Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PHARMACOLOGY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources
PubMed1988

Progress in understanding the relationship between the pharmacological effects of nicotine and human tobacco dependence.

The present paper is intended to serve as an introduction to the series of eight papers which follow in this issue of Pharmacology Biochemistry and Behavior. A brief historical review of research that is at the root of much recent progress is provided in the present paper. In addition, we provide some data which illustrates the scope of tobacco-related research, world wide, in an effort to provide a perspective as to the vast amount of research activity that is currently in progress. Seven of the papers which follow were presented at a symposium held under the auspices of the American Society for Pharmacology and Therapeutics in 1986. Taken together, these papers are intended to provide new data and to review major areas of pharmacologic research relevant to the understanding and treatment of tobacco dependence. The topics include the behavioral and physiologic mechanisms by which the effects of nicotine are mediated, metabolic aspects of nicotine kinetics, and genetic determinants of responses to nicotine. The final paper is a discussion of the implications of these recent data for the pharmacologic treatment of tobacco dependence.

History, 19th Century↗
PubMedDate not supplied

Phosphatidylserine counteracts physiological and pharmacological suppression of humoral immune response.

Phosphatidylserine (PS) is a necessary cofactor for protein kinase C (PKC) activation, and changes in the synthesis of PS have been shown to participate in the mechanism(s) involved in the transmembrane signaling of interleukin 1 (IL-1). In view of the age-associated defects in T-cell functions, in the present study we have addressed the question of whether an in vivo treatment with PS might interfere with such processes. Furthermore, the effect of an in vitro treatment with PS in human peripheral blood monocytes (PBMC) or splenocytes activated with a lectin mitogen, on the expression of IL-2 receptor, was assessed. While the process of ageing was accompanied by a marked decline of humoral response monitored by anti-BSA antibodies (of the IgG class) production, following immunization with BSA in complete Freund adjuvant, chronic treatment with PS (50 mg/kg, in drinking water), reversed this effect, raising specific antibody titers to levels practically indistinguishable from those measured in young animals. Pharmacological depression of humoral immune response induced by a treatment of adult animals with dexamethasone was similarly reversed by a chronic treatment with PS. While only a pharmacological concentration (10(-5) M) of PS significantly increased IL-2 receptor expression in activated human PBMC, simultaneous treatment of PBMC with inactive doses of PS and the pharmacological activator of PKC (phorbol myristate acetate, PMA, 10(-8) M) resulted in a synergistic stimulation of Tac+ cells. Furthermore, in cultures of rat splenocytes PS (10(-6) M) significantly stimulated the expression of IL-2 receptor, and concomitant addition of PS (10(-7) M) to Con A-stimulated splenocytes produced a significant potentiation of IL-2 receptor induction. The present results indicate that in vivo treatment of ageing animals with the specific phospholipid PS is able to reverse the physiological decline of the humoral immune response induced by the ageing process. Moreover, treatment of young rats with PS reversed the pharmacological associated depression of specific antibody production. The in vitro effects of the phospholipid on human PBMC and rat splenocytes might suggest that PS is implicated in T-cell activation through its action on IL-2 receptor.

Aging↗
PubMedDate not supplied

Pharmacological examination of cholecystokinin (CCK-8)-induced contractile activity in the rat isolated pylorus.

The actions of cholecystokinin (CCK) in the production of a satiety-like state have been suggested to be mediated via receptors for CCK which are located in the pylorus. We investigated the actions of CCK and other pharmacological agents upon the isolated rat pylorus in vitro. We used the change in isometric tension of the tissue preparation (contraction amplitude) as the measure of the effects of the pharmacological agents. Cholecystokinin COOH-terminal octapeptide (CCK-8) was observed to elicit contraction in a dose-dependent manner, with the half-maximal dose (ED50) in the vicinity of 1 nM. Rapid desensitization to CCK was observed. The contraction amplitude was atropine-independent, and was not significantly antagonized by a wide variety of other pharmacological agents. The Na+-channel blocker tetrodotoxin was without effect upon contractile amplitude, as was the K+-channel blocker 4-aminopyridine, except at very high concentrations. Neurotensin, bombesin, and the substance P and bombesin antagonist spantide all elicited contraction in the isolated tissue; neurotensin had a similar potency to CCK-8 and bombesin was 10-15-fold less potent than CCK-8. Unsulfated CCK-8 was at least 170-fold less potent than sulfated CCK-8 and tetragastrin was at least 500-fold less potent than CCK-8. These results suggest that pyloric CCK receptors, which appear to have a pharmacological profile typical of peripheral CCK receptors, may have a physiological role in the peptidergic control of gastric emptying in the rat.

