Abstract:
:We present comparative experimental evidence for the induction of synaptic potentiation and depression in organotypic cultures of hippocampus and in visual cortex in vitro and in vivo. The effects of associative pairings on the efficacy of synaptic transmission are analyzed as a function of the temporal delay between presynaptic activity and post-synaptic changes imposed in membrane potential. Synchronous association at a low temporal frequency (< 0.5 Hz) between presynaptic input and postsynaptic depolarization resulted in homosynaptic potentiation of functionally identified postsynaptic potentials in the three types of preparation. Synchronous pairing of afferent activity with hyperpolarization of the postsynaptic cell resulted in homosynaptic depression in visual cortex in vivo and in vitro. An associative form of depression was induced in hippocampus when the test input was followed repeatedly with a fixed-delay postsynaptic depolarization imposed either by intracellular current injection or synaptically. The latter process might play a significant role in heterosynaptic plasticity in visual cortex in vivo and in vitro, if it is assumed that associative depression still operates in visual cortex a few seconds after the initial surge of calcium in the postsynaptic cell. We conclude that the precise timing between presynaptic activity and polarization changes in postsynaptic membrane potential up- and down-regulates the efficacy of active pathways.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Debanne D,Shulz DE,Frégnac Ydoi
10.1139/y95-185subject
Has Abstractpub_date
1995-09-01 00:00:00pages
1295-311issue
9eissn
0008-4212issn
1205-7541journal_volume
73pub_type
杂志文章abstract::The pharmacological characteristics of postjunctional alpha-adrenoceptors in isolated canine internal carotid arteries were investigated by the use of selective agonists and antagonists for alpha 1- and alpha 2-adrenoceptors. Norepinephrine, phenylephrine, and xylazine caused concentration-dependent contractions in th...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y88-102
更新日期:1988-05-01 00:00:00
abstract::Hyperglycemia in diabetes induces increased endothelin-1 (ET-1) production in the retina, kidney, and heart that may lead to hemodynamic impairment, permeability alteration, and increased extracellular matrix (ECM) protein production. Chronically elevated blood glucose levels may cause oxidative stress in these target...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/Y08-033
更新日期:2008-06-01 00:00:00
abstract::The present experiments were designed to evaluate vascular reactivity to angiotensin II in rats with experimental cirrhosis of the liver (induced with CCl4 and phenobarbital) before ascites appearance. The systemic pressor response to angiotensin II in conscious animals and the contractile effect of angiotensin II in ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y89-243
更新日期:1989-12-01 00:00:00
abstract::Electrophysiological studies were performed on in vitro slice preparations of sympathetic ganglia excised from peripherally perfused, brain-dead human donors. The intracellular recordings in 16 neurons showed resting potentials and input resistances mostly in the ranges reported for sympathetic neurons in other mammal...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y88-138
更新日期:1988-06-01 00:00:00
abstract::Physical exercise is essential for the amelioration of insulin resistance. The mechanisms in charge of improved insulin resistance, regulated by exercise, are insufficient inquired. Previous researches revealed that SIRT6-mediated insulin signaling acts a crucial character in hepatic IR. The objective of our research ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2020-0083
更新日期:2020-09-24 00:00:00
abstract::This report reviews the research and mentoring career of Richard B. Stein (1940-). In 1962, he completed a B.S. degree in physics at the Massachusetts Institute of Technology, USA, and thereafter an M.A. (1964), Ph.D. (1966), and postdoctoral training (1966-68) at the University of Oxford, UK. He subsequently assumed ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 传,历史文章,杂志文章
doi:10.1139/y04-063
更新日期:2004-08-01 00:00:00
abstract::The effects of atorvastatin and carboxymethylated β-glucan (CMG) on the lipoprotein-cholesterol (LP-C) and lipoprotein-triglyceride (LP-TG) fractions and subfractions at the early stage of murine hyperlipidemia, and its pleiotropic anti-inflammatory effects, were studied. Atorvastatin and CMG were administered in ICR ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y11-118
更新日期:2012-02-01 00:00:00
abstract::Our objective was to determine if the ability of an angiotensin-converting enzyme (ACE) inhibitor to attenuate neointima formation in balloon-damaged vessel is expressed in an isolated organ culture model of neointimal growth. In vivo balloon angioplasty in combination with in vitro organ culture was used to produce a...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:
