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2.
Br J Pharmacol ; 181(3): 375-392, 2024 02.
Article in English | MEDLINE | ID: mdl-37605852

ABSTRACT

BACKGROUND AND PURPOSE: Development of core concepts in disciplines such as biochemistry, microbiology and physiology have transformed teaching. They provide the foundation for the development of teaching resources for global educators, as well as valid and reliable approaches to assessment. An international research consensus recently identified 25 core concepts of pharmacology. The current study aimed to define and unpack these concepts. EXPERIMENTAL APPROACH: A two-phase, iterative approach, involving 60 international pharmacology education experts, was used. The first phase involved drafting definitions for core concepts and identifying key sub-concepts via a series of online meetings and asynchronous work. These were refined in the second phase, through a 2-day hybrid workshop followed by a further series of online meetings and asynchronous work. KEY RESULTS: The project produced consensus definitions for a final list of 24 core concepts and 103 sub-concepts of pharmacology. The iterative, discursive methodology resulted in modification of concepts from the original study, including change of 'drug-receptor interaction' to 'drug-target interaction' and the change of the core concept 'agonists and antagonists' to sub-concepts of drug-target interaction. CONCLUSIONS AND IMPLICATIONS: Definitions and sub-concepts of 24 core concepts provide an evidence-based foundation for pharmacology curricula development and evaluation. The next steps for this project include the development of a concept inventory to assess acquisition of concepts, as well as the development of case studies and educational resources to support teaching by the global pharmacology community, and student learning of the most critical and fundamental concepts of the discipline.


Subject(s)
Curriculum , Pharmacology , Humans
3.
Br J Clin Pharmacol ; 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38093035

ABSTRACT

Over recent years, studies have shown that science and health profession graduates demonstrate gaps in their fundamental pharmacology knowledge and ability to apply pharmacology concepts in practice. This article reviews the current challenges faced by pharmacology educators, including the exponential growth in discipline knowledge and competition for curricular time. We then argue that pharmacology education should focus on essential concepts that enable students to develop beyond 'know' towards 'know how to'. A concept-based approach will help educators prioritize and benchmark their pharmacology curriculum, facilitate integration of pharmacology with other disciplines in the curriculum, create alignment between universities and improve application of pharmacology knowledge to professional contexts such as safe prescribing practices. To achieve this, core concepts first need to be identified and unpacked, and methods for teaching and assessment using concept inventories developed. The International Society for Basic and Clinical Pharmacology Education Section (IUPHAR-Ed) Core Concepts of Pharmacology (CCP) initiative involves over 300 educators from the global pharmacology community. CCP has identified and defined the core concepts of pharmacology, together with key underpinning sub-concepts. To realize these benefits, pharmacology educators must develop methods to teach and assess core concepts. Work to develop concept inventories is ongoing, including identifying student misconceptions of the core concepts and creating a bank of multiple-choice questions to assess student understanding. Future work aims to develop and validate materials and methods to help educators embed core concepts within curricula. Potential strategies that educators can use to overcome factors that inhibit adoption of core concepts are presented.

5.
BMJ Open ; 13(10): e072808, 2023 10 05.
Article in English | MEDLINE | ID: mdl-37798022

ABSTRACT

OBJECTIVES: In an increasingly global society, there is a need to develop culturally competent doctors who can work effectively across diverse populations. International learning opportunities in undergraduate healthcare programmes show various benefits. In medical education, these occur predominantly towards the end of degree programmes as electives, with scant examples of programmes for preclinical students. This study set out to identify the multicultural learning experiences following an early year international medical student exchange programme between the UK and Malaysian campuses of one UK medical school. SETTING: Two cohorts of international exchange programme for second year medical students in the UK and Malaysia. DESIGN: Interpretivist qualitative design using semistructured interviews/focus groups with students and faculty. METHODS: Participants were asked about their learning experiences during and after the exchange. Data were recorded with consent and transcribed verbatim. Thematic analysis was used to analyse the data. RESULTS: Four themes were identified: (1) overall benefits of the exchange programme, (2) personal growth and development, (3) understanding and observing a different educational environment and (4) experiencing different healthcare systems. CONCLUSION: The international exchange programme highlighted differences in learning approaches, students from both campuses gained valuable learning experiences which increased their personal growth, confidence, cultural competence, giving them an appreciation of a better work-life balance and effective time management skills. It is often a challenge to prepare healthcare professionals for work in a global multicultural workplace and we would suggest that exchange programmes early on in a medical curriculum would go some way to addressing this challenge.


