHODS: Stereotaxic electrode was buried in the PtA of rats, which were then divided randomly into heroin-induced CPP group and operation-only control group. A CPP video system in combination with EEG wireless telemetry was used for recording PtA EEG and the behaviors of the rats-staying in black or white chamber of the video box; shuttling between black-white chambers or between white-black chambers. RESULTS: No significant difference in percentage of the telemetry EEG waves was found between the two groups of rats when they stayed in the black or white chambers. The heroin-induced CPP rats had increased percentage of delta waves (P < 0.05) on the right PtA and decreased percentage of beta and beta2 waves on both right and left PtA (P < 0.05) when they shuttled between two chambers. Compared with the operation-only controls, significant decrease in the percentage of delta waves on both left and right PtA and increase in theta, alpha and alpha1 waves were evident (P < 0.05) only when the heroin-induced CPP rats shuttled between white-black chambers. CONCLUSION: EEG changes on PtA of heroin-induced CPP rats differ between staying and shuttling states. Such changes may not be associated with drug-seeking behaviors.

[Identification of the status of individual drug-administration behavior in heroin-withdrawal rats based on FrA EEG].

Objective: To identify the compulsive drug-seeking behavior of the individual in the heroin-addicted rat, a novel analysis method of telemetering electroencephalogram (EEG) in the frontal association cortex (FrA) induced by heroin-dependent position preference in rats. Methods: Thirty clean-grade Wistar rats after implantation of prefrontal cortex electrodes, were randomly divided into the surgical control group (n=10) and heroin-inducing group (n=20). The heroin-induced group was subcutaneously injected with heroin 0.5 mg/(kg.d), and then increased daily by 0.25 mg/kg for seven days. The control group was injected with the same amount of normal saline at the same time. Using the CPP video system combined with electroencephalogram (EEG) wireless telemetry technology, EEG signals in FrA areas of the addicted rats were recorded simultaneously in four behaviors: white-black shuttle, black-white shuttle, black-chamber stay and white-chamber stay. The areas with EMG and other noisy signals in the original EEG were identified, and wavelet decomposition and amplitude threshold denoising pre-processing were used. The sample entropy values of EEG data and wavelet coefficients corresponding to 4 rhythm frequencies under different behavioral states standard deviation were extracted, and support vector machine algorithm (SVM) was used to achieve real-time identification of different behavioral states of heroin-addicted rats. Results: SVM real-time classification recognition rate of 20 heroin abstinence rats, which are staying in black or white chamber of video box, shuttling between black-white chambers or between white - black chambers, was about 80%. Among them, the real-time recognition rate of black-white shuttle, which is closely related to drug-seeking behavior, reached 83.88%. Conclusion: In this paper, the real-time identification method of heroin-induced obsessive-compulsive drug-seeking behavior in rats can be used as an effective method to detect the initiation and occurrence of heroin-seeking drug-seeking behavior in rats. It can be used for the clinical observation of heroin-dependent patients and the prevention of drug-seeking behavior.

Study of The Y-STR Multiplex Microfluidic Chip Rapid Amplification System / 生物化学与生物物理进展

