Regarding the average values of all participants over nine minute

Regarding the average values of all participants over nine minutes of ECC, the no-flow time for 30:2 was significantly less than for 15:2. All ECC data comparing 15:2 and 30:2 are presented in Table ​Table2.2. All participants decompressed the chest incompletely during ECC (Table ​(Table2).2). Therefore, for both CVRs the compression amplitude was significantly lower for male and female participants as compared to the compression depth (data not shown, p < 0.001; t-test for paired data). As the decompression depth, however, did not change over the

nine minutes of ECC, further analyses were focused on both the compression depth and compression rate. Table 2 Values of learn more external chest compression variables for the participants as means Inhibitors,research,lifescience,medical over a nine-minute period, for all participants and differentiated by gender. Minute-to-minute analysis of all participants showed a significant decrease Inhibitors,research,lifescience,medical in compression depth starting from minute four (94.8% of minute 1) for 15:2 (p < 0.05) and from minute three (95.3% of minute 1) for 30:2 (p < 0.05). Furthermore, female participants compressed more rapidly (p = 0.1) and significantly Inhibitors,research,lifescience,medical more shallowly (p = 0.04) than male participants (Figures ​(Figures2A2A and ​and2B2B). Figure 2 Minute-to-minute compression depth (A) and rate (B) during external chest compression performed

by male (n = 30) and female (n = 10) participants. A: Inhibitors,research,lifescience,medical Compression depth, male vs. female: p = 0.04; B: Compression rate, male vs. female: p = 0.1. Squares … Separation based on biometric data For the entire cohort, we found a significant correlation between gender and BMI as well as gender and HR75. Furthermore, a significant correlation between BMI and HR75 was seen (r = -0.58), potentially indicating BMI as an epiphenomenon of good physical fitness due to an increased muscle mass. Finally, significant differences in the quality of ECC were found between female and male participants with regards

Inhibitors,research,lifescience,medical to compression depth and rate (see Table ​Table2).2). We therefore analysed female and male participants separately. In addition, male and female participants were differentiated into groups with higher and lower values of BMI and HR75. The calculated median selleck kinase inhibitor of each variable was set as the threshold between the high and low groups. Thus, half of the cohort (15 males and five females) represented the highs and the lows. The median values were as follows: For male participants BMI = 25.4 kg/m2 and HR75 = 130.5 bpm; for female participants BMI = 20.4 kg/m2 and HR75 = 167.0 bpm. In the following, for male participants lower BMI refers to participants with a BMI below 25.4 kg/m2; a higher BMI refers to participants with a BMI above 25.4 kg/m2. For females, a lower BMI refers to participants with a BMI below 20.4 kg/m2 and a higher BMI to participants with a BMI above 20.4 kg/m2. We found no significant correlation between BMI and HR75 (r = 0.33) for male participants.

Each measure was determined for each successive 1-min time bin T

Each measure was determined for each successive 1-min time bin. The automated video trackers were able to follow the flies for a minimum of 98% of the time. The analyzed data were imported into StatView v5.0.1 (SAS Institute, Cary, NC) or MATLAB (The MathWorks, Inc., Natick, MA) for statistical analysis. In all our statistical analysis, the threshold for P-value was 0.05.

Inhibitors,research,lifescience,medical In the hourglass-shaped arena, trajectories that passed the horizontal midpoint of the central chasm were counted horizontal transitions (HTs). These trajectories typically result in movement between the chambers. Those trajectories that crossed vertical midpoint in the gap of the 2-cm central chasm were taken as vertical transitions (VTs). A diagonal movement though the chasm was record as both an HT and a VT. The VT index was computed as (number of VT−number of HT)/(total number of transitions). Turning angle calculation The Ethovision Tracking system (Noldus Information Technology) Inhibitors,research,lifescience,medical records XY position of the fly at 30 frames per second. To calculate turning angles of flies for different sampling rates, we use MATLAB to reconstruct the trajectory of flies at different sampling rates. Three consecutive positions were used to calculate a turn angle using a simple law of cosines rule. Simulating Inhibitors,research,lifescience,medical movement in an

open-field arena The Flymatron simulation software was written in Visual Basic and allows the modeling of the effect of turn angles on the spatial orientation of the fly in arenas Inhibitors,research,lifescience,medical of any shape. Flymatron

