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2.
Article in English | MEDLINE | ID: mdl-36288796

ABSTRACT

PURPOSE: The literature suggests that the ability to numerate cannot be fully understood without accounting for the social context in which mathematical activity is represented. Team-based learning (TBL) is an andragogical approach with theoretical links to sociocultural and community-of-practice learning. This study aimed to quantitatively explore the impact of TBL instruction on numeracy development in 2 cohorts of pharmacy students and identify the impact of TBL instruction on numeracy development from a social perspective for healthcare education. METHODS: Two cohorts of students were administered the Health Science Reasoning Test-Numeracy (HSRT-N) before beginning pharmacy school. Two years after using TBL as the primary method of instruction, both comprehensive and domain data from the HSRT-N were analyzed. RESULTS: In total, 163 pharmacy student scores met the inclusion criteria. The students' numeracy skills measured by HSRT-N improved after 2 years of TBL instruction. CONCLUSION: Numeracy was the most significantly improved HSRT-N domain in pharmacy students following two years of TBL instruction. Although a closer examination of numeracy development in TBL is warranted, initial data suggest that TBL instruction may be an adequate proxy for advancing numeracy in a cohort of pharmacy students. TBL may encourage a social practice of mathematics to improve pharmacy students' ability to numerate critically.


Subject(s)
Students, Pharmacy , Humans , Longitudinal Studies , Learning , Cohort Studies , Problem Solving , Problem-Based Learning , Educational Measurement/methods
3.
Cells ; 10(8)2021 07 31.
Article in English | MEDLINE | ID: mdl-34440722

ABSTRACT

Human stem cell-derived neurons are increasingly considered powerful models in drug discovery and disease modeling, despite limited characterization of their molecular properties. Here, we have conducted a detailed study of the properties of a commercial human induced Pluripotent Stem Cell (iPSC)-derived neuron line, iCell [GABA] neurons, maintained for up to 3 months in vitro. We confirmed that iCell neurons display neurite outgrowth within 24 h of plating and label for the pan-neuronal marker, ßIII tubulin within the first week. Our multi-electrode array (MEA) recordings clearly showed neurons generated spontaneous, spike-like activity within 2 days of plating, which peaked at one week, and rapidly decreased over the second week to remain at low levels up to one month. Extracellularly recorded spikes were reversibly inhibited by tetrodotoxin. Patch-clamp experiments showed that iCell neurons generated spontaneous action potentials and expressed voltage-gated Na and K channels with membrane capacitances, resistances and membrane potentials that are consistent with native neurons. Our single neuron recordings revealed that reduced spiking observed in the MEA after the first week results from development of a dominant inhibitory tone from GABAergic neuron circuit maturation. GABA evoked concentration-dependent currents that were inhibited by the convulsants, bicuculline and picrotoxin, and potentiated by the positive allosteric modulators, diazepam, chlordiazepoxide, phenobarbital, allopregnanolone and mefenamic acid, consistent with native neuronal GABAA receptors. We also show that glycine evoked robust concentration-dependent currents that were inhibited by the neurotoxin, strychnine. Glutamate, AMPA, Kainate and NMDA each evoked concentration-dependent currents in iCell neurons that were blocked by their selective antagonists, consistent with the expression of ionotropic glutamate receptors. The NMDA currents required the presence of the co-agonist glycine and were blocked in a highly voltage-dependent manner by Mg2+ consistent with the properties of native neuronal NMDA receptors. Together, our data suggest that such human iPSC-derived neurons may have significant value in drug discovery and development and may eventually largely replace the need for animal tissues in human biomedical research.


Subject(s)
Drug Discovery , Excitatory Amino Acid Agonists/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , GABAergic Neurons/drug effects , Induced Pluripotent Stem Cells/drug effects , Neural Stem Cells/drug effects , Cell Line , Dose-Response Relationship, Drug , GABAergic Neurons/metabolism , Humans , Induced Pluripotent Stem Cells/metabolism , Ion Channels/drug effects , Ion Channels/metabolism , Membrane Potentials , Neural Stem Cells/metabolism , Phenotype
4.
Am J Pharm Educ ; 85(1): 8414, 2021 01.
Article in English | MEDLINE | ID: mdl-34281824

ABSTRACT

This paper presents 10 key tips or recommendations for successful navigation of the promotion and tenure process. The 10 key tips are: know institutional expectations, develop an action plan at least two to three years in advance; identify your balance of teaching, scholarship, service; synergize activities and develop a niche; prioritize time to activities of high-impact to promotion and tenure; track achievements in the format expected for promotion and tenure application; seek out faculty guidance on promotion and tenure; meet with mentor(s) regularly to review progress; have a well-written personal statement; and have your final dossier reviewed by colleagues. Faculty members are more likely to be successful through timely and appropriate planning, balancing and synergizing activities, tracking activities and achievements, developing a well-written personal statement, and requesting help from experienced colleagues.