更新日期:1999-10-01 00:00:00
abstract::Depletion of divalent cations before fractionation of the longitudinal muscle of the guinea pig ileum yielded a sarcolemma-enriched microsomal fraction free of mitochondria. A major portion of the ATPase activity in the presence of Mg, Na, and K was due to stimulation by Na alone. A further small stimulation by K was ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y77-162
更新日期:1977-10-01 00:00:00
abstract::We compared the determinants of spontaneous activity in explanted neonatal (2-day-old) rat ventricle cells and in reaggregates derived from 15-day-old chick embryos. We studied the beating rate with an optical recording method and the underlying electrical activity with glass microelectrodes using the K current blocke...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y89-126
更新日期:1989-07-01 00:00:00
abstract::Structural analysis of G-protein-coupled receptors has largely been limited to photoaffinity labeling and site-directed mutagenesis. This is primarily due to the difficulty in the production of antibodies against this class of receptors. We were therefore interested in tagging the amino-terminal side of the human angi...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:
更新日期:1997-06-01 00:00:00
abstract::Heparin was introduced into the stomach or duodenum of mice separately in doses of ca. 250 mg/kg. A slight anticoagulant effect in the systemic circulation was detected in whole blood clotting times and factor X inhibition. In contrast to most drugs, more heparin was absorbed from the stomach than from the intestine. ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y76-084
更新日期:1976-08-01 00:00:00
abstract::Physical activity promotes metabolic adaptations that improve body functionality and contribute to the prevention of some diseases. With respect to energy and fat balance, physical activity facilitates the equilibrium between energy intake and expenditure as well as between fat intake and fat oxidation. When combined ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:10.1139/y05-132
更新日期:2006-02-01 00:00:00
abstract::The aim of this study was to investigate the effects of melatonin on rat gastric fundus smooth muscle. Melatonin (10(-4) to 10(-3) M) had no effect on the basal tone of gastric smooth muscle. After precontraction with carbachol (10(-6) M) or serotonin (10(-7) M), melatonin caused a concentration dependent inhibitory a...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:
更新日期:2000-10-01 00:00:00
abstract::The effects of barbiturates on human platelet function are not fully understood. Since we have already revealed the effects and mechanisms of thiopental, thiamylal, and pentobarbital in platelets, the present study attempted to elucidate (i) the effects of other barbiturates on human platelet aggregation, (ii) the und...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y03-075
更新日期:2003-08-01 00:00:00
abstract::Normal mammalian sexual maturation and reproductive functions require the integration and precise coordination of hormones at the hypothalamic, pituitary, and gonadal levels. Hypothalamic gonadotropin-releasing hormone (GnRH) is a key regulator in this system; after binding to its receptor (GnRHR), it stimulates de no...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:
更新日期:2000-12-01 00:00:00
abstract::Connexin43 has been recognized as forming gap junctions in Leydig cells. However, previous work has shown that mouse Leydig cells lacking this connexin do not suffer any limitation of their ability to produce testosterone when stimulated with luteinizing hormone. The objective of this study was to identify additional ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2012-0385
更新日期:2013-02-01 00:00:00
abstract::Cyclophosphamide (CP) is an antineoplastic drug that induces kidney damage via producing oxidative stress. Carvacrol (CAR) has antioxidative effect and we postulated that it can be protective against CP-induced nephrotoxicity. Six groups (n = 7) of rats (control, 100 mg/kg CP, CP+5 mg/kg CAR, CP+10 mg/kg CAR, 5 mg/kg ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2016-0450
更新日期:2017-07-01 00:00:00
abstract::Cardiac adenosine receptors are coupled to adenylate cyclase inhibition. In the guinea pig heart, the relative agonist potencies observed for adenylate cyclase inhibition were R-N6-phenylisopropyladenosine (R-PIA) = N6-cyclohexyladenosine greater than 5'-N-ethylcarboxamidoadenosine much greater than S-PIA. In both atr...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y86-252
更新日期:1986-12-01 00:00:00
abstract::Intrinsic regulation of hepatic blood flow is mediated only through the hepatic artery because the liver is not able to directly regulate portal vein blood flow. Hepatic metabolic activity does not affect hepatic artery flow. Although the hepatic artery is affected by sympathetic nerves and blood-borne agents, the int...