ObjectiveAt present, the matching reagents of commercially available rapid DNA instruments based on microfluidics chip technology are autosome short tandem repeat (STR) individual identification reagents. The non-recombining part of the human Y chromosome is widely used in forensic DNA analysis, particularly in cases where standard autosomal DNA profile is uninformative. Y-STR loci are useful markers to identify males and male lineages in forensic practice. In order to achieve rapid and fully integrated detection ofY-STR loci, this study constructed the RTyper Y27 microfluidic chip rapid detection system and validated the performance of this system. MethodsThe system was verified and evaluated by sensitivity, success rate, typing accuracy, peak height balance, sizing precision and accuracy, mock case sample tests, mixture detection ability, and inhibition tolerance. ResultsComplete Y-STR profiles can be obtained when the template amount of DNA standard 9948 was ≥8 ng, the number of blood cards was ≥3 pieces, and the number of oral swab scrapings was≥7 times. The success rate of fully integrated detection was 91.52%, and the concordance rates was 99.74% for 165 testing samples. The success rate of 115 blood spots in these samples was 90.43%, with a typing accuracy of 99.65%, the success rate of 50 buccal swabs was 94%, with a typing accuracy of 99.92%. There was no significant difference in typing accuracy between blood spots and buccal swab samples. The peak height ratio between different fluorescence channels was 89.81%. The standard deviation of allelic ladder for 10 runs was within 0.5 bp. The size differences between allele and corresponding allele in allelic ladder was within 0.5 bp. The maximum precision CV values within and between batches were 0.48% and 0.68%, respectively, which were lower than 15%. These data indicate that the system has good accuracy and precision. The system was capable of accurately typing oral swabs, blood cards, saliva cards, cigarette butts, blood swabs and seminal stains. Complete Y-STR profiles can be obtained and distinguish at the 1∶3 ratio of minor and major contributors in artificial male DNA mixtures. Complete Y-STR genotyping can be obtained under the interference of inhibitors, such as different concentrations of humic acid (50-400 mg/L), indigotin (20-100 nmol/L) and hemoglobin (100-500 μmol/L). ConclusionIn this study, the RTyper Y27 microfluidic chip rapid amplification system is combined with the Quick TargSeq 1.0 integrated system, and the Y-STR profile can be obtained in approximately 2 h. Through a series of verification experiments, the results show that the system has good repeatability, accuracy and stability, can meet the on-site Y-STR detection requirements, and can be used in forensic practice.

Sources of calcium in agonist-induced contraction of rat distal colon smooth muscle in vitro.

AIM: To study the origin of calcium necessary for agonist-induced contraction of the distal colon in rats. METHODS: The change in intracellular calcium concentration ([Ca2+]i) evoked by elevating external Ca2+ was detected by fura 2/AM fluorescence. Contractile activity was measured with a force displacement transducer. Tension was continuously monitored and recorded using a Powerlab 4/25T data acquisition system with an ML110 bridge bioelectric physiographic amplifier. RESULTS: Store depletion induced Ca2+ influx had an effect on [Ca2+]i. In nominally Ca2+-free medium, the sarco-endoplasmic reticulum Ca2+-ATPase inhibitor thapsigargin (1 mumol/L) increased [Ca2+]i from 68 to 241 nmol/L, and to 458 (P < 0.01) and 1006 nmol/L (P < 0.01), respectively, when 1.5 mmol/L and 3.0 mmol/L extracellular Ca2+ was reintroduced. Furthermore, the change in [Ca2+]i was observed with verapamil (5 micromol/L), La3+ (1 mmol/L) or KCl (40 mmol/L) in the bathing solution. These channels were sensitive to La3+ (P < 0.01), insensitive to verapamil, and voltage independent. In isolated distal colons we found that in normal Krebs solution, contraction induced by acetylcholine (ACh) was partially inhibited by verapamil, and the inhibitory rate was 41% (P < 0.05). On the other hand, in Ca2+-free Krebs solution, ACh induced transient contraction due to Ca2+ release from the intracellular stores. The transient contraction lasted until the Ca2+ store was depleted. Restoration of extracellular Ca2+ in the presence of atropine produced contraction, mainly due to Ca2+ influx. Such contraction was not inhibited by verapamil, but was decreased by La3+ (50 micromol/L) from 0.96 to 0.72 g (P < 0.01). CONCLUSION: The predominant source of activator Ca2+ for the contractile response to agonist is extracellular Ca2+, and intracellular Ca2+ has little role to play in mediating excitation-contraction coupling by agonists in rat distal colon smooth muscle in vitro. The influx of extracellular Ca2+ is mainly mediated through voltage-, receptor- and store-operated Ca2+ channels, which can be used as an alternative to develop new drugs targeted on the dysfunction of digestive tract motility.

[EEG characteristics of medial prefrontal cortex in rats with morphine dependent place preference under shuttling condition].