Subject(s)
Students, Medical , Humans , Malaysia , Qualitative Research , Focus Groups , United Kingdom
6.
Br J Pharmacol ; 180(9): 1197-1209, 2023 05.
Article in English | MEDLINE | ID: mdl-36470846

ABSTRACT

BACKGROUND AND PURPOSE: In recent decades, a focus on the most critical and fundamental concepts has proven highly advantageous to students and educators in many science disciplines. Pharmacology, unlike microbiology, biochemistry, or physiology, lacks a consensus list of such core concepts. EXPERIMENTAL APPROACH: We sought to develop a research-based, globally relevant list of core concepts that all students completing a foundational pharmacology course should master. This two-part project consisted of exploratory and refinement phases. The exploratory phase involved empirical data mining of the introductory sections of five key textbooks, in parallel with an online survey of over 200 pharmacology educators from 17 countries across six continents. The refinement phase involved three Delphi rounds involving 24 experts from 15 countries across six continents. KEY RESULTS: The exploratory phase resulted in a consolidated list of 74 candidate core concepts. In the refinement phase, the expert group produced a consensus list of 25 core concepts of pharmacology. CONCLUSION AND IMPLICATIONS: This list will allow pharmacology educators everywhere to focus their efforts on the conceptual knowledge perceived to matter most by experts within the discipline. Next steps for this project include defining and unpacking each core concept and developing resources to help pharmacology educators globally teach and assess these concepts within their educational contexts.

7.
Med Sci Educ ; 31(6): 2177-2188, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34950534

ABSTRACT

Newcastle University UK operates an international campus, NUMed, in Malaysia. NUMed delivers the same medical degree programme as in the UK, within a different cultural context. In this paper, medical education faculty and NUMed graduates with experience working in both the UK and Malaysia provide insights into cross-cultural diversity in approaches to learning. Observations from small and large group teaching and approaches to assessment are discussed in relation to students' cultural backgrounds including previous learning experiences and English language abilities. We provide practice points for educators preparing a diverse range of students to work in global healthcare settings.

8.
Pharmacol Res Perspect ; 9(4): e00832, 2021 08.
Article in English | MEDLINE | ID: mdl-34346189

ABSTRACT

The British Pharmacological Society (BPS) developed a new core curriculum for undergraduate pharmacology degrees. To do this, a modification of the Delphi Process was used. Initially, a pharmacology educator workshop was hosted to explore the core attributes expected of pharmacology graduates. We then developed these discussions into knowledge, skills, and attitudes statements and sent them, in the form of a questionnaire, to our Expert Group, which included pharmacology professionals from across academia and industry. In an iterative process, the Expert Group were asked to rank each statement according to how much they agreed it was a core graduate attribute. Where there was disagreement, statements were modified according to feedback. After three rounds of questionnaires, we had a draft core curriculum which was then finalized through a discussion workshop with the education community. In this workshop, practical aspects of curriculum implementation were discussed and the potential for the Society to develop resources to support it considered. The revised core curriculum is freely available on the Society website: https://www.bps.ac.uk/media-library-assets/library/undergraduate-pharmacology-core-curriculum. Several examples exist of the curriculum making an impact within and beyond the United Kingdom, where it has been utilized in a quality assurance context, as a tool for curriculum review and also to guide building new programs. Through a series of further expert workshops, the BPS Education and Training committee is currently developing more granular learning outcomes to accompany the core curriculum alongside recommended resources to enable delivery. In addition, this expanded curriculum is also being reviewed and updated to ensure it is fully inclusive and represents the diversity of pharmacology educators and learners worldwide.