Subject(s)
Education, Pharmacy , Faculty, Pharmacy , Career Mobility , Faculty , Humans , Mentors
5.
Curr Pharm Teach Learn ; 13(2): 116-121, 2021 02.
Article in English | MEDLINE | ID: mdl-33454066

ABSTRACT

INTRODUCTION: Critical thinking is an important ability for pharmacists, but few studies have found improvements in pharmacy student critical thinking skills as a consequence of their education. Team-based learning (TBL) is an active learning strategy that encourages students to think critically to solve problems. The purpose of this study was to evaluate the impact of TBL on the critical thinking skills of pharmacy students. METHODS: One hundred ninety students from the first two cohorts at a pharmacy school were invited to participate. The Health Science Reasoning Test (HSRT) was administered prior to the first semester and after two years of the TBL-based pharmacy curriculum. Student's t-test was used for a pairwise analysis along with Welch's t-test for unequal variances when comparing HSRT score modulation. RESULTS: There was an overall increase in mean HSRT score. However, some participants (29%) with initially higher mean HSRT scores did not demonstrate an increase. Nearly all (99%) participants demonstrated improvements of one of the eight domains of critical thinking evaluated in the HSRT. This corresponded with an improvement in score of the majority of participants (n = 115). CONCLUSION: This study provides evidence that TBL improves critical thinking skills. More research is needed to identify the specific aspects of TBL that influence critical thinking.


Subject(s)
Education, Pharmacy , Students, Pharmacy , Educational Measurement , Humans , Learning , Schools, Pharmacy , Thinking
6.
Am J Pharm Educ ; 83(3): 7456, 2019 04.
Article in English | MEDLINE | ID: mdl-31065173

ABSTRACT

Objective. To characterize how virtual reality (VR) has been and is being used in pharmacy education, and evaluate the projected utility of VR technology in pharmacy education in the future. Findings. Virtual reality technology has been used in pharmacy education for many years to provide engaging learning experiences. Although these learning experiences were not available in the three-dimensional digital environments provided by current VR, they demonstrated improvements in learning. Recent technological advancements have substantially increased the potential usefulness of VR for pharmacy education by providing immersive educational activities that mimic real world experiences to reinforce didactic and laboratory concepts. Virtual reality training that uses head-mounted displays is just beginning in pharmacy education, but more educational VR programs are becoming available. Further research will be necessary to fully understand the potential impact of VR on pharmacy education. Summary. Virtual reality technology can provide an immersive and interactive learning environment, overcoming many of the early challenges faced by instructors who used virtual activities for pharmacy education. With further technological and software development, VR has the potential to become an integral part of pharmacy education.


Subject(s)
Education, Pharmacy/methods , Education, Pharmacy/trends , Virtual Reality , Humans , Models, Educational , Problem-Based Learning , Simulation Training/methods , Software
7.
Curr Pharm Teach Learn ; 10(10): 1384-1390, 2018 10.
Article in English | MEDLINE | ID: mdl-30527368

ABSTRACT

BACKGROUND AND PURPOSE: Online distance education has become popular in pharmacy education, but it can be challenging to provide engaging experiences such as team-based learning (TBL) in this format. This study explored the utility of virtual reality (VR) as a platform to provide the engaging elements of TBL, without students needing to be physically present in the same room. EDUCATIONAL ACTIVITY AND SETTING: Volunteers participated in a modified TBL exercise in VR, followed by a survey of the experience. The survey included Likert-type questions to evaluate the level of immersion and perceived engagement, comfort and desirability of VR-TBL experiences. FINDINGS AND DISCUSSION: The majority of the responses to the 14-question survey were 'agree' or 'strongly agree'. Ninety-four percent (94.4%) of participants strongly agreed that this was a fun experience, and 94.4% of participants strongly agreed that they would take a course in this format if it was offered. Although none of the questions received a majority of 'disagree' or 'strongly disagree' responses, areas for improvement included ease of use of the technology, comfort and improving the learning activity. SUMMARY: The response of participants to this study was positive and the overall conclusion was that VR has the potential to be a useful tool for online, distance TBL, and should be explored further.