OBJECTIVE: To study the correlation between EEG characteristics of medial prefrontal cortex (mPFC) and drug-seeking behavior of rats with morphine dependent place preference under shuttling condition. METHODS: Forty rats were randomly divided into four groups (n = 10): morphine PL group, NS PL group, morphine IL group and NS IL group. After embeding the electrode in prelimbic (PL) or infralimbic (IL) cortex of each group by brain stereotaxic operation, the model of morphine dependent conditioned place preference (CPP) in rats was established. The differences of EEG wave percentage in mPFC were telemetered and analyzed when rats shuttled before and after the model. RESULTS: After the model, the withdrawal symptoms were evident in morphine PL and IL group, and the activity time and distance in white box were increased obviously. Compared with control group, after the model, the EEG in morphine PL group showed that: when the rats shuttled to white box, 8 wave decreased obviously, P wave increased obviously. When the rats shuttled to black box, brain waves showed opposite changes. The EEG in morphine IL group showed that: when the rats shuttled to white box, a wave increased obviously, P and a wave decreased obviously. When the rats shuttled to black box, the brain wave had no significant differences compared with control group. CONCLUSION: The EEG changes are different in PL and IL cortex of morphine CPP rats under shuttling condition, and the EEG changes are also different when rats shuttling to white or black box. There is possibly different mechanism, when different drug-seeking environmental cues caused EEG changes in different regions of mPFC.

[Changes of theta oscillation of prelimbic cortex in heroin-induced CPP rats].

OBJECTIVE: To investigate the relationship between the changes of neural oscillations and the drug-seeking motivation,record the telemetric local field potentials (LFPs) of the prelimbic cortex (PrL) in the latency of drug-seeking behavior of conditioned place preference (CPP) rats induced by heroin. METHODS: The recording electrode was stereotactically implanted intothe PrL cortex of rats. The animals were then randomly divided into operation-only control and heroin-induced CPP groups, respectively. A CPP video system in combination with awireless telemetry device was used for recording LFPs when the rats shuttled between black-white chamber for drug-seeking. The LFPs were analyzed by fast Fourier transform (FFT) and wavelet packet extraction. RESULTS: Compared with operation-only control group, the LFPs recorded in PrL area of heroin-induced CPP group of rat during black-white chamber shuttling showed that the percentage of θ rhythm were increased in right and left PrL, the percentage of γ3 rhythm was increased in left PrL, the phase-amplitude coupling of θ and γ3 was increased in left PrL. After MK-801 Maleate micro injection to PrL area,drug-seeking behavior of rat was markedly reduced and the percentage of θ oscillation was depressed,the phase-amplitude coupling of θ and γ3 was depressed in left PrL compared with operation-only control group. CONCLUSIONS: These results suggest that increase of θ oscillations of PrL area may be related to the drug-seeking motivation and behavior launching in heroin-induced CPP groups of rat. The changes of θ oscillations also have close relationship with glutamatergic neuron and the receptor of it on PrL area.

[The changes of electric shock avoidance response and local field potentials on hippocampal CA3 region of the adolescent rats with high fat feeding].

OBJECTIVE: To investigate the changes of shock avoidance response in Y maze and the real-time local field potentials (LFPs) on hippocampal CA3 region in adolescent rats with high fat feeding. METHODS: The juvenile rats of weaning 1 week were fed separately on basic feed (BF) and high fat diet (HFD) for 4 weeks until the puberty. Using the electric shock avoidance training method, the relevant parameters of reaching the learning standard of two groups of rats were recorded, and the LFPs of CA3 region in hippocampus were explored simultaneously by wireless telemetry. RESULTS: Compared with the BF group, the body weight of HFD rats were increased significantly(P<0.05), the rats percentage of reaching the learning standard within 1 to 2 days and the various parameters of shock avoidance recorded in training were all superior to those of BF group rat,the LFP rhythm of bilateral hippocampal CA3 region appeared to the desynchronizd fast wave. The θ and γ1 rhythms of right hippocampal CA3 region shown synchronous increase, but there was no coupling formation in phase-amplitude of the θ and γ1 rhythms. CONCLUSIONS: From juvenile to adolescent with HFD intake, the adolescent rat gained an increase significantly in weight,but the ability of shock avoidance and the function of hippocampus-dependent spatial cognition in Y maze had not be expected decline.