Subject(s)
Curriculum , Pharmacology/education , Delphi Technique , Societies, Scientific , United Kingdom
9.
Pharmacol Res Perspect ; 9(4): e00833, 2021 08.
Article in English | MEDLINE | ID: mdl-34309243

ABSTRACT

Multiple choice questions (MCQs) are a common form of assessment in medical schools and students seek opportunities to engage with formative assessment that reflects their summative exams. Formative assessment with feedback and active learning strategies improve student learning outcomes, but a challenge for educators, particularly those with large class sizes, is how to provide students with such opportunities without overburdening faculty. To address this, we enrolled medical students in the online learning platform PeerWise, which enables students to author and answer MCQs, rate the quality of other students' contributions as well as discuss content. A quasi-experimental mixed methods research design was used to explore PeerWise use and its impact on the learning experience and exam results of fourth year medical students who were studying courses in clinical sciences and pharmacology. Most students chose to engage with PeerWise following its introduction as a noncompulsory learning opportunity. While students perceived benefits in authoring and peer discussion, students engaged most highly with answering questions, noting that this helped them identify gaps in knowledge, test their learning and improve exam technique. Detailed analysis of the 2015 cohort (n = 444) with hierarchical regression models revealed a significant positive predictive relationship between answering PeerWise questions and exam results, even after controlling for previous academic performance, which was further confirmed with a follow-up multi-year analysis (2015-2018, n = 1693). These 4 years of quantitative data corroborated students' belief in the benefit of answering peer-authored questions for learning.


Subject(s)
Education, Medical, Undergraduate/methods , Educational Measurement/methods , Education, Distance , Humans , Peer Group , Students, Medical , Surveys and Questionnaires
10.
Commun Biol ; 4(1): 761, 2021 06 18.
Article in English | MEDLINE | ID: mdl-34145388

ABSTRACT

Regular exercise is important for physical and mental health. An underexplored and intriguing property of exercise is its actions on the body's 24 h or circadian rhythms. Molecular clock cells in the brain's suprachiasmatic nuclei (SCN) use electrical and chemical signals to orchestrate their activity and convey time of day information to the rest of the brain and body. To date, the long-lasting effects of regular physical exercise on SCN clock cell coordination and communication remain unresolved. Utilizing mouse models in which SCN intercellular neuropeptide signaling is impaired as well as those with intact SCN neurochemical signaling, we examined how daily scheduled voluntary exercise (SVE) influenced behavioral rhythms and SCN molecular and neuronal activities. We show that in mice with disrupted neuropeptide signaling, SVE promotes SCN clock cell synchrony and robust 24 h rhythms in behavior. Interestingly, in both intact and neuropeptide signaling deficient animals, SVE reduces SCN neural activity and alters GABAergic signaling. These findings illustrate the potential utility of regular exercise as a long-lasting and effective non-invasive intervention in the elderly or mentally ill where circadian rhythms can be blunted and poorly aligned to the external world.


Subject(s)
Circadian Clocks/physiology , Circadian Rhythm/physiology , Physical Conditioning, Animal/physiology , Animals , Behavior, Animal/physiology , GABAergic Neurons/metabolism , Male , Mice , Mice, Inbred C57BL , Models, Animal , Neuropeptides/metabolism , Signal Transduction/physiology , Suprachiasmatic Nucleus/physiology , Time Factors
11.
BMC Med Educ ; 20(1): 360, 2020 Oct 13.
Article in English | MEDLINE | ID: mdl-33050898

