• 제목/요약/키워드: Action Potential

검색결과 1,308건 처리시간 0.027초

어린이집 1세반 영아와 그림책의 만남: 내부작용을 통한 의미생성의 관점에서 (The Encounter between Infants in a 1-Year-Old Daycare Class and Picture Books: From the Perspective of Meaning-making through Intra-action)

  • 이승연;김유미
    • 한국보육지원학회지
    • /
    • 제20권2호
    • /
    • pp.59-81
    • /
    • 2024
  • Objective: This study aims to explore the intra-action between infants and picture book reading in a daycare setting, aiming to gain new insight into infants' reading experiences. Methods: The participants in the study were 12 infants from the Bluebird Class (1-year-old) at A Daycare Center. To comprehensively examine the context and flow of the infants' experiences, participant observation was conducted during free play sessions, held three to five times a week, in the morning, from December 19, 2022, to February 17, 2023. Results: Firstly, infants engaged in the intra-action with symbols such as text, images, lines, colors, and latent narratives in picture books, spontaneously encountering meaning-making. Secondly, they explored the potential of materials such as their own bodies, the dacare classroom environment, and blocks, creating narratives through the process of 'becoming'. Thirdly, infants generated shared experiences by creating interactions within their relationships with others in the daycare class. Conclusion/Implications: This study highlights a shift in perspective, recognizing infants as active readers who construct their own understanding. Additionally, it underscores the significance of cultivating an infant-centered environment and the meaningful role of teachers in supporting and facilitating such an environment.

Analysis of interaction between intracellular spermine and transient receptor potential canonical 4 channel: multiple candidate sites of negatively charged amino acids for the inward rectification of transient receptor potential canonical 4

  • Kim, Jinsung;Moon, Sang Hui;Kim, Taewook;Ko, Juyeon;Jeon, Young Keul;Shin, Young-Cheul;Jeon, Ju-Hong;So, Insuk
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제24권1호
    • /
    • pp.101-110
    • /
    • 2020
  • Transient receptor potential canonical 4 (TRPC4) channel is a nonselective calcium-permeable cation channels. In intestinal smooth muscle cells, TRPC4 currents contribute more than 80% to muscarinic cationic current (mIcat). With its inward-rectifying current-voltage relationship and high calcium permeability, TRPC4 channels permit calcium influx once the channel is opened by muscarinic receptor stimulation. Polyamines are known to inhibit nonselective cation channels that mediate the generation of mIcat. Moreover, it is reported that TRPC4 channels are blocked by the intracellular spermine through electrostatic interaction with glutamate residues (E728, E729). Here, we investigated the correlation between the magnitude of channel inactivation by spermine and the magnitude of channel conductance. We also found additional spermine binding sites in TRPC4. We evaluated channel activity with electrophysiological recordings and revalidated structural significance based on Cryo-EM structure, which was resolved recently. We found that there is no correlation between magnitude of inhibitory action of spermine and magnitude of maximum current of the channel. In intracellular region, TRPC4 attracts spermine at channel periphery by reducing access resistance, and acidic residues contribute to blocking action of intracellular spermine; channel periphery, E649; cytosolic space, D629, D649, and E687.

Contractile and Electrical Responses of Guinea-pig Gastric Smooth Muscle to Bradykinin

  • Kim, Chul-Soo;Jun, Jae-Yeoul;Kim, Sung-Joon;So, In-Suk;Kim, Ki-Whan
    • The Korean Journal of Physiology
    • /
    • 제29권2호
    • /
    • pp.233-241
    • /
    • 1995
  • The nonapeptide bradykinin has been shown to exhibit an array of biological activities including relaxation/contraction of various smooth muscles. In order to investigate the effects of bradykinin on the contractility and the electrical activity of antral circular muscle of guinea-pig stomach, the isometric contraction and membrane potential were recorded. Also, using standard patch clamp technique, the $Ca^{2+}-activated$ K currents were recorded to observe the change in cytosolic $Ca^{2+}$ concentration. $0.4 {\mu}M$ bradykinin induced a triphasic contractile response (transient contraction-transient relaxation-sustained contraction) and this response was unaffected by pretreatment with neural blockers (tetrodotoxin, atropine and guanethidine) or with apamin. Bradykinin induced hyperpolarization of resting membrane potential and enhanced the amplitude of slow waves and spike potentials. The enhancement of spike potentials was blocked by neural blockers. Both the bradykinin-induced contractions and changes in membrane potential were reversed by the selective $B_2$-receptor antagonist $(N{\alpha}-adamantaneacetyl-_{D}-Arg-[Hyp, Thy,_{D}-Phe]-bradykinin)$. In whole-cell patch clamp experiment, we held the membrane potential at -20 mV and spontaneous and transient changes of Ca-activated K currents were recorded. Bradykinin induced a large transient outward current, consistent with a calcium-releasing action of bradykinin front the intracellular calcium pool, because such change was blocked by pretreatment with caffeine. Bradykinin-induced contraction was also blocked by pretreatment with caffeine. From these results, it is suggested that bradykinin induces a calciumrelease and contraction through the $B_{2}$ receptor of guinea-pig gastric smooth muscle. Enhancement of slow wave activity is an indirect action of bradykinin through enteric nerve cells embedded in muscle strip.