Animals↗
PubMed1988

Pharmacology of the glutamate receptor.

Glutamate is a potent candidate of the excitatory transmitter at the invertebrate NMJ and the synapse of the vertebrate CNS. But pharmacological studies have not been enough to prove that glutamate functions as an excitatory neurotransmitter. During the past 10 years, we have been studying the effects of various compounds which demonstrate the glutamate blocking action, but the glutamate responses are more effectively blocked by the drugs than the nerve-evoked synaptic response. A marked difference was revealed by TI-233, the minimum concentration of TI-233 on EJP being about a hundred times greater than the minimum threshold concentration on the glutamate-induced responses. The subsequent studies demonstrated that the action of TI-233 was able to be explained by the open channel block of the glutamate-activated ion-channel. The difference does not confute the hypothesis that glutamate is the natural transmitter substance at the crayfish NMJ, notwithstanding the fact that the action of the transmitter candidate on the postsynaptic membrane must be identical in every respect with that of the transmitter. Once something potentially useful has been found it is necessary to know not only what a substance does but how well it does it, so that comparisons can be made and better drugs discovered. Our first task therefore was to find a powerful glutamate blocker. Recently, as a result of synthesizing a series of compounds on the base of the structure-activity relationship in drug design, a series of compounds was found to reduce markedly glutamate responses at the crayfish NMJ and the mammalian central neurones at extremely low concentrations. In addition, a novel potent excitatory amino acid, acromelic acid, was found. This compound markedly excites the crayfish opener muscle and the mammalian central neurones. Agonists and antagonists have provided a very useful tool for neuroscience research, and findings of these new pharmacological tools will lead to progress in pharmacological studies to elucidate the function of glutamate in the body, in addition to other established compounds. The recent advances in our limited understanding of pharmacology of the glutamate receptor are discussed here.

2-Amino-5-phosphonovalerate↗
PubMed1996

Pharmacological profile of benzodiazepine site ligands with recombinant GABAA receptor subtypes.

Using [3H]flumazenil as a probe we investigated how benzodiazepine site pharmacology of alpha beta gamma ternary combinations of GABAA receptors can be influenced upon expression of different isoforms of alpha, beta and gamma subunits. The nature of the beta subunit did not alter the pharmacology of this site in that the affinities of alpha 5-containing GABAA receptors for various benzodiazepine modulatory ligands were essentially unchanged upon a comparison of different beta-variant forms (alpha 5 beta 1 gamma 2, alpha 5 beta 2 gamma 2 and alpha 5 beta 3 gamma 2). In contrast, both alpha and gamma variants contributed to notable differences in benzodiazepine site pharmacology. Thus alpha 1 beta 2 gamma 2, alpha 3 beta 2 gamma 2 and alpha 5 beta 2 gamma 2 receptors showed high, intermediate and low affinities for zolpidem, respectively. Exchanging gamma 2 for gamma 3 reduced the affinities of alpha 1 beta 2 gamma and alpha 3 beta 2 gamma receptors for zolpidem by factors of > 150 and > 5.8, respectively. The alpha 1 beta 2 gamma 3, alpha 3 beta 2 gamma 3 and alpha 5 beta 2 gamma 3 receptors exhibited, in contrast, higher affinity for CL218872 than their corresponding gamma 2 receptors. The information on these different recombinant GABAA receptor pharmacological profiles should help in the elucidation of native GABAA receptor subtype diversity.

Animals↗
PubMed2004

Molecular pharmacology of the ovine melatonin receptor: comparison with recombinant human MT1 and MT2 receptors.

The variations of the pharmacological properties of melatonin receptors between different mammalian species in transfected cell lines have been poorly investigated. In the present study, melatonin analogues have been used to characterize the pharmacology of the recombinant ovine melatonin receptor (oMT1) expressed in CHO cell lines and the native oMT1 from the pars tuberalis (PT). Studies with selective ligands on native and transfected oMT1 showed similar properties for binding affinities [r2(PT/CHO) = 0.85]. The affinities and the functional activities of these ligands were compared with the human receptors (hMT1 or hMT2) expressed in CHO cells as well. The oMT1 and hMT1 receptors had similar pharmacological profiles (r2=0.82). Nevertheless, some of the selective compounds at the human receptor presented a reduced affinity at the ovine receptor. Furthermore, some compounds showed marked different functional activities at oMT1 vs. hMT1 receptors. Our findings demonstrated differences in the pharmacological properties of melatonin receptors in ovine and human species.