Subject(s)
Education, Distance/standards , Problem-Based Learning/standards , Virtual Reality , Adult , Curriculum/standards , Education, Distance/methods , Education, Distance/trends , Education, Pharmacy/methods , Education, Pharmacy/standards , Education, Pharmacy/statistics & numerical data , Educational Measurement/methods , Educational Measurement/statistics & numerical data , Female , Humans , Male , Problem-Based Learning/methods , Problem-Based Learning/trends , Surveys and Questionnaires , Texas
8.
Curr Pharm Teach Learn ; 10(1): 90-95, 2018.
Article in English | MEDLINE | ID: mdl-29248081

ABSTRACT

BACKGROUND AND PURPOSE: The study investigates students' perceptions of the value of implementing a team exam to enhance learning prior to a summative assessment. Team exams are similar to midterm exams, except that answering questions is a team effort. EDUCATIONAL ACTIVITY AND SETTING: Data was collected from second year pharmacy students at California Northstate University College of Pharmacy (CNUCOP) through a self-administered online survey. The survey questions included closed-ended questions to evaluate students' perception on preparedness for a summative assessment and to rank advantages and disadvantages of the team exams. FINDINGS: Of the 40 students who completed the survey (38% response rate), 100% of participants agreed that having a team exam prior to a major exam made them feel more prepared for a major summative exam. Ninety-seven percent of students believed that the team exam helped them to identify gaps in their knowledge and 85% agreed that taking a team exam reinforced their knowledge by teaching other students. The survey results did not identify any major disadvantages to holding a team exam. SUMMARY: Students perceived that taking a team exam prior to a midterm exam is an effective approach to review the course contents and identify areas of improvement.


Subject(s)
Perception , Problem-Based Learning/standards , Students, Pharmacy/psychology , Test Taking Skills/psychology , Adult , California , Curriculum/standards , Female , Humans , Learning , Male , Problem-Based Learning/methods , Surveys and Questionnaires
9.
Inflammopharmacology ; 20(3): 159-67, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22231719

ABSTRACT

Non-steroidal anti-inflammatory drugs (NSAIDs) have been used extensively in the treatment of inflammatory disorders and pain. In recent years, emerging data suggest that some NSAIDs possess pharmacological properties, in addition to cyclooxygenase inhibition, which may be beneficial in the treatment of several neurological conditions. For example, fenamate NSAIDs potentiate GABA-A receptor function, indomethacin scavenges nitric oxide free radicals, and acetylsalicylic acid inhibits the translocation of NF-κB, all of which may contribute to their neuroprotective actions in selected experimental models of stroke. The purpose of this review is to explore the diverse pharmacological properties of NSAIDs in relation to their potential value in the treatment of selected neurological diseases.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Nervous System Diseases/drug therapy , Neuroprotective Agents/administration & dosage , Animals , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Humans , Nervous System Diseases/pathology , Nervous System Diseases/prevention & control , Neuroprotective Agents/chemistry , Treatment Outcome
10.
Neurochem Int ; 59(3): 404-12, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21315124

ABSTRACT

Human pluripotent stem cells have enormous potential value in neuropharmacology and drug discovery yet there is little data on the major classes and properties of receptors and ion channels expressed by neurons derived from these stem cells. Recent studies in this lab have therefore used conventional patch-clamp electrophysiology to investigate the pharmacological properties of the ligand and voltage-gated ion channels in neurons derived and maintained in vitro from the human stem cell (hSC) line, TERA2.cl.SP12. TERA2.cl.SP12 stem cells were differentiated with retinoic acid and used in electrophysiological experiments 28-50 days after beginning differentiation. HSC-derived neurons generated large whole cell currents with depolarizing voltage steps (-80 to 30 mV) comprised of an inward, rapidly inactivating component and a delayed, slowly deactivating outward component. The fast inward current was blocked by the sodium channel blocker tetrodotoxin (0.1 µM) and the outward currents were significantly reduced by tetraethylammonium ions (TEA, 5 mM) consistent with the presence of functional Na and K ion channels. Application of the inhibitory neurotransmitters, GABA (0.1-1000 µM) or glycine (0.1-1000 µM) evoked concentration dependent currents. The GABA currents were inhibited by the convulsants, picrotoxin (10 µM) and bicuculline (3 µM), potentiated by the NSAID mefenamic acid (10-100 µM), the general anaesthetic pentobarbital (100 µM), the neurosteroid allopregnanolone and the anxiolytics chlordiazepoxide (10 µM) and diazepam (10 µM) all consistent with the expression of GABA(A) receptors. Responses to glycine were reversibly blocked by strychnine (10 µM) consistent with glycine-gated chloride channels. The excitatory agonists, glutamate (1-1000 µM) and NMDA (1-1000 µM) activated concentration-dependent responses from hSC-derived neurons. Glutamate currents were inhibited by kynurenic acid (1 mM) and NMDA responses were blocked by MgCl(2) (2 mM) in a highly voltage-dependent manner. Together, these findings show that neurons derived from human stem cells develop an array of functional receptors and ion channels with a pharmacological profile in keeping with that described for native neurons. This study therefore provides support for the hypothesis that stem cells may provide a powerful source of human neurons for future neuropharmacological studies.