can load any type of arena and selleckchem 17-DMAG outputs the spatial positions of the fly for each iteration. An undirected network of nodes of a fixed size determined by user input (rows and columns) or the by the size of an arena image Inhibitors,research,lifescience,medical is first generated. In this network, there are no diagonal links between nodes. The user can alter the size and shape of the arena by making pixels below a fixed luminosity as wall nodes. The user can also input a set of different parameters that control the turn angle and movement distance of the fly. The two main parameters, field of vision and sight distance, limit the amount of turn angle and distance the fly can move in one iteration. Once the grid is created and the fly’s starting position and direction of motion are generated randomly, a set of candidate target points is determined based on the input parameters. These candidate Drug_discovery target nodes are then examined in the context of the network (environment) to exclude those that are not appropriate, such as if the target node is a wall, is unreachable (e.g., behind a wall), or is outside the network. If there are no candidate target nodes remaining, then the fly executes a random turn until there is a set of available candidate target points. On the availability of candidate target points, the fly resumes its movement as defined by the initial input parameters.

1,54 In two studies, 27% to 31% of individuals with BDD had been

1,54 In two studies, 27% to 31% of individuals with BDD had been completely housebound for at least

1 week due to BDD symptoms, and more than 40% had been psychiatrically hospitalized.52,55 Risk behaviors: suicidality, substance abuse, and violence Rates of suicidal ideation, suicide attempts, and completed suicide appear markedly elevated.79 Approximately 80% of individuals with BDD report past or current suicidal ideation, and about one quarter have attempted suicide, which is often Selleck Rho inhibitor attributed to BDD symptoms.42,50,52,79-81 In the only prospective study of the course of BDD, completed suicide was reported in 0.3% of cases per year.82 This Inhibitors,research,lifescience,medical finding should be considered preliminary, because the sample size was relatively Inhibitors,research,lifescience,medical small and the follow-up period was relatively brief; nonetheless, this suicide rate is markedly elevated. While caution should be used in comparing this rate

to that of other disorders, the standardized mortality ratio in this study is higher than that reported for nearly any other mental disorder.83 Approximately one third of people with BDD report violent behavior that they attribute primarily to BDD symptoms (eg, attacking someone or damaging property).1,84 Clinical impressions suggest that anger or violence may be fueled by anger about looking “deformed,” inability to fix the “defect,” delusions of Inhibitors,research,lifescience,medical reference (eg, believing that other people are mocking the “defect”), and feeling rejected by others because of the “defect.” In addition, anger or even violent behavior may be caused by dissatisfaction with cosmetic procedures. According to one survey, 12% of plastic surgeons said that they had been threatened physically by a dissatisfied Inhibitors,research,lifescience,medical BDD patient.85 Inhibitors,research,lifescience,medical There are occasional reports of individuals with probable BDD who attacked and even

killed their plastic surgeon after being distraught by the outcome of a cosmetic procedure.2 Many individuals with BDD abuse alcohol or drugs. In one study,86 48.9% of BDD participants were diagnosed with a lifetime substance-use disorder, with 42.6% reporting an alcohol-use disorder and 30.1% reporting a cannabis-use disorder. Onset of BDD preceded onset of a substance-use disorder by at least 1 year in 60% of http://www.selleckchem.com/products/byl719.html the participants, followed onset of the substance-use disorder in 19% of the participants, and began in the same year in 21%. When asked about the relationship between substance use and BDD symptoms, 68% said that BDD symptoms contributed to the substance use becoming problematic.86 Comorbidity BDD is often comorbid with other mental disorders. In the two largest phenomenology studies of individuals ascertained for BDD (n=293 and n=200), which assessed all participants with the Structured Clinical Interview for DSM,14 major depressive disorder was the most common comorbid disorder, with a lifetime prevalence of about 75% in both samples.