[Wireless telemetry electrical activity of nucleus accumbens shell in morphine-induced CPP rats].

OBJECTIVE: To analyse the relationship between the electrical activity changes of nucleus accumbens (NAc) shell and the drug-seeking behavior by recording NAc shell electrical activity in conditioned place preference (CPP) rats induced by morphine. METHODS: Forty SD rats were randomly divided into operation-only control group and the morphine-induced CPP group after stereotaxic electrode was buried on rats NAc shell and the latter group was used to establish the morphine CPP model(n = 20). A CPP video system combining with the technique of electrical activity wireless telemetry was used in the study. The NAc electrical activity from each group of rats was recorded by wireless telemetry respectively, which included staying in black or white chamber of video box, shuttling between black-white chambers and between white-black chambers. The electrical activity differences were analyzed by the percentage of each wave. RESULTS: When the morphine-induced rats staying in black chamber, compared with the operation-only control group, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased(P < 0.05), meanwhile, those of 10 - 20 Hz and 30 - 40 Hz were reduced(P < 0.05, P < 0.01); when the morphine-induced rats staying in white chamber, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz and 30 - 40 Hz were increased(P < 0.05 , P < 0.01) , that of 10 - 20 Hz was reduced(P < 0.05 , P < 0. 01); when the morphine-induced rats in black- white shuttling status, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased(P <0.05, P <0.01), that of 10- 30 Hz was reduced( P <0.05); and in the white-black shuttling status, the electrical activity showed that the percentage of 0 - 10 Hz was reduced(P <0.05), that of 10 - 30 Hz was increased(P < 0.05) ; the electrical activity was further compared between staying status and shuttling status in the morphine-induced CPP group. There was no significant difference of electrical activity between the rats in white-black shuttling status and staying in white chamber. However, when rats in black-white shuttling status, compared with staying in black chamber, the electrical activity showed that the percentage of 0 - 10 Hz and 40 - 50 Hz were increased(P < 0.05), meanwhile, those of 10 - 20 Hz and 30 - 40 Hz were reduced(P <0.05). CONCLUSION: The electrical activity changes of NAc shell in morphine-induced CPP rats were different from those of the operation-only control group, and these changes might be associated to the rat's drug-seeking behavior.

[A wireless telemetry study on the electrical activity in nucleus accumbens of heroin-induced place preference rats].

OBJECTIVE: To analyze the electrical activity property changes in nucleus accumbens (NAc) of heroin-induced conditioned place preference (CPP) rats during different stages of heroin dependence and to explore NAc's roles in the formation of drug dependence. METHODS: Recording electrodes were bilaterally embedded into the NAcs of rats with the aid of stereotaxic apparatus, followed by establishment of heroin-dependent rat model. The NAc electrical activity during 3 different stages of heroin dependence, including heroin pre-exposure, immediate post-exposure and heroin withdrawal, were respectively recorded using EEG wireless telemetry techniques. The frequency distribution (ranging from 0.5 to 30 Hz) and the amplitude of NAc electrical activity were analyzed and measured. RESULTS: Heroin-dependent rat models were successfully established and their withdrawal symptoms were evident. All rats showed a conditioned place preference (CPP) for the white box after 5-10 days of heroin-exposure, and displayed a maximum withdrawal symptoms on 2d after heroin- withdrawal. During all statges of heroin-dependence, the NAc electrical activity contained the highest proportion of delta rhythm and the lowest proportion of alpha2 rhythm. The discharge frequence band was similar across different stages. There was a significantly increased ratio of low-frequency discharges (delta rhythm) and decreased ratio of high-frequency discharges (beta rhythm) in NAc of rats during the immediate post- heroin exposure stage when compared with that during pre-exposure and heroin withdrawal stages. During the withdrawal stage, the ratio of at rhythm was significantly lower than during pre- and post-heroin exposure stages (P < 0.01). Further, the mean discharge amplitude in NAcs during immediate post-exposure and withdrawal stages was significantly increased relative to pre-exposure stage. However, the mean discharge amplitude during heroin withdrawal stage was significantly lower than during immediate post-exposure stage. CONCLUSION: The electrical activity properties in rat NAcs showed a significant change during different stages of heroin-dependence, which suggested that neuronal activities in NAcs might contribute to the modulation of drug-dependence.