Subject(s)
Cell Differentiation , Neurons/drug effects , Stem Cells/cytology , Chlordiazepoxide/pharmacology , Diazepam/pharmacology , Glycine/pharmacology , Humans , Immunohistochemistry , Ion Channel Gating , Ligands , Mefenamic Acid/pharmacology , Neurons/cytology , Pentobarbital/pharmacology , Pregnanolone/pharmacology , Tetraethylammonium/pharmacology , Tetrodotoxin/pharmacology , gamma-Aminobutyric Acid/pharmacology , gamma-Aminobutyric Acid/physiology
11.
FEMS Yeast Res ; 7(8): 1218-29, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17662057

ABSTRACT

Expression of GEF1 in Xenopus laevis oocytes and HEK-293 cells gave rise to a Cl- channel that remained permanently open and was blocked by nitro-2-(3-phenyl-propylamino) benzoic acid and niflumic acid. NPPB induced petite-like colonies, resembling the GEF1 knock-out. The fluorescent halide indicator SPQ was quenched in a wild-type strain, in contrast to both a GEF1 knock-out strain and yeast grown in the presence of NPPB. Immunogold and electron microscopy located Gef1p in the plasma membrane, vacuole, endoplasmic reticulum and Golgi apparatus. Eleven substitutions in five residues forming the ion channel of GEF1 were introduced; some of them (S186A, I188N, Y459D, Y459F, Y459V, I467A, I467N and F468N) did not rescue the pet phenotype, whereas F468A, A558F and A558Y formed normal colonies. All the pet mutants showed reduced O2 consumption, small mitochondria and mostly disrupted organelles. Finally, electron microscopy revealed that the plasma membrane of the mutants develop multiple foldings and highly ordered cylindrical protein-membrane complexes. All the experiments above suggest that Gef1p transports Cl- through the plasma membrane and reveal the importance of critical amino acids for the proper function of the protein as suggested by structural models. However, the mechanism of activation of the channel has yet to be defined.


Subject(s)
Cell Membrane/chemistry , Chloride Channels/physiology , Chlorides/metabolism , Cloning, Molecular , Saccharomyces cerevisiae Proteins/physiology , Saccharomyces cerevisiae/physiology , Amino Acid Substitution/genetics , Animals , Cell Line , Cell Membrane/genetics , Chloride Channels/analysis , Chloride Channels/genetics , Endoplasmic Reticulum/chemistry , Enzyme Inhibitors/pharmacology , Gene Deletion , Gene Expression , Golgi Apparatus/chemistry , Humans , Microscopy, Electron, Transmission , Microscopy, Immunoelectron , Models, Molecular , Mutagenesis, Site-Directed , Niflumic Acid , Nitrobenzoates/pharmacology , Organelles/ultrastructure , Oxygen Consumption , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae Proteins/analysis , Saccharomyces cerevisiae Proteins/genetics , Vacuoles/chemistry , Xenopus laevis
12.
Neurochem Int ; 51(6-7): 440-6, 2007.
Article in English | MEDLINE | ID: mdl-17560686