Animals↗
PubMed2005

Non-pharmacologic approaches to graft-versus-host prevention.

Allogeneic transplant offers a curative option for selected hematological malignancies and improved disease free survival in those where cure is not possible. For patients in these categories, Graft-versus-host disease (GVHD) occurs often and is a significant cause of morbidity and mortality following transplantation. Pharmacological immunosuppression has considerable toxicity and controls GVHD in about 75% of transplant recipients when used in combination and continually. Thus, there is the need for viable and non-toxic alternatives for GVHD prevention and this is the impetus for seeking novel non-pharmacological strategies. Most techniques directed to this end are based on various permutations of T-cell depletion. Total T-cell depletion was the first graft engineering strategy employed but while beneficial, it was associated with delay in engraftment and early relapses. Modern depletion and adoptive immunotherapy techniques are directed toward specific subsets of T-cells which include alloreactive, naive, NK cells, T-helper and cytotoxic T-cells. While large bodies of preclinical evidence attest to the efficacy of currently available non-pharmacological prevention techniques, such is not the case with vigorous clinical trials. Where available, the proven non-pharmacological prevention techniques are yet to be fully interwoven into the patient care arena. Integration of available strategies and continuing research are therefore acutely needed to improve the chronic morbidity and mortality seen with both allogeneic transplant-associated GVHD and the use of pharmaceutical immunosuppressants.

Graft vs Host Disease↗
PubMed2004

Brain temperature fluctuations during passive vs. active cocaine administration: clues for understanding the pharmacological determination of drug-taking behavior.

While it is generally assumed that cocaine self-administration (SA) is determined and maintained by the pharmacological actions of cocaine in the brain, it is also a drug-motivated and drug-reinforced goal-directed behavior, which is determined by concurrent learning and behavioral performance. To dissociate the contributions of pharmacological and behavioral factors to cocaine SA, it is important to compare cocaine SA with its pharmacological copy, passive intravenous (iv) cocaine administration. This approach was employed in the present study with respect to brain temperatures, a dynamic parameter that reflects metabolic neural activity and shows consistent fluctuations during cocaine SA. Passive cocaine injections performed with the same dose/pattern as SA induced brain temperature fluctuations similar in many ways to those in behaving animals. The initial passive drug administration of a session elevated brain temperature, while subsequent repeated injections were associated with biphasic temperature fluctuations that maintained at a relatively stable plateau. Although the magnitude of these fluctuations was twofold smaller than in behaving animals, passive animals had the same pattern; brain temperatures transiently decreased after cocaine injection, then increased, and were inhibited again by the next cocaine infusion. In contrast to self-administering animals, rats exposed to passive cocaine injections had significantly lower basal temperatures and never showed gradual temperature increases preceding the initial injection. Striking differences in brain temperature dynamics seen in the beginning of a session suggest that during the development of drug-taking behavior the initial cocaine-induced neural activation becomes transformed into behavior-related "anticipatory" neural activation (motivational arousal) that fuels drug seeking and results in the initial drug intake. While this activation is triggered by drug-related cues and enhanced by the initial cocaine intake, subsequent highly cyclical cocaine intakes appear to be primarily pharmacologically determined.

Animals↗
PubMed2004

Versatile pharmacological actions of YC-1: anti-platelet to anticancer.

Since the first article on YC-1 was published in 1994, it has been popularly used as a pharmacological tool to activate soluble guanylate cyclase and to increase cyclic GMP levels in cultured cells or isolated tissues. In terms of the pharmacological actions of YC-1, previous studies tend to be limited to it inhibition of platelet aggregation and vascular concentration. However, recent studies have demonstrated that YC-1 has versatile pharmacological effects other than the anti-platelet and vasodilatory effects. In particular, two recent reports suggest that YC-1 could be developed as a new class of anticancer agent for rapidly growing solid tumors, because it inhibits hypoxia-inducible factor 1 (HIF-1) activity, and has been reported to halt tumor growth in vivo. We here review the cyclic GMP-dependent and independent pharmacological actions of YC-1, and its anti-HIF-1, anticancer effect.