ABSTRACT

BACKGROUND: Arguably, Medical School curricula are deficient in learning opportunities related to the safe and effective use of medicines, in particular antimicrobials. Infection management is complex and multidisciplinary, and learning opportunities should reflect these principles. Aligned to the complexity of the subject matter, simulation and interprofessional based teaching are methods that can foster the collaborative skills required of future healthcare professionals. There have been calls to develop these methods in the teaching of safe prescribing and the management of infections; however, reports of such studies are limited. METHODS: We developed an interprofessional education (IPE) conference for second year undergraduate medical and pharmacy students based in the North East of England. We considered contact theory in the design of three small group interprofessional workshops, on the broad themes of antimicrobial stewardship, infection management and patient safety. A mixed methods approach assessed students' attitudes towards IPE, barriers and facilitators of learning, and perceived learning gains. Qualitative data from workshop evaluation forms were analysed thematically, while quantitative data were analysed descriptively and differences between medical and pharmacy cohorts analysed using unpaired two-tailed t-tests. RESULTS: 226/352 students returned the workshop evaluation forms (66% of pharmacy students, 62% of medical students). 281/352 students responded to a series of Likert scale questions on the value of interprofessional education (88% of pharmacy students, 70% of medical students). Students reported acquisition of knowledge and skills, including concepts and procedures related to infection management and antimicrobial prescribing, and the development of problem-solving and critical evaluation skills. Students reflected on their attitude towards interprofessional collaboration. They reported a greater understanding of the roles of other healthcare professionals, reflected on the importance of effective communication in ensuring patient safety, and were more confident to work in interprofessional teams after the conference. CONCLUSIONS: A robust IPE event, theoretically underpinned by contact theory and developed collaboratively, achieved interprofessional learning at scale and helped develop healthcare professionals willing to collaborate across disciplines. The resources, and evaluation insights based on the 3P (presage, process, and product) model of learning and teaching, will be of value to other educators who seek to develop theoretically-sound IPE interventions.


Subject(s)
Anti-Infective Agents , Interprofessional Education , Anti-Infective Agents/therapeutic use , Attitude of Health Personnel , Curriculum , England , Humans , Interprofessional Relations
12.
J Interprof Care ; 32(5): 653-655, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30044675

ABSTRACT

An interprofessional education conference was developed and delivered to undergraduate medical and pharmacy students to address training needs around appropriate antimicrobial prescribing, identification and management of sepsis, patient safety and interprofessional working. The day consisted of keynote lectures delivered by specialist speakers and three small group interprofessional teaching sessions exploring (1) the choice and prescribing of antimicrobials for a range of infections, (2) the diagnosis and management of sepsis utilising simulation methodology and (3) the discussion of a clinical error using significant event analysis. Students' attitudes and acceptance towards this educational intervention were assessed using a mixed methods evaluation. The delivery of an effective learning and teaching intervention in a conference format to a large cohort of pharmacy and medical students (n = 352) was found to be feasible. The logistics of organising an IPE conference of this scale were challenging but not insurmountable if sufficient staff and financial resources can be secured. Scheduling access to adequate teaching rooms and student timetabling were amongst the other important aspects affecting the success of such an event.


Subject(s)
Competency-Based Education/methods , Congresses as Topic , Cooperative Behavior , Interprofessional Relations , Students, Health Occupations/statistics & numerical data , Education, Medical, Undergraduate , Humans
14.
J Physiol ; 591(4): 1063-80, 2013 Feb 15.
Article in English | MEDLINE | ID: mdl-23207594

ABSTRACT

Within the core molecular clock, protein phosphorylation and degradation play a vital role in determining circadian period. The 'after-hours' (Afh) mutation in mouse slows the degradation of the core clock protein Cryptochrome, lengthening the period of the molecular clock in the suprachiasmatic nuclei (SCN) and behavioural wheel-running rhythms. However, we do not yet know how the Afh mutation affects other aspects of physiology or the activity of circadian oscillators in other brain regions. Here we report that daily rhythms of metabolism and ingestive behaviours are altered in these animals, as are PERIOD2::LUCIFERASE (PER2::LUC) rhythms in mediobasal hypothalamic nuclei, which influence these behaviours. Overall there is a trend towards period lengthening and a decrease in amplitude of PER2::LUC rhythms throughout the brain. Imaging of single cells from the arcuate and dorsomedial hypothalamic nuclei revealed this reduction in tissue oscillator amplitude to be due to a decrease in the amplitude, rather than a desynchrony, of single cells. Consistent with existing models of oscillator function, this cellular phenotype was associated with a greater susceptibility to phase-shifting stimuli in vivo and in vitro, with light evoking high-amplitude Type 0 resetting in Afh mutant mice. Together, these findings reveal unexpected consequences of the Afh mutation on the amplitude and synchrony of individual cellular oscillators in the SCN.