Comparison of corneal biomechanical parameters between keratoconus and laser corneal refractive surgery / 眼科新进展

Objective To measure biomechanical parameters of the cornea after keratoconus and laser corneal refractive surgery by Scheimpflug noncontact tonometry (Corvis ST),and analyze the changes and differences in these parameters.Methods From April 2011 to November 2016,63 patients (96 eyes) with clinically diagnosed as keratoconus were selected as the keratoconus group,and 60 patients (120 eyes) underwent laser corneal refractive surgery between November 2016 to March 2017 were selected as postoperative cornea group,and totally 51 healthy person (102 eyes) who received physical examination during the same period were selected as healthy cornea group.Scheimpflug noncontact tonometry (Corvis ST) was performed to measure the length of appl 1,length of appl 2,velocity of appl 1,velocity of appl 2,maximum deformation amplitude,apex distance and radius of curvature in the three groups.Total comparison of biomechanical parameters was performed using ANOVA test among the three groups,while pairwise comparison was performed to analyze the difference of these parameters by SNK methods.Pearson or Spearman correlation analysis was applied to assess the differences in corneal morphological and biomechanical parameters.Results There was no significant difference in length of appl 1,length of appl 2 of the three groups (all P ＞ 0.05).And velocity of appl 1 in the keratoconus group was significantly higher than that of the healthy cornea group [(0.189 ± 0.230) m · s-1 vs.(0.151 ± 0.017)m · s-1] (P ＜ 0.05).As for velocity of appl 2,the keratoconus group was larger than the healthy cornea group,both which were larger than the postoperative cornea group,and the differences were significant (all P ＜ 0.05).And this was true of maximum deformation amplitude in the three groups,with the significant differences(all P ＜ 0.05).The apex distance in the keratoconus group was significantly longer than that in the healthy cornea group (P ＜ 0.05).The radius of curvature of the keratoconus group,postoperative cornea group and healthy cornea group were (5.696 ± 0.881) mm,(7.129 ± 0.681) mm and (7.012 ± 0.728) ram,respectively,which approached significant differences(all P ＜ 0.05).There was significant correlation between the anterior surface refractive power (Km) and apex distance and radius of curvature in the keratoconus group (r =-0.205,0.1 84;P =0.023,0.041),and maximum posterior surface elevation had a statistically significant correlation with velocity of appl 2,maximum deformation amplitude and radius of curvature (r =-0.579,-0.307,0.256,P =0.022,0.002,0.000).For the eyes in the postoperative cornea group,there were no significance correlation between the anterior surface refractive power (Km) and biomechanical properties (P ＞ 0.05),but significant correlation with length of appl 2 (r =-0.297,P =0.026).There were no significant correlation between maximum posterior surface elevation and biomechanical properties (P ＞ 0.05).Conclusion The corneal biomechanical parameters are decreased in eyes after keratoconus and laser corneal refractive surgery,and Corvis ST can become an auxiliary examination tool for earlier diagnosis of secondary keratoconus after corneal refractive surgery.