Animals↗
PubMed2006

The pharmacology and regulation of T type calcium channels: new opportunities for unique therapeutics for cancer.

T type calcium channels are implicated in a fascinating array of physiological and pathophysiological phenomena, as reviewed extensively in this issue of Cell Calcium. It is also evident from this timely collection of papers that knowledge about T channels is nascent. This creates the exciting potential to explore an uncharted territory for new insights into important physiological processes and associated diseases. Equally exciting and perhaps more important is the opportunity to exploit the developing understanding of T channels to design new therapeutic approaches to diseases that are now intractable to varying degrees. This review will focus on the controversy surrounding the proposed novel functions for and means of regulation of T type Ca2+ channels, particularly with regard to the potential role of pharmacologic modulation of T type Ca2+ channels in cytostatic cancer chemotherapy. In addition, we will concentrate on recent studies of the molecular pharmacology and physiology of T type channels, since these areas (molecular pharmacology [T.N. Heady, J.C. Gomora, T.L. Macdonald, E. Perez-Reyes, Molecular pharmacology of T-type Ca2+ channels, Jpn. J. Pharmacol. 85 (2001) 339-350.]; physiology [E. Perez-Reyes, Molecular physiology of low-voltage-activated t-type calcium channels, Physiol. Rev. 83 (2003) 117-161.]) have been very well-reviewed and the reader is referred to these authoritative sources.

Calcium↗
PubMed2004

Pharmacological chaperone action on G-protein-coupled receptors.

An increasing number of genetic diseases are found to result from mutations that lead to retention of the affected proteins in the endoplasmic reticulum, where they are recognized as misfolded by the quality control system. Several of these conformational diseases involve mutations in G-protein-coupled receptors. Recent studies demonstrated that pharmacologically selective compounds, termed pharmacological chaperones, can stabilize the misfolded receptors, facilitating their export from the endoplasmic reticulum to the plasma membrane, where they can be active. Such functional rescue suggests that pharmacological chaperones could represent novel therapeutic agents for the treatment of conformational diseases. Although only a few examples are currently available, the observation that pharmacological chaperones can also favour the folding of wild-type G-protein-coupled receptors indicates that these compounds could have wide applications.

Animals↗
PubMed2006

Molecular cloning and pharmacological characterization of serotonin 5-HT(3A) receptor subtype in dog.

In order to establish if the canine 5-hydroxytryptamine type 3A (5-HT(3A)) receptors share the pharmacological profile with human 5-HT(3A) receptors, we cloned and performed a molecular pharmacological characterization of the canine 5-HT(3A) receptor. The 5-HT(3A) cDNA was cloned from canine brain by polymerase chain reaction amplification. It encodes a 483 amino acid peptide that exhibits from 80% (mice) to 90% (ferrets) identity to other sequenced mammalian 5-HT(3A) receptors. The receptor agonists 5-hydroxytryptamine (5-HT) and meta-chlorophenylbiguanide (mCPBG) showed little differences between the two species, whereas 2-methyl-5-hydroxytryptamine (2-Me-5-HT) was ten times weaker at canine receptors than at human receptors. The potencies at the canine 5-HT(3) receptors were 9.9 microM (5-HT), 79 microM (2-Me-5-HT) and 0.8 microM (mCPBG). The selective, competitive receptor antagonist ondansetron was ten times more potent at human receptors compared to canine receptors (K(b)=0.9 nM), while (+)-tubocurarine was 1000-fold more potent at canine receptors (K(b)=3.0 nM) than at human receptors. Examination of the presumed ligand binding extracellular domain revealed one residue, where the canine receptor differs from all previously characterized 5-HT(3A) receptors, i.e. other species contain a conserved Trp(195), whereas the canine orthologue contains a Leu(195). To address the differences in potencies at the human and canine 5-HT(3A) receptors seen in this study, we introduced a L195W point mutation in the canine orthologue. Data showed that the 195 residue can affect receptor agonist potency and efficacy as well as antagonist potency, but did produce a pharmacological profile identical to the human orthologue. We therefore conclude that position 195 is strongly involved in the receptor-ligand interaction, but additional residues must contribute to the overall pharmacological profile.