Subject(s)
Circadian Rhythm Signaling Peptides and Proteins/physiology , Circadian Rhythm/physiology , Animals , Behavior, Animal/physiology , Circadian Clocks/physiology , Drinking Behavior/physiology , Energy Metabolism , Mice , Mice, Mutant Strains , Mutation , Running/physiology , Suprachiasmatic Nucleus/physiology
15.
Essays Biochem ; 49(1): 1-17, 2011 Jun 30.
Article in English | MEDLINE | ID: mdl-21819381

ABSTRACT

Humans and other mammals exhibit a remarkable array of cyclical changes in physiology and behaviour. These are often synchronized to the changing environmental light-dark cycle and persist in constant conditions. Such circadian rhythms are controlled by an endogenous clock, located in the suprachiasmatic nuclei of the hypothalamus. This structure and its cells have unique properties, and some of these are reviewed to highlight how this central clock controls and sculpts our daily activities.


Subject(s)
Behavior/physiology , Biological Clocks/physiology , Circadian Rhythm/physiology , Neurons/physiology , Suprachiasmatic Nucleus/physiology , Action Potentials/physiology , Animals , Humans , Hypothalamus/metabolism , Hypothalamus/physiology , Neurons/metabolism , Photoperiod , Suprachiasmatic Nucleus/metabolism
16.
PLoS One ; 6(4): e18926, 2011 Apr 29.
Article in English | MEDLINE | ID: mdl-21559484

ABSTRACT

Circadian rhythms in physiology and behavior are coordinated by the brain's dominant circadian pacemaker located in the suprachiasmatic nuclei (SCN) of the hypothalamus. Vasoactive intestinal polypeptide (VIP) and its receptor, VPAC(2), play important roles in the functioning of the SCN pacemaker. Mice lacking VPAC(2) receptors (Vipr2(-/-)) express disrupted behavioral and metabolic rhythms and show altered SCN neuronal activity and clock gene expression. Within the brain, the SCN is not the only site containing endogenous circadian oscillators, nor is it the only site of VPAC(2) receptor expression; both VPAC(2) receptors and rhythmic clock gene/protein expression have been noted in the arcuate (Arc) and dorsomedial (DMH) nuclei of the mediobasal hypothalamus, and in the pituitary gland. The functional role of VPAC(2) receptors in rhythm generation and maintenance in these tissues is, however, unknown. We used wild type (WT) and Vipr2(-/-) mice expressing a luciferase reporter (PER2::LUC) to investigate whether circadian rhythms in the clock gene protein PER2 in these extra-SCN tissues were compromised by the absence of the VPAC(2) receptor. Vipr2(-/-) SCN cultures expressed significantly lower amplitude PER2::LUC oscillations than WT SCN. Surprisingly, in Vipr2(-/-) Arc/ME/PT complex (Arc, median eminence and pars tuberalis), DMH and pituitary, the period, amplitude and rate of damping of rhythms were not significantly different to WT. Intriguingly, while we found WT SCN and Arc/ME/PT tissues to maintain a consistent circadian phase when cultured, the phase of corresponding Vipr2(-/-) cultures was reset by cull/culture procedure. These data demonstrate that while the main rhythm parameters of extra-SCN circadian oscillations are maintained in Vipr2(-/-) mice, the ability of these oscillators to resist phase shifts is compromised. These deficiencies may contribute towards the aberrant behavior and metabolism associated with Vipr2(-/-) animals. Further, our data indicate a link between circadian rhythm strength and the ability of tissues to resist circadian phase resetting.


Subject(s)
Neuropeptides/chemistry , Oscillometry/methods , Receptors, Vasoactive Intestinal Peptide, Type II/genetics , Suprachiasmatic Nucleus/metabolism , Animals , Circadian Rhythm , Colforsin/metabolism , Crosses, Genetic , Gastrin-Releasing Peptide/chemistry , Hypothalamus/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Period Circadian Proteins/genetics , Pituitary Gland/metabolism , Signal Transduction
17.
J Neurosci ; 30(9): 3508-17, 2010 Mar 03.
Article in English | MEDLINE | ID: mdl-20203211