journal_title:Canadian journal of physiology and pharmacology
pub_type:
doi:
更新日期:1996-03-01 00:00:00
abstract::Microglial inflammation, involved in the occurrence and development of sepsis-associated encephalopathy, exhibits upregulation of proinflammatory cytokine and proinflammatory enzyme expression, leading to inflammation-induced neuronal cell apoptosis. TIR domain containing adaptor molecule-2 (TICAM-2) participates in l...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2019-0699
更新日期:2020-11-01 00:00:00
abstract::Nitric oxide (NO) production occurs through oxidation of the amino acid L-arginine by NO synthase (NOS). NO inhibits platelet activation by increasing the levels of cyclic guanosine monophosphate (cGMP), thus maintaining vascular homeostasis. Our group previously demonstrated (da Silva et al. 2005) an enhancement of t...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y10-111
更新日期:2011-02-01 00:00:00
abstract::A systematic study has been performed in various segments of the intestine and in the urinary bladder of the mouse to identify tissues that respond to kinins and possess B1 and (or) B2 receptors. The stomach was found to contain B1 and B2 functional sites that show pharmacological profiles compatible with B1 and B2 re...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y95-240
更新日期:1995-12-01 00:00:00
abstract::The effect of various doses of i.p. injection of the adenosine receptor agonist (R)-phenylisopropyladenosine (R-PIA), ranging from nanomolar to micromolar concentrations, on plasma levels of free fatty acids, glucose, insulin, glucagon, ACTH, and corticosterone was examined in 200-g male rats. At the lowest dose of R-...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y94-018
更新日期:1994-02-01 00:00:00
abstract::Activity-related transient changes in extracellular K+ concentration ([K+]c), extracellular pH (pHc), and extracellular volume (EC volume) were studied by means of ion-selective microelectrodes in the adult rat spinal cord in vivo and in neonatal rat spinal cords isolated from pups 3-14 days of age. Repetitive electri...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:10.1139/y92-276
更新日期:1992-01-01 00:00:00
abstract::Administration of naloxone to morphine-dependent rats results in an elevation of tail skin temperature and a fall in core temperature. Previous studies have demonstrated a role of the adrenal gland in the thermal responses that accompany morphine withdrawal in the rat. In the present study, experiments were designed t...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y92-151
更新日期:1992-08-01 00:00:00
abstract::Pertussis toxin (PTX) is a heterohexameric protein, which is divided into subunits A and B. The A-subunit (protomer) possesses adenine diphosphate (ADP) ribosyltransferase activity, and the B-oligomer confers cell surface binding specificity on the toxin. By virtue of the ADP-ribosylation activity in the A-subunit, PT...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-74-5-559
更新日期:1996-05-01 00:00:00
abstract::Using conventional intracellular microelectrode techniques, the membrane potential (Em) of vascular smooth muscle cells in isolated segments of thoracic rat aorta was measured. The influence of exogenous and of endothelium-derived nitric oxide on the Em was assessed, and the involvement of glibenclamide-sensitive chan...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:
更新日期:1997-12-01 00:00:00
abstract::17 beta-Hydroxy-11 beta(4-dimethylaminophenyl)-17 alpha-(1-propynyl)estra-4, 9-dien-3-one (RU486) inhibited the in vitro development of different stages of mouse preimplantation embryos under study. Two-celled embryos, morulae, and early blastocysts were obtained from B6D2F1 mice. The embryos were grown in Ham F-10 nu...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y90-220
更新日期:1990-11-01 00:00:00
abstract::While conducting studies on the prevention of mortality from acute iron intoxication in rats, diazepam, given to prevent animal suffering, was observed to be associated with reduced mortality in a limited number of animals. The objective was to assess whether diazepam reduces mortality following acute iron intoxicatio...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-76-9-895
更新日期:1998-09-01 00:00:00