Effect of ceftriaxone on the intestinal epithelium and microbiota in neonatal mice / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the effect of ceftriaxone on the intestinal epithelium and microbiota in mice in the early-life stage, as well as the recovery of the intestinal epithelium and reconstruction of intestinal microbiota in adult mice.</p><p><b>METHODS</b>A total of 36 BALB/C neonatal mice were randomly divided into control group and experimental group, with 18 mice in each group. The mice in the experimental group were given ceftriaxone 100 mg/kg every day by gavage within 21 days after birth. Those in the control group were given an equal volume of normal saline by gavage. Immunohistochemistry was used to measure the expression of Ki67, Muc2, and ZO-1 in the intestinal epithelium. qPCR and next-generation sequencing were used to analyze the overall concentration and composition of fecal bacteria.</p><p><b>RESULTS</b>After 21 days of ceftriaxone intervention, the experimental group had a significant reduction in body weight, a significant reduction in the expression of Ki67 and ZO-1 and a significant increase in the expression of Muc2 in intestinal epithelial cells, a significant reduction in the overall concentration of fecal bacteria, and a significant increase in the diversity of fecal bacteria compared with the control group (P<0.05). Firmicutes was the most common type of fecal bacteria in the experimental group, and there were large amounts of Staphylococcus and Enterococcus. The experimental group had a certain degree of recovery of the intestinal epithelium, but there were still significant differences in body weight and the structure of intestinal microbiota between the two groups at 56 days after birth (P<0.05).</p><p><b>CONCLUSIONS</b>Early ceftriaxone intervention significantly affects the development of the intestinal epithelium and the construction of intestinal microbiota in the early-life stage. The injury of the intestinal microbiota in the early-life stage may continue to the adult stage and affect growth and development and physiological metabolism.</p>

EEG characteristics of medial prefrontal cortex in rats with morphine dependent place preference under shuttling condition / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the correlation between EEG characteristics of medial prefrontal cortex (mPFC) and drug-seeking behavior of rats with morphine dependent place preference under shuttling condition.</p><p><b>METHODS</b>Forty rats were randomly divided into four groups (n = 10): morphine PL group, NS PL group, morphine IL group and NS IL group. After embeding the electrode in prelimbic (PL) or infralimbic (IL) cortex of each group by brain stereotaxic operation, the model of morphine dependent conditioned place preference (CPP) in rats was established. The differences of EEG wave percentage in mPFC were telemetered and analyzed when rats shuttled before and after the model.</p><p><b>RESULTS</b>After the model, the withdrawal symptoms were evident in morphine PL and IL group, and the activity time and distance in white box were increased obviously. Compared with control group, after the model, the EEG in morphine PL group showed that: when the rats shuttled to white box, 8 wave decreased obviously, P wave increased obviously. When the rats shuttled to black box, brain waves showed opposite changes. The EEG in morphine IL group showed that: when the rats shuttled to white box, a wave increased obviously, P and a wave decreased obviously. When the rats shuttled to black box, the brain wave had no significant differences compared with control group.</p><p><b>CONCLUSION</b>The EEG changes are different in PL and IL cortex of morphine CPP rats under shuttling condition, and the EEG changes are also different when rats shuttling to white or black box. There is possibly different mechanism, when different drug-seeking environmental cues caused EEG changes in different regions of mPFC.</p>