  • PDF

경락상태진단을 위한 경락의 전위변화 분석 (Analysis of Meridians Potential Change for Meridians State Diagnosis)

  • 이용흠;고수복;정석준;정동명
    • 대한의용생체공학회:의공학회지
    • /
    • 제23권5호
    • /
    • pp.405-412
    • /
    • 2002
  • 경락에서의 침구효과 원리는 침 자극이 인체의 저하된 기능상태로부터 각성상태, 응급상태, 국부적 쇼크 상태로 만들어줌으로써 인체의 전반적 생리기능이 새로운 평형을 이룰 수 있도록 하는데 있다. 그러나, 서양의학에서는 침구치료효과를 시술자의 생체에너지(기) 전달에 의한 효과보다는 단순한 침자극에 의한 신경-내분비-면역 계통의 작용과 반응으로 간주하고있다. 따라서 침구치료의 효과가 침 자극에 의한 경락의 작용임을 확인하고, 시술방법에 따른 전위 변화를 분석하기 위해서 경혈과 비경혈, 절연자침과 비절연자침, 보법과 사법으로 자극했을 때의 전위변화를 측정한 결과, 각각 다른 반응이 나타났다. 이는 동일 경락에서 침구의 작용효과는 단순한 침 자극에 의한 효과뿐만 아니라, 시술자의 생체에너지 전달에 의해 복합적으로 반응할 수 있음을 의미한다. 임상실험을 분석한 결과, 시술방법에 따른 경락에서의 전위 변화는 해당 경락의 허실과 해당장기의 건강상태에 따라 다르게 나타나고 있어서, 경락의 허실상태를 진단할 수 있는 진단 파라메터로서의 유의성을 확인하였다.

해마 theta 리듬과 pyramidal neuron의 세포내 특성과의 상관관계 (CORRELATIONS BETWEEN HIPPOCAMPAL THETA RHYTHM AND INTRACELLULAR CHARACTERISTICS OF PYRAMIDAL NEURONS)

  • 권오흥;김영진;남순현;김현정;이만기;조진화;최병주
    • 대한소아치과학회지
    • /
    • 제25권4호
    • /
    • pp.671-682
    • /
    • 1998
  • Electrophysiological phenomena of pyramidal cells in the CA1 area of the dorsal hippocampus were recorded from and filled with neurobiotin in anesthetized rats. The electropharmacological properties of membrane as well as the cellular-synaptic generation of rhythmic slow activity (theta) were examined. The intracellular response characteristics of these pyramidal cells were distinctly different from responses of interneurons. Pyramidal cells had a high resting membrane potential, a low input resistance, and a large amplitude action potential. A afterhyperpolarization was followed a single action potential. Most of pyramidal cells did not display a spontaneous firing. Pyramidal cells displayed weak inward rectification and anodal break excitation. The slope of the frequency-current relation was 53.4 Hz/nA for the first interspike interval and 15.9 Hz/nA for the last intervals, suggesting the presence of spike frequency adaptation. Neurobiotin-filled neurons showed pyramidal morphology. Cells were generally bipolar dendritc processes ramifying in stratum lacunosum-moleculare, radiatum, and oriens. Commissural stimulation discharged pyramidal cells, followed by excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs). The frequency of theta-related membrane potential oscillation was voltage-independent in pyramidal neurons. At strong depolarization levels (less than 30 mV) pyramidal cells emitted sodium spike oscillation, phase-locked to theta. The observations provide direct evidence that theta-related rhythmic hyperpolarization of principal cells is brought by the rhythmically discharging interneurons. Furthermore, the findings in which interneurons were also paced by rhythmic inhibitory postsynaptic potentials during theta suggest that they were periodically hyperpolarized by their GABAergic septal afferents.