ABSTRACT

Actin-rich dendritic spines are the locus of excitatory synaptic transmission and plastic events such as long-term potentiation (LTP). Morphological plasticity of spines accompanies activity-dependent changes in synaptic strength. Several Rho GTPase family members are implicated in regulating neuronal and, in particular, spine structure via actin and the actin-binding protein cofilin. However, despite expression in hippocampus and cortex, its ability to modulate actin-regulatory proteins, and its induction during aging, RhoB has been relatively neglected. We previously demonstrated that LTP is associated with specific RhoB activation. Here, we further examined its role in synaptic function using mice with genetic deletion of the RhoB GTPase (RhoB(-/-) mice). Normal basal synaptic transmission accompanied reduced paired-pulse facilitation and post-tetanic potentiation in the hippocampus of RhoB(-/-) mice. Early phase LTP was significantly reduced in RhoB(-/-) animals, whereas the later phase was unaffected. In wild-type mice (RhoB(+/+)), Western blot analysis of potentiated hippocampus showed significant increases in phosphorylated cofilin relative to nonpotentiated slices, which were dramatically impaired in RhoB(-/-) slices. There was also a deficit in phosphorylated Lim kinase levels in the hippocampus from RhoB(-/-) mice. Morphological analysis suggested that lack of RhoB resulted in increased dendritic branching and decreased spine number. Furthermore, an increase in the proportion of stubby relative to thin spines was observed. Moreover, spines demonstrated increased length along with increased head and neck widths. These data implicate RhoB in cofilin regulation and dendritic and spine morphology, highlighting its importance in synaptic plasticity at a structural and functional level.


Subject(s)
Dendritic Spines/metabolism , Hippocampus/metabolism , Neuronal Plasticity/genetics , Pyramidal Cells/metabolism , Synapses/metabolism , rhoB GTP-Binding Protein/genetics , Animals , Cell Shape/genetics , Cofilin 1/metabolism , Dendritic Spines/ultrastructure , Hippocampus/cytology , Lim Kinases/metabolism , Long-Term Potentiation/genetics , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Organ Culture Techniques , Patch-Clamp Techniques , Phosphorylation/drug effects , Pyramidal Cells/cytology , Rats , Synapses/ultrastructure , Synaptic Transmission/genetics
18.
Mol Brain ; 2: 28, 2009 Aug 27.
Article in English | MEDLINE | ID: mdl-19712475

ABSTRACT

BACKGROUND: In mammals, the synchronized activity of cell autonomous clocks in the suprachiasmatic nuclei (SCN) enables this structure to function as the master circadian clock, coordinating daily rhythms in physiology and behavior. However, the dominance of this clock has been challenged by the observations that metabolic duress can over-ride SCN controlled rhythms, and that clock genes are expressed in many brain areas, including those implicated in the regulation of appetite and feeding. The recent development of mice in which clock gene/protein activity is reported by bioluminescent constructs (luciferase or luc) now enables us to track molecular oscillations in numerous tissues ex vivo. Consequently we determined both clock activities and responsiveness to metabolic perturbations of cells and tissues within the mediobasal hypothalamus (MBH), a site pivotal for optimal internal homeostatic regulation. RESULTS: Here we demonstrate endogenous circadian rhythms of PER2::LUC expression in discrete subdivisions of the arcuate (Arc) and dorsomedial nuclei (DMH). Rhythms resolved to single cells did not maintain long-term synchrony with one-another, leading to a damping of oscillations at both cell and tissue levels. Complementary electrophysiology recordings revealed rhythms in neuronal activity in the Arc and DMH. Further, PER2::LUC rhythms were detected in the ependymal layer of the third ventricle and in the median eminence/pars tuberalis (ME/PT). A high-fat diet had no effect on the molecular oscillations in the MBH, whereas food deprivation resulted in an altered phase in the ME/PT. CONCLUSION: Our results provide the first single cell resolution of endogenous circadian rhythms in clock gene expression in any intact tissue outside the SCN, reveal the cellular basis for tissue level damping in extra-SCN oscillators and demonstrate that an oscillator in the ME/PT is responsive to changes in metabolism.