ABSTRACT

Fenamate NSAIDs have several central effects, including anti-epileptic and neuroprotective actions. The underlying mechanism(s) of these actions are not presently understood. In this study, the effects of five members of the fenamate NSAID group were investigated on native ligand-gated ion channels expressed in cultured rat hippocampal neurons. All fenamates tested (1-100 microM) dose-dependently potentiated GABA-evoked currents; mefenamic acid (MFA) was the most potent and efficacious and was found to shift the GABA dose-response curve to the left without effect on the maximum amplitude or the GABA Hill Slope. The modulation of GABA receptors by MFA was not reduced in the presence of the benzodiazepine antagonist, flumazenil (10 microM) and was moderately voltage-dependent. MFA at concentrations >or=10 microM evoked dose-dependent currents in the absence of GABA. These currents were potentiated by diazepam (1 microM) and blocked by bicuculline (10 microM). The MFA (50 microM) current-voltage relationship and reversal potential were similar to that evoked by GABA. MFA (1-100 microM) had no effects on sub-maximal glycine, glutamate or NMDA evoked currents. These data show that fenamate NSAIDs are a highly effective class of GABA(A) receptor modulator and activators.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Fenamates/pharmacology , Hippocampus/drug effects , Neurons/drug effects , Receptors, GABA-A/drug effects , Synaptic Transmission/physiology , Animals , Cells, Cultured , Diazepam/pharmacology , Dose-Response Relationship, Drug , Flumazenil/pharmacology , GABA Antagonists/pharmacology , GABA Modulators/pharmacology , Hippocampus/metabolism , Membrane Potentials/drug effects , Membrane Potentials/physiology , Neural Inhibition/drug effects , Neural Inhibition/physiology , Neurons/metabolism , Patch-Clamp Techniques , Rats , Receptors, GABA-A/metabolism , Synaptic Transmission/drug effects , gamma-Aminobutyric Acid/metabolism
13.
Neuropharmacology ; 50(8): 1016-29, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16620882

ABSTRACT

Lacosamide (LCM) is anticonvulsant in animal models and is in phase 3 assessment for epilepsy and neuropathic pain. Here we seek to identify cellular actions for the new drug and effects on recognised target sites for anticonvulsant drugs. Radioligand binding and electrophysiology were used to study the effects of LCM at well-established mammalian targets for clinical anticonvulsants. 10 microM LCM did not bind with high affinity to a plethora of rodent, guinea pig or human receptor sites including: AMPA; Kainate; NMDA (glycine/PCP/MK801); GABA(A) (muscimol/benzodiazepine); GABA(B); adenosine A1,2,3; alpha1, alpha2; beta1, beta2; M1,2,3,4,5; H1,2,3; CB1,2; D1,2,3,4,5; 5HT1A,1B,2A,2C,3,5A,6,7 and KATP. Weak displacement (25%) was evident at batrachotoxin site 2 on voltage gated Na+ channels. LCM did not inhibit neurotransmitter transport mechanisms for norepinephrine, dopamine, 5-HT or GABA, nor did it inhibit GABA transaminase. LCM at 100 microM produced a significant reduction in the incidence of excitatory postsynaptic currents (EPSC's) and inhibitory postsynaptic currents (IPSC's) in cultured cortical cells and blocked spontaneous action potentials (EC50 61 microM). LCM did not alter resting membrane potential or passive membrane properties following application of voltage ramps between -70 to +20 mV. The voltage-gated sodium channel (VGSC) blocker phenytoin potently blocked sustained repetitive firing (SRF) but, in contrast, 100 microM LCM failed to block SRF. No effect was observed on voltage-clamped Ca2+ channels (T-, L-, N- or P-type). Delayed-rectifier or A-type potassium currents were not modulated by LCM (100 microM). LCM did not mimic the effects of diazepam as an allosteric modulator of GABA(A) receptor currents, nor did it significantly modulate evoked excitatory neurotransmission mediated by NMDA or AMPA receptors (n > or = 5). Evidently LCM perturbs excitability in primary cortical cultures but does not appear to do so via a high-affinity interaction with an acknowledged recognition site on a target for existing antiepileptic drugs.