  • PDF

Dependence Potential of Quetiapine: Behavioral Pharmacology in Rodents

  • Cha, Hye Jin;Lee, Hyun-A;Ahn, Joon-Ik;Jeon, Seol-Hee;Kim, Eun Jung;Jeong, Ho-Sang
    • Biomolecules & Therapeutics
    • /
    • 제21권4호
    • /
    • pp.307-312
    • /
    • 2013
  • Quetiapine is an atypical or second-generation antipsychotic agent and has been a subject of a series of case report and suggested to have the potential for misuse or abuse. However, it is not a controlled substance and is not generally considered addictive. In this study, we examined quetiapine's dependence potential and abuse liability through animal behavioral tests using rodents to study the mechanism of quetiapine. Molecular biology techniques were also used to find out the action mechanisms of the drug. In the animal behavioral tests, quetiapine did not show any positive effect on the experimental animals in the climbing, jumping, and conditioned place preference tests. However, in the head twitch and self-administration tests, the experimental animals showed significant positive responses. In addition, the action mechanism of quetiapine was found being related to dopamine and serotonin release. These results demonstrate that quetiapine affects the neurological systems related to abuse liability and has the potential to lead psychological dependence, as well.

Potential Moracin M Prodrugs Strongly Attenuate Airway Inflammation In Vivo

  • Lee, Jongkook;Mandava, Suresh;Ahn, Sung-Hoon;Bae, Myung-Ae;So, Kyung Soo;Kwon, Ki Sun;Kim, Hyun Pyo
    • Biomolecules & Therapeutics
    • /
    • 제28권4호
    • /
    • pp.344-353
    • /
    • 2020
  • This study aims to develop new potential therapeutic moracin M prodrugs acting on lung inflammatory disorders. Potential moracin M prodrugs (KW01-KW07) were chemically synthesized to obtain potent orally active derivatives, and their pharmacological activities against lung inflammation were, for the first time, examined in vivo using lipopolysaccharide (LPS)-induced acute lung injury model. In addition, the metabolism of KW02 was also investigated using microsomal stability test and pharmacokinetic study in rats. When orally administered, some of these compounds (30 mg/kg) showed higher inhibitory action against LPS-induced lung inflammation in mice compared to moracin M. Of them, 2-(3,5-bis((dimethylcarbamoyl)oxy)phenyl)benzofuran-6-yl acetate (KW02) showed potent and dose-dependent inhibitory effect on the same animal model of lung inflammation at 1, 3, and 10 mg/kg. This compound at 10 mg/kg also significantly reduced IL-1β concentration in the bronchoalveolar lavage fluid of the inflamed-lungs. KW02 was rapidly metabolized to 5-(6-hydroxybenzofuran-2-yl)-1,3-phenylene bis(dimethylcarbamate) (KW06) and moracin M when it was incubated with rat serum and liver microsome as expected. When KW02 was administered to rats via intravenous or oral route, KW06 was detected in the serum as a metabolite. Thus, it is concluded that KW02 has potent inhibitory action against LPS-induced lung inflammation. It could behave as a potential prodrug of moracin M to effectively treat lung inflammatory disorders.

토끼 동방결절에서의 완만내향전류$(i_{si})$에 관한 연구 (Properties of Slow Inward Current in the Rabbit Sinoatrial Node)