Amino Acid Sequence↗
PubMed2006

Pharmacological separation between peripheral and central functions of cyclooxygenase-2 with CIAA, a novel cyclooxygenase-2 inhibitor.

There are many reports concerning the physiological and pathological involvement of cyclooxygenase (COX)-2 in the central nervous system and peripheral tissue cells. Selective COX-2 inhibitors that mainly distribute peripherally have not been reported thus far. Therefore central and peripheral roles of COX-2 remain classified pharmacologically. In this study, in vivo pharmacological profiles of CIAA ([6-chloro-2-(4-chlorobenzoyl)-1H-indol-3-yl]acetic acid), a novel selective COX-2 inhibitor which distributes at higher concentrations in plasma than in brain, were compared with those of well-known selective COX-2 inhibitors, celecoxib and rofecoxib. Additionally, the possibility of pharmacological separation between peripheral and central actions of COX-2 with the inhibitors was investigated. CIAA selectively inhibited COX-2 activity compared with COX-1 in in vitro assays with rat whole blood. The compound exhibited lower brain penetration and higher plasma concentration (the brain/plasma concentration ratio was approximately 0.02) than celecoxib and rofecoxib after oral administration. Therefore, CIAA is mainly expected to act peripherally. Edema and prostaglandin E2 (PGE2) production in Carrageenan-injected rat paws, and pyrexia and PGE2 production in the brain in lipopolysaccharide (LPS)-injected rats were measured in in vivo experiments. CIAA exhibited lower ratios of anti-pyretic/anti-edematous activities and of inhibitory activities of PGE2 production in brain/paw than those of celecoxib and rofecoxib, and these ratios well-reflected brain/plasma concentration ratios. In conclusion, we discovered a novel selective COX-2 inhibitor, CIAA, which distributes at higher concentrations in plasma than in brain, which would make possible the pharmacological separation of the peripheral and central functions of COX-2.

Animals↗
PubMed2004

Effect of specific immunotherapy added to pharmacologic treatment and allergen avoidance in asthmatic patients allergic to house dust mite.

BACKGROUND: Although several studies support the efficacy of specific immunotherapy in allergic asthma, its benefit compared with that of standardized pharmacologic intervention remains unknown. OBJECTIVE: A double-blind, placebo-controlled trial in 72 patients with mild-to-moderate asthma and allergy to house dust mite (HDM; Dermatophagoides species) was conducted to assess the effects of specific immunotherapy added to guideline-adjusted pharmacologic treatment and allergen avoidance. METHODS: After 1 observational year of pharmacologic treatment and standard measures of HDM avoidance, 2 groups of asthmatic subjects were randomly assigned to receive specific immunotherapy consisting of subcutaneous injections of either a mixture of Dermatophagoides pteronyssinus and Dermatophagoides farinae vaccine (n=41) or placebo (n=31) for 3 years. Medications were adjusted every 3 months according to the Global Initiative for Asthma guidelines. RESULTS: The adjustment of treatment was associated with a reduction in asthma symptom scores in all subjects. The addition of specific immunotherapy was associated with a decrease in the number of subjects requiring rescue bronchodilators, an increase in morning and evening peak expiratory flow, and a reduced skin sensitivity to HDM extracts. The addition of specific immunotherapy had no significant effects on the cumulative dose of inhaled corticosteroids, asthma symptoms, lung volumes, or bronchial responsiveness to methacholine. CONCLUSION: These results suggest that specific immunotherapy added to pharmacologic treatment and HDM avoidance provides marginal but statistically significant clinical benefits, possibly by reducing the allergic response of asthmatic patients sensitized to HDM.

Administration, Inhalation↗
PubMedDate not supplied

Determinants of women's decision making on whether to treat nausea and vomiting of pregnancy pharmacologically.

Nausea and vomiting of pregnancy (NVP) affects up to 80% of all women to some degree during their pregnancies. Diclectin (doxylamine and pyridoxine [vitamin B6]) has been on the Canadian market for many years and is indicated as the drug of choice for the treatment of NVP. However, some women choose not to treat NVP with pharmacologic measures, perhaps due to a persistent fear of teratogenic risk. The objective of this study was to determine the factors that influence a woman's decision not to treat NVP with pharmacologic measures. Fifty-nine women recruited from the Motherisk Nausea and Vomiting Helpline completed a questionnaire. All were informed that Diclectin was considered safe for use during pregnancy. At a follow-up telephone call, 34% were not using any pharmacologic treatment, and of those who were taking the drug, 26% were using less than the recommended dose. Reasons cited for not using the medication were insufficient safety data, preference for non-pharmacologic methods, and being made to feel uncomfortable by the physician. Of the women who did use Diclectin, the most convincing reassuring information that it was safe to use came from friends and family. Many other factors play a large role in a women's decision making.

