BACKGROUND: This study aimed to explore the effects of norepinephrine on the potassium currents of rat medial vestibular nuclear neurons by using the whole-cell patch clamp technique. METHODS: Sprague-Dawley rats aged 14 to 16 days were anesthetized with ether and decapitated. After enzymatic digestion, the portion of the medial vestibular nucleus neurons were obtained by micropunching. The dissociated neurons were transferred into a recording chamber mounted on an inverted microscope and potassium currents were recorded by standard patch-clamp techniques under voltage-clamp modes. RESULTS: Norepinephrine inhibited the whole potassium currents of the medial vestibular nuclear neurons. Outward potassium currents were more suppressed in 4 mM 4-aminopyridine and norepinephrine added solutions than 4 mM 4-aminopyridine only, but were not suppressed in 10 mM tetraethylammonium and norepinephrine added solutions compared to 10 mM tetraethylammonium only. CONCLUSIONS: These results suggest that norepinephrine blocks the delayed rectifier potassium channels in medial vestibular nuclear neurons.
4-Aminopyridine ; Animals ; Delayed Rectifier Potassium Channels ; Digestion ; Ether ; Neurons* ; Norepinephrine* ; Patch-Clamp Techniques ; Potassium* ; Rats* ; Rats, Sprague-Dawley ; Tetraethylammonium ; Vestibular Nuclei

Coeruleo-vestibular pathway which connects locus coeruleus and vestibular nuclei is noradrenergic. This study was designed to elucidate the effects of phenylephrine on the spontaneous activity of acutely isolated medial vestibular nuclear neurons of rat by whole-cell patch-clamp technique. Sprague-Dawley rats, aged 14 to 16 days, were used. After enzymatic digestion, dissociated medial vestibular neurons were transferred to a recording chamber mounted on an inverted microscope, and spontaneous action potentials were recorded by standard patch-clamp techniques. In current-clamp mode, the frequency of spontaneous action potential of medial vestibular nuclear neurons was decreased by phenylephrine (n=15). Phenylephrine increased the amplitude of afterhyperpolarization without changes in the resting membrane potential and spike width. In voltage-clamp mode, the whole potassium currents of the medial vestibular nuclear neurons were increased by phenylephrine (n=12). These experimental results suggest that alpha-receptor mediates the inhibitory effects on the neuronal activity of the medial vestibular nuclear neuron.
Action Potentials ; Animals ; Digestion ; Locus Coeruleus ; Membrane Potentials ; Neurons* ; Patch-Clamp Techniques ; Phenylephrine* ; Potassium ; Rats* ; Rats, Sprague-Dawley ; Vestibular Nuclei

This survey was performed to analyze the usability of the third edition of the Korean breast cancer clinical practice guidelines (KBCCPG) in clinical practice. We made a questionnaire composed of 18 general and 82 specific questions regarding benign breast disease (B; 1 question); non-invasive disease (N; 12 questions); early-stage disease (E; 26 questions); advanced disease (A; 24 questions); and metastatic (M) breast cancer-related problems (19 questions). A total of 100 questionnaires, with a link to an online survey, were delivered via e-mail to over 700 members of the Korean Breast Cancer Society (KBCS), and associated academy members, over 20 days between 26th February and 16th May 2010. Out of 270 respondents who read the e-mail, 96 answered the questionnaire. Participants included 87 surgical oncologists, 5 radiation oncologists, 2 oncoplastic surgeons, 1 pathologist, and 1 medical oncologist. The third KBCCPG were perceived as differing from the second guidelines in terms of the level of clinical evidence required before choosing a recommendation. For the progress of the KBCCPG, the guideline committee should try to reinforce all courses of guideline development with several elements including data from clinical trials of Korean breast cancer patients, securing a multidisciplinary approach, developing consistent and reasonable processes for each step of the revision of the guidelines, induction of liberal scientific and ethical discussion about all issues with all KBCS members. The cost-effectiveness of healthcare and the logical development of the KBCCPG would also be ensured. Timely updates of the clinical guidelines for breast cancer treatment are essential to facilitate optimal decision-making in daily practice, and to ensure adequate patient feedback.
Aluminum Hydroxide ; Breast ; Breast Diseases ; Breast Neoplasms ; Carbonates ; Surveys and Questionnaires ; Delivery of Health Care ; Dietary Sucrose ; Electronic Mail ; Humans ; Korea ; Logic