Wireless telemetry electrical activity of nucleus accumbens shell in morphine-induced CPP rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To analyse the relationship between the electrical activity changes of nucleus accumbens (NAc) shell and the drug-seeking behavior by recording NAc shell electrical activity in conditioned place preference (CPP) rats induced by morphine.</p><p><b>METHODS</b>Forty SD rats were randomly divided into operation-only control group and the morphine-induced CPP group after stereotaxic electrode was buried on rats NAc shell and the latter group was used to establish the morphine CPP model(n = 20). A CPP video system combining with the technique of electrical activity wireless telemetry was used in the study. The NAc electrical activity from each group of rats was recorded by wireless telemetry respectively, which included staying in black or white chamber of video box, shuttling between black-white chambers and between white-black chambers. The electrical activity differences were analyzed by the percentage of each wave.</p><p><b>RESULTS</b>When the morphine-induced rats staying in black chamber, compared with the operation-only control group, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased(P < 0.05), meanwhile, those of 10 - 20 Hz and 30 - 40 Hz were reduced(P < 0.05, P < 0.01); when the morphine-induced rats staying in white chamber, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz and 30 - 40 Hz were increased(P < 0.05 , P < 0.01) , that of 10 - 20 Hz was reduced(P < 0.05 , P < 0. 01); when the morphine-induced rats in black- white shuttling status, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased(P <0.05, P <0.01), that of 10- 30 Hz was reduced( P <0.05); and in the white-black shuttling status, the electrical activity showed that the percentage of 0 - 10 Hz was reduced(P <0.05), that of 10 - 30 Hz was increased(P < 0.05) ; the electrical activity was further compared between staying status and shuttling status in the morphine-induced CPP group. There was no significant difference of electrical activity between the rats in white-black shuttling status and staying in white chamber. However, when rats in black-white shuttling status, compared with staying in black chamber, the electrical activity showed that the percentage of 0 - 10 Hz and 40 - 50 Hz were increased(P < 0.05), meanwhile, those of 10 - 20 Hz and 30 - 40 Hz were reduced(P <0.05).</p><p><b>CONCLUSION</b>The electrical activity changes of NAc shell in morphine-induced CPP rats were different from those of the operation-only control group, and these changes might be associated to the rat's drug-seeking behavior.</p>

Alteration of neural oscillations in hippocampal CA3 area in the fast avoidance response rat before and after electric shock avoidance training / 生理学报

The purpose of the present study is to explore the relationship of spatial learning ability and specific electrical activities of neural oscillations in the rat. The fast and general avoidance response groups were selected on the basis of the animals' responses to the electric shock in Y type maze, and their local field potentials (LFPs) of hippocampal CA3 area were recorded by wireless telemetry before and after shock avoidance training, respectively. The components of neural oscillations related to spatial identifying and learning ability were analyzed. The results showed that, compared with the general avoidance response group, the fast avoidance response group did not show any differences of LFPs in hippocampal CA3 area before electric shock avoidance trial, but showed significantly increased percentages of 0-10 Hz and 30-40 Hz rhythm in right hippocampal CA3 area after the shock avoidance training (P < 0.01 or P < 0.05). Fast Fourier transform showed that percentage increase of 0-10 Hz band occurred mainly in θ (3-7 Hz) frequency, and 30-40 Hz frequency change was equivalent to the γ1 band. Furthermore, compared with those before training, only the percentages of β, β2 (20-30 Hz) and γ1 rhythm increased (P < 0.01 or P < 0.05) in fast avoidance response rats after training, while the θ rhythm percentage remained unchanged. In contrast, θ rhythm percentage and the large amplitude (intensity: +2.5 - -2.5 db) θ waves in right CA3 area of general avoidance response rats were significantly reduced after training (P < 0.01). These results suggest that the increased percentages of β2 and γ1 rhythm and high-level (unchanged) percentage of θ rhythm in the right hippocampus CA3 area might be related to strong spatial cognition ability of fast avoidance response rats.

Crystallography of ATP hydrolysis mechanism in rat brain kinesin / 生物工程学报

Rat brain kinesin is a conventional kinesin that uses the energy from ATP hydrolysis to walk along the microtubule progressively. Studying how the chemical energy in ATP is utilized for mechanical movement is important to understand this moving function. The monomeric motor domain, rK354, was crystallized. An ATP analog, AMPPNP, was soaked in the active site. Comparing the complex structure of rK354 x AMPPNP and that of rK354ADP, a hypothesis is proposed that Glu237 in the Switch II region sensors the presence of gamma-phosphate and transfers the signal to the microtubule binding region.

Expression, purification and crystallization of rat brain kinesin / 生物工程学报

Kinesin is a motor protein that uses the energy from ATP hydrolysis to move along the microtubule system. To investigate how the chemical energy stored in ATP is converted to mechanical movement, the corresponding N-terminal region of rat brain kinesin was expressed in BL21-Codon Plus (DE3)-RP competent cells. After SP-cation exchange chromatography and size exclusion chromatography, the protein yield reached 10 mg/L culture with the purity above 95%. The purified protein had ATPase activity and specifically reacted with the kinesin antibody in the Western blotting analysis. The purified kinesin was crystallized under the following condition: 1.7 mol/L (NH4)2SO4, 500 mmol/L NaCl, 20% glycerol. The kinesin crystal can diffract up to 2.0 angstroms resolution.