Subject(s)
Acetamides/pharmacology , Anticonvulsants/pharmacology , Neurons/drug effects , Action Potentials/drug effects , Animals , Animals, Newborn , Brain/cytology , Calcium/metabolism , Cells, Cultured , Dose-Response Relationship, Drug , Drug Interactions , Embryo, Mammalian , Excitatory Amino Acid Agonists/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , In Vitro Techniques , Lacosamide , Neural Conduction/drug effects , Neural Inhibition/drug effects , Patch-Clamp Techniques/methods , Potassium/metabolism , Radioligand Assay/methods , Rats , Rats, Sprague-Dawley , Rats, Wistar , gamma-Aminobutyric Acid/pharmacology
14.
Neurochem Int ; 48(8): 703-7, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16487630

ABSTRACT

Neurosteroids are modulators of several receptors and ion channels and are implicated in the pathophysiology of several neuropsychiatric diseases including hepatic encephalopathy (HE). The neurosteroid, allopregnanolone, a positive allosteric modulator of GABA(A) receptors, accumulates in the brains of HE patients where it can potentiate GABA(A) receptor-mediated responses. Attenuation of the effects of neurosteroids on GABA-ergic neurotransmission is therefore of interest for the management of HE. In the present study, we determined the effect of the benzodiazepine partial inverse agonist, Ro15-4513, and the benzodiazepine antagonist, flumazenil on modulation of the GABA(A) mediated chloride currents by allopregnanolone and on spontaneous synaptic activity in cultured hippocampal neurons using the patch-clamp technique. Allopregnanolone (0.03-0.3 microM), dose-dependently potentiated GABA-induced currents, an action significantly reduced by Ro15-4513 (10 microM). In contrast, flumazenil (10 microM) had no effect on the ability of allopregnanolone to potentiate GABA(A) currents but it blocked the effects of Ro15-4513. The frequency of spontaneous synaptic activity was significantly reduced in the presence of allopregnanolone (0.1 microM) from 1.5+/-0.7 to 0.1+/-0.04Hz. This action was partially reversed by Ro15-4513 (10 microM) but was not significantly influenced by flumazenil (10 microM). These findings suggest that the beneficial affects of Ro15-4513 in experimental HE result from attenuation of the effects of neurosteroids at GABA(A) receptors. Our results may provide a rational basis for the use of benzodiazepine inverse agonists in the management and treatment of hepatic encephalopathy in patients with liver failure.


Subject(s)
Benzodiazepines/pharmacology , Hippocampus/metabolism , Neurons/metabolism , Pregnanolone/pharmacology , Receptors, GABA-A/drug effects , Affinity Labels/pharmacology , Allosteric Regulation/drug effects , Allosteric Regulation/physiology , Animals , Azides/pharmacology , Cells, Cultured , Chloride Channels/drug effects , Chloride Channels/metabolism , Dose-Response Relationship, Drug , Drug Interactions/physiology , Female , Flumazenil/pharmacology , GABA Modulators/pharmacology , Hepatic Encephalopathy/drug therapy , Hepatic Encephalopathy/metabolism , Hepatic Encephalopathy/physiopathology , Hippocampus/cytology , Hippocampus/drug effects , Male , Neural Inhibition/drug effects , Neural Inhibition/physiology , Neurons/drug effects , Patch-Clamp Techniques , Pregnanolone/metabolism , Rats , Rats, Wistar , Receptors, GABA-A/metabolism , Synaptic Transmission/drug effects , Synaptic Transmission/physiology
15.
Nat Med ; 10(1): 31-2, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14647497

ABSTRACT

Patients taking fluoroquinolone antibiotics such as norfloxacin exhibit a low incidence of convulsions and anxiety. These side effects probably result from antagonism of the neurotransmitter gamma-aminobutyric acid (GABA) at the brain GABA(A) receptor complex (GRC). Modification of norfloxacin yields molecules such as compound 4 that potentiate GABA action with alpha(2) subunit selectivity. Compound 4 is anxiolytic but does not cause sedation, and may represent a new class of ligands that have anxiolytic activity without sedative liability.


Subject(s)
Anti-Anxiety Agents/pharmacology , Anti-Infective Agents/pharmacology , Fluoroquinolones/pharmacology , Anti-Anxiety Agents/chemistry , Anti-Anxiety Agents/metabolism , Anti-Infective Agents/chemistry , Anti-Infective Agents/metabolism , Fluoroquinolones/chemistry , Fluoroquinolones/metabolism , Humans , Protein Binding , Receptors, GABA-A/metabolism , Recombinant Proteins/metabolism , gamma-Aminobutyric Acid/metabolism
16.
Environ Toxicol Pharmacol ; 15(2-3): 61-9, 2004 Jan.
Article in English | MEDLINE | ID: mdl-21782681