Subject(s)
Biological Clocks/physiology , Circadian Rhythm/physiology , Hypothalamus/physiology , Neuroglia/metabolism , Neurons/metabolism , Action Potentials/drug effects , Animals , Arcuate Nucleus of Hypothalamus/drug effects , Arcuate Nucleus of Hypothalamus/physiology , Biological Clocks/drug effects , Circadian Rhythm/drug effects , Colforsin/pharmacology , Dietary Fats/administration & dosage , Dietary Fats/pharmacology , Feeding Behavior/drug effects , Food Deprivation , Hypothalamus/drug effects , Luciferases/metabolism , Luminescent Measurements , Male , Median Eminence/drug effects , Median Eminence/physiology , Mice , Neuroglia/drug effects , Neurons/drug effects , Organ Specificity/drug effects , Period Circadian Proteins/metabolism , Sodium Channels/metabolism , Suprachiasmatic Nucleus/drug effects , Suprachiasmatic Nucleus/physiology , Tetrodotoxin/pharmacology
19.
J Neurochem ; 106(4): 1646-57, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18554318

ABSTRACT

Vasoactive intestinal polypeptide and its receptor, VPAC(2), play important roles in the functioning of the brain's circadian clock in the suprachiasmatic nuclei (SCN). Mice lacking VPAC(2) receptors (Vipr2(-/-)) show altered circadian rhythms in locomotor behavior, neuronal firing rate, and clock gene expression, however, the nature of molecular oscillations in individual cells is unclear. Here, we used real-time confocal imaging of a destabilized green fluorescent protein (GFP) reporter to track the expression of the core clock gene Per1 in live SCN-containing brain slices from wild-type (WT) and Vipr2(-/-) mice. Rhythms in Per1-driven GFP were detected in WT and Vipr2(-/-) cells, though a significantly lower number and proportion of cells in Vipr2(-/-) slices expressed detectable rhythms. Further, Vipr2(-/-) cells expressed significantly lower amplitude oscillations than WT cells. Within each slice, the phases of WT cells were synchronized whereas cells in Vipr2(-/-) slices were poorly synchronized. Most GFP-expressing cells, from both genotypes, expressed neither vasopressin nor vasoactive intestinal polypeptide. Pharmacological blockade of VPAC(2) receptors in WT SCN slices partially mimicked the Vipr2(-/-) phenotype. These data demonstrate that intercellular communication via the VPAC(2) receptor is important for SCN neurons to sustain robust, synchronous oscillations in clock gene expression.


Subject(s)
Eye Proteins/biosynthesis , Gene Expression Regulation/physiology , Receptors, Vasoactive Intestinal Peptide, Type II/biosynthesis , Suprachiasmatic Nucleus/metabolism , Animals , Cells, Cultured , Eye Proteins/analysis , Eye Proteins/genetics , Female , Male , Mice , Mice, Knockout , Mice, Transgenic , Microscopy, Confocal/methods , Motor Activity/physiology , Period Circadian Proteins , Receptors, Vasoactive Intestinal Peptide, Type II/analysis , Receptors, Vasoactive Intestinal Peptide, Type II/deficiency , Receptors, Vasoactive Intestinal Peptide, Type II/genetics , Receptors, Vasoactive Intestinal Peptide, Type II/physiology , Suprachiasmatic Nucleus/chemistry
20.
Eur J Neurosci ; 25(11): 3195-216, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17552989

ABSTRACT

The suprachiasmatic nucleus of the hypothalamus (SCN) is the master circadian pacemaker or clock in the mammalian brain. Canonical theory holds that the output from this single, dominant clock is responsible for driving most daily rhythms in physiology and behaviour. However, important recent findings challenge this uniclock model and reveal clock-like activities in many neural and non-neural tissues. Thus, in addition to the SCN, a number of areas of the mammalian brain including the olfactory bulb, amygdala, lateral habenula and a variety of nuclei in the hypothalamus, express circadian rhythms in core clock gene expression, hormone output and electrical activity. This review examines the evidence for extra-SCN circadian oscillators in the mammalian brain and highlights some of the essential properties and key differences between brain oscillators. The demonstration of neural pacemakers outside the SCN has wide-ranging implications for models of the circadian system at a whole-organism level.


Subject(s)
Biological Clocks/physiology , Brain/anatomy & histology , Brain/physiology , Circadian Rhythm/physiology , Animals , Humans , Mammals/anatomy & histology , Mammals/physiology , Models, Biological , Periodicity
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