Adult↗
PubMed2003

Genetic and pharmacological aspects of histamine H3 receptor heterogeneity.

Histaminergic H3 receptors modulate the release of neurotransmitters within the CNS and periphery. Ligands for these receptors have potential clinical utility in a variety of disease states. However, the pharmacological characteristics of these receptors have been enigmatic for more than a decade because of the diversity of pharmacological effects observed with the limited number of heretofore-available compounds. Recent cloning of the H3 receptor has revealed interspecies differences in the protein sequences in key regions, the existence of splice variants that differ in composition between species, and potential differences in signal transduction processes between either different tissues and/or species. This review attempts to summarize these findings within the context of the molecular biological and pharmacological data accumulated to date. Also, we suggest a nomenclature strategy to reduce potential confusion that has arisen from different naming systems used by various investigators. While some facets of this genetic and pharmacological diversity help to rationalize various aspects of H3 receptor heterogeneity, there remains an insufficient repertoire of selective ligands, assays, or other measures to completely resolve all components of this diversity. The promise of newly available tools to further explore H3 receptor function may provide the insight to bring the promised clinical potential of H3 receptor ligands to realization.

Amino Acid Sequence↗
PubMed2005

The tail suspension test as a model for assessing antidepressant activity: review of pharmacological and genetic studies in mice.

Since its introduction almost 20 years ago, the tail suspension test has become one of the most widely used models for assessing antidepressant-like activity in mice. The test is based on the fact that animals subjected to the short-term, inescapable stress of being suspended by their tail, will develop an immobile posture. Various antidepressant medications reverse the immobility and promote the occurrence of escape-related behaviour. This review focuses on the utility this test as part of a research program aimed at understanding the mechanism of action of antidepressants. We discuss the inherent difficulties in modeling depression in rodents. We describe how the tail suspension differs from the closely related forced swim test. Further, we address some key issues associated with using the TST as a model of antidepressant action. We discuss issues regarding whether it satisfies criteria to be a valid model for assessing depression-related behavioural traits. We elaborate on the tests' ease of use, strain differences observed in the test and gender effects in the test. We focus on the utility of the test for genetic analysis. Furthermore, we discuss the concept of whether immobility maybe a behavioural trait relevant to depression. All of the available pharmacological data using the test in genetically modified mice is collated. Special attention is given to selective breeding programs such as the Rouen 'depressed' mice which have been bred for high and low immobility in the tail suspension test. We provide an extensive pooling of the pharmacological studies published to date using the test. Finally, we provide novel pharmacological validation of an automated system (Bioseb) for assessing immobility. Taken together, we conclude that the tail suspension test is a useful test for assessing the behavioural effects of antidepressant compounds and other pharmacological and genetic manipulations relevant to depression.

Analysis of Variance↗
PubMed2006

In vivo mapping of functional connectivity in neurotransmitter systems using pharmacological MRI.

Pharmacological MRI (phMRI) methods map the hemodynamic response to drug challenge as a surrogate for changes in neuronal activity. However, the central effects of drugs can be complex and include activity at the primary site of action, downstream effects in other brain regions and direct effects on vasculature and neurovascular coupling. Univariate analysis, normally applied to phMRI data, does not discriminate between these effects, and can result in anatomically non-specific activation patterns. We analysed inter-subject correlations in the amplitude of the slow phMRI response to map functionally connected brain regions recruited in response to pharmacological challenge. Application of D-amphetamine and fluoxetine revealed well-defined functional structure underlying the widespread signal changes detected via standard methods. Correlated responses were found to delineate key neurotransmitter pathways selectively targeted by these drugs, corroborating a tight correspondence between the phMRI response and changes in neurotransmitter systems specific to the pharmacological action. In vivo mapping of correlated responses in this way greatly extends the range of information available from phMRI studies and provides a new window into the function of neurotransmitter systems in the active state. This approach may provide new important insights regarding the central systems underlying pharmacological action.

Animals↗