Wavelet packet extraction and entropy analysis of telemetry EEG from the prelimbic cortex of medial prefrontal cortex in morphine-induced CPP rats / 生理学报

The purpose of the present study is to analyze the relationship between the telemetry electroencephalogram (EEG) changes of the prelimbic (PL) cortex and the drug-seeking behavior of morphine-induced conditioned place preference (CPP) rats by using the wavelet packet extraction and entropy measurement. The recording electrode was stereotactically implanted into the PL cortex of rats. The animals were then divided randomly into operation-only control and morphine-induced CPP groups, respectively. A CPP video system in combination with an EEG wireless telemetry device was used for recording EEG of PL cortex when the rats shuttled between black-white or white-black chambers. The telemetry recorded EEGs were analyzed by wavelet packet extraction, Welch power spectrum estimate, normalized amplitude and Shannon entropy algorithm. The results showed that, compared with operation-only control group, the left PL cortex's EEG of morphine-induced CPP group during black-white chamber shuttling exhibited the following changes: (1) the amplitude of average EEG for each frequency bands extracted by wavelet packet was reduced; (2) the Welch power intensity was increased significantly in 10-50 Hz EEG band (P < 0.01 or P < 0.05); (3) Shannon entropy was increased in β, γ₁, and γ₂waves of the EEG (P < 0.01 or P < 0.05); and (4) the average information entropy was reduced (P < 0.01). The results suggest that above mentioned EEG changes in morphine-induced CPP group rat may be related to animals' drug-seeking motivation and behavior launching.

A wireless telemetry study on the electrical activity in nucleus accumbens of heroin-induced place preference rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To analyze the electrical activity property changes in nucleus accumbens (NAc) of heroin-induced conditioned place preference (CPP) rats during different stages of heroin dependence and to explore NAc's roles in the formation of drug dependence.</p><p><b>METHODS</b>Recording electrodes were bilaterally embedded into the NAcs of rats with the aid of stereotaxic apparatus, followed by establishment of heroin-dependent rat model. The NAc electrical activity during 3 different stages of heroin dependence, including heroin pre-exposure, immediate post-exposure and heroin withdrawal, were respectively recorded using EEG wireless telemetry techniques. The frequency distribution (ranging from 0.5 to 30 Hz) and the amplitude of NAc electrical activity were analyzed and measured.</p><p><b>RESULTS</b>Heroin-dependent rat models were successfully established and their withdrawal symptoms were evident. All rats showed a conditioned place preference (CPP) for the white box after 5-10 days of heroin-exposure, and displayed a maximum withdrawal symptoms on 2d after heroin- withdrawal. During all statges of heroin-dependence, the NAc electrical activity contained the highest proportion of delta rhythm and the lowest proportion of alpha2 rhythm. The discharge frequence band was similar across different stages. There was a significantly increased ratio of low-frequency discharges (delta rhythm) and decreased ratio of high-frequency discharges (beta rhythm) in NAc of rats during the immediate post- heroin exposure stage when compared with that during pre-exposure and heroin withdrawal stages. During the withdrawal stage, the ratio of at rhythm was significantly lower than during pre- and post-heroin exposure stages (P < 0.01). Further, the mean discharge amplitude in NAcs during immediate post-exposure and withdrawal stages was significantly increased relative to pre-exposure stage. However, the mean discharge amplitude during heroin withdrawal stage was significantly lower than during immediate post-exposure stage.</p><p><b>CONCLUSION</b>The electrical activity properties in rat NAcs showed a significant change during different stages of heroin-dependence, which suggested that neuronal activities in NAcs might contribute to the modulation of drug-dependence.</p>