ABSTRACT

Resin acids from bleached wood pulp are toxic to fish. 12,14-Dichlorodehydroabietic acid (12,14-Cl(2)DHA) raises cytoplasmic Ca(2+) in synaptosomes and blocks neural GABA(A) receptors; however, the underlying mechanism remains unclear in these earlier rodent studies. 12,14-Cl(2)DHA (50µM) almost completely blocked native GABA(A) currents (rat cortical cultures) but had no significant effect on picrotoxin-sensitive recombinant human receptors in oocytes (α1, ß2 and γ2L: the most prevalent isoforms in mammalian brain). In oocytes, 12,14-Cl(2)DHA failed to produce a calcium-activated chloride current, in contrast to the calcium ionophore ionomycin (10µM). However, in cultured cortical pyramidal cells, both ionomycin and 12,14-Cl(2)DHA produced chloride-selective currents of similar magnitude (presumably secondary to Ca(2+) release). 12,14-Cl(2)DHA was unable to stimulate phosphate labelling of [(3)H ]-inositol in mouse synaptosomes, indicating that the study compound does not cause Ca(2+) release via an IP(3) mechanism. Calcium pump ATPase inhibition also seems unlikely since thapsigargin did not elevate free calcium in synaptosomes. 12,14-Cl(2)DHA clearly blocks GABA(A) currents indirectly: we infer that its toxicity may be secondary to the elevations in cytoplasmic Ca(2+) via an unidentified recognition site (or receptor) found in neuronal cells.

17.
Br J Pharmacol ; 135(8): 1977-87, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11959801

ABSTRACT

1. We examine the sensitivity of GABA(A) and glycine receptors (same ionotropic superfamily) to oleamide. We address subunit-dependence/modulatory mechanisms and analogies with depressant drugs. 2. Oleamide modulated human GABA(A) currents (alpha(1)beta(2)gamma(2L)) in oocytes (EC(50), 28.94+/-s.e.mean of 1.4 microM; Maximum 216%+/-35 of control, n=4). Modulation of human alpha1 glycine homo-oligomers (significant), was less marked, with a lower EC(50) (P<0.05) than GABA receptors (EC(50), 22.12+/-1.4 microM; Maximum 171%+/-30, n=11). 3. Only the hypnogenic cis geometric isomer enhanced glycine currents (without altering slope or maximal current, it reduced the glycine EC(50) from 322 to 239 microM: P<0.001). Modulation was not voltage-dependent or associated with a shift in E(r). 4. beta 1 containing GABA(A) receptors (insensitive to many depressant drugs) were positively modulated by oleamide. Oleamide efficacy was circa 2x greater at alpha(1)beta(1)gamma(2L) than alpha(1)beta(2)gamma(2L) (P=0.007). Splice variation in gamma subunits did not alter oleamide sensitivity. 5. cis-9,10-Octadecenoamide had no effect on the equilibrium binding of [(3)H]-muscimol or [(3)H]-EBOB to mouse brain membranes. It does not directly mimic GABA, or operate as a neurosteroid-, benzodiazepine- or barbiturate-like modulator of GABA(A)-receptors. 6. The transport of [(3)H]-GABA into mouse brain synaptoneurosomes was unaffected by high micromolar concentrations of cis-9,10-octadecenoamide. Oleamide does not enhance GABA-ergic currents or prolong IPSCs by inhibiting GABA transport. 7. Oleamide is a non-selective modulator of inhibitory ionotropic receptors. The sleep lipid exerts its effects indirectly, or at a novel recognition site on the GABA(A) complex.


Subject(s)
Brain/drug effects , Brain/physiology , Hypnotics and Sedatives/pharmacology , Oleic Acids/pharmacology , Receptors, GABA-A/physiology , Receptors, Glycine/physiology , Animals , Biological Transport, Active/drug effects , Bridged Bicyclo Compounds, Heterocyclic/metabolism , Chloride Channels/antagonists & inhibitors , Chloride Channels/physiology , Female , GABA-A Receptor Agonists , GABA-A Receptor Antagonists , Glycine/pharmacology , Glycine/physiology , Humans , Male , Mice , Muscimol/metabolism , Oocytes/drug effects , Oocytes/metabolism , Radioligand Assay , Receptors, Glycine/agonists , Receptors, Glycine/antagonists & inhibitors , Sleep/physiology , Synaptic Membranes/drug effects , Synaptic Membranes/metabolism , Tritium , Xenopus laevis , gamma-Aminobutyric Acid/metabolism , gamma-Aminobutyric Acid/pharmacology , gamma-Aminobutyric Acid/physiology
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