  • 안광필;이영균;엄융의;김우겸
    • The Korean Journal of Physiology
    • /
    • 제20권2호
    • /
    • pp.165-174
    • /
    • 1986
  • The voltage clamp studies were undertaken to elucidate the properties of the slow inward current, $i_{si}$, in the small preparations of the rabbit sinoatrial node. The slow inward current, $i_{si}$, which is known to be responsible for the late one-third of pacemaker potential and whole range of upstroke phase of action potential was analysed with the effects of isoprenaline, cobalt, ouabain and higenamine. The results obtained are as follows; 1) Voltage of SA node preparation was held at zero current level, usually-40mV and the slow inward current, $i_{si}$, was activated by depolarizing clamp pulses. Peak values of $i_{si}$, in steady state were at $-10{\pm}0mV$ in most preparations. 2) Isoprenaline, ${\beta}-agonist$ increased $i_{si}$ and no shift was noticed in voltage-dependency. 3) Cobalt ion in the concentration of 1 mM abolished is, in entire range of membrane potential and the difference of two current levels before and after $Co^{2+}$ treatment could be considered as pure $i_{si}$ magnitude. 4) In the therapeutic concentration of ouabain $(5{\times}10^{-8}M)$ slightly increased is, and reduced the time to reach the peak value. 5) Higenamine $(10^{-6}M)$ changed the configurations of action potential (i. e. rapid upstroke phase and notch in the spike) and increase spontaneous rate. It also increased is, and the effect of higenamine was blocked ${\beta}-blocker$, propranolol $(10^{-6}M)$.

  • PDF

Ginsenosides from Korean Red Ginseng ameliorate lung inflammatory responses: inhibition of the MAPKs/NF-κB/c-Fos pathways

  • Lee, Ju Hee;Min, Dong Suk;Lee, Chan Woo;Song, Kwang Ho;Kim, Yeong Shik;Kim, Hyun Pyo
    • Journal of Ginseng Research
    • /
    • 제42권4호
    • /
    • pp.476-484
    • /
    • 2018
  • Background: Korean Red Ginseng (steamed and dried white ginseng, Panax ginseng Meyer) is well known for enhancing vital energy and immune capacity and for inhibiting cancer cell growth. Some clinical studies also demonstrated a therapeutic potential of ginseng extract for treating lung inflammatory disorders. This study was conducted to establish the therapeutic potential of ginseng saponins on the lung inflammatory response. Methods: From Korean Red Ginseng, 11 ginsenosides (Rb1, Rb2, Rb3, Rc, Rd, Re, Rf, Rg1, Rg2, Rg3, and Rh2) were isolated. Their inhibitory potential and action mechanism were evaluated using a mouse model of lung inflammation, acute lung injury induced by intranasal lipopolysaccharide administration. Their anti-inflammatory activities were also examined in lung epithelial cell line (A549) and alveolar macrophage (MH-S). Results: All ginsenosides orally administered at 20 mg/kg showed 11.5-51.6% reduction of total cell numbers in bronchoalveolar lavage fluid (BALF). Among the ginsenosides, Rc, Re, Rg1, and Rh2 exhibited significant inhibitory action by reducing total cell numbers in the BALF by 34.1-51.6% (n = 5). Particularly, Re showed strong and comparable inhibitory potency with that of dexamethasone, as judged by the number of infiltrated cells and histological observations. Re treatment clearly inhibited the activation of mitogen-activated protein kinases, nuclear factor-${\kappa}B$, and the c-Fos component in the lung tissue (n = 3). Conclusion: Certain ginsenosides inhibit lung inflammatory responses by interrupting these signaling molecules and they are potential therapeutics for inflammatory lung diseases.

The Amplification of the Morse Codes, which Cho Ji-Hoon's Poem Silent Night 1 Leaves in the Human Body

  • Park, In-Kwa
    • International Journal of Advanced Culture Technology
    • /
    • 제6권1호
    • /
    • pp.42-49
    • /
    • 2018
  • In this study, we tried to reveal the state of stillness of Cho Ji-Hoon's poem "Silent Night 1" as a healing modifier. The language of poem is synaptically linked to the calmness emotion of the human body, seeking a principle that leads to a state of healing. Therefore, this study was carried out for the purpose of applying the principle to literary therapy program. The silent signal embedded in the poem is encoded into the signals of the sound as it is synapsed to the human body. Encoding of auditory nerves by poem lines is like a Morse code that word and word leave in the human body. The action potential of the auditory nerve is further activated by the potential difference between the word and the word represented by the neural network, such as a Morse code, which is accessed to the human body by such a path. There is worked as amplified potential difference between the words perceived by a sound which is synapsed to the human body and by a silence which is synapsed to the human body. The phenomenon of the words approaching the human body and setting the absence of sound and amplifying the sound is because the words amplifies the Morse codes in the human neural network. At this time, the signals overlap each other. Thereby this poem is increasing the amplitude of the sound. This overlapping of auditory signals appears and amplifies the catharsis. If this Cho Ji-Hoon Poem's principle is applied to literary therapy program in the future, more effective treatment will be done.