It is also known as the rescue-principle or the principle of non-

It is also known as the rescue-principle or the principle of non-abandonment

[65]. However, giving priority to the principle of equality in emergency [10] care situation is not an optimal strategy to realize efficient use of scarce resources. The principle of utility, on the other hand, holds that actions should be judged by their consequences and Inhibitors,research,lifescience,medical how far they produce the greatest net benefit among all those www.selleckchem.com/products/Imatinib(STI571).html affected. Or put simply, to do the greatest good for the greatest number. In fact, utilitarianism is the rationale for triage systems, insofar as they seek to use the available but scarce medical resources as efficiently as possible [11]. In itself, however, the principle of utility remains silent with regard to which goods or benefits are to be maximized [23]. In order to produce the greatest net benefit, we must have a clear account of which kinds of benefit are to be promoted. For instance, Inhibitors,research,lifescience,medical triage systems may seek to achieve the health benefits of survival (saving the most lives), restoration or preservation of function (by maximizing quality-adjusted life-years or disability-adjusted life-years), relief of suffering, and so on [10,23]. To maximize the chosen benefits overall, however, Inhibitors,research,lifescience,medical triage systems may dictate that treatments for some patients be delayed, often resulting in poorer outcomes for

those patients. Bad consequences for some may be justified if an action produces Inhibitors,research,lifescience,medical the greatest overall benefit. Triage systems recognize this because in emergency situations, the resources are scarce in relation to the needs of the patients. Consequently, the needs of some patients will be subordinated to those of others in order to maximize utility. Which one of the criteria will, in fact, maximize utility, depends on complex empirical aspects of the situation and on the triage officer’s assessment capacities. One particular criterion, however, is being

reflected in the third principle of justice, i.e. the Inhibitors,research,lifescience,medical principle of priority to the worst-off. Here, much depends on how one defines the worst-off group. Are they the most needy? The most urgent cases? Or the ones with the lowest prospects? Or even the poor and disenfranchised people who most often use the emergency departments because they have no other choice of receiving health care? [18] Suppose the worst possible outcome would be death [66]. Accordingly, the worst-off group would be the severely GSK-3 ill or injured people whose risk of death is highest, and for whom the likelihood of successful treatment is low, i.e. the ones at the edge of life and death. Guided by this principle, triage systems would give priority to treatment of this clearly disadvantaged group. However, it would be highly inefficient if maximizing the benefits to this group would imply investing a disproportionate share of scarce resources into a group of patients who are not likely to survive.

e , ≤$15,000) was negatively associated with antidepressant use,

e., ≤$15,000) was negatively associated with antidepressant use, but the level of education, private/veterans insurance or MAP coverage, family support, and disability

score were not significant factors. Of need factors, the HAMD score and pain ARRY-162 price medication intake were not significantly associated with antidepressant use but antianxiety medication intake was a significant factor. Table 3 Correlates of antidepressant intake: binary logistic regression results (N = 162) The OLS regression results (not shown in Table 3) found that the perceived effectiveness Inhibitors,research,lifescience,medical of antidepressants was negatively associated with being aged 70 or older (β = −0.321, t = −2.210, P = 0.031) and the HAMD score (β = −0.299, t = −2.320, P = 0.024). Sex and race/ethnicity were not significant correlates. However, caution is required in interpreting the results, given the small sample size. Discussion The study found that about half of the low-income, depressed, homebound older-adult participants were taking antidepressant medications. All predisposing factors (sex, age, Inhibitors,research,lifescience,medical and race/ethnicity) were Inhibitors,research,lifescience,medical significantly associated with the likelihood of antidepressant use, supporting H1a. Of the enabling factors, only income was a significant correlate. Of the need factors, severity of current depressive symptoms was not significantly

associated with antidepressant intake, partly because the study included only depressed participants. The cross-sectional data did not allow us to examine the severity of depressive symptoms prior to antidepressant use either. However, the finding that self-reported use of antianxiety

medication was positively associated with self-reported antidepressant use suggests the importance Inhibitors,research,lifescience,medical of comorbid anxiety and depression and associated symptom severity as a need factor. Thus, the logistic regression results did not support H1c and only partially supported H1b and H1d. The hypothesis regarding the factors associated with the participants’ perception of effectiveness of antidepressants was also partially supported Inhibitors,research,lifescience,medical as it was negatively associated with older age (70+) and higher HAMD scores, but it was not significantly associated with gender LY2228820 chemical structure and race/ethnicity. The negative relationship between age and antidepressant use appears to suggest an age cohort effect, with those aged 70 or older having a more negative predisposition toward antidepressant use than those aged 50–59. Based on the study’s finding that those aged 70 or older were also less likely to perceive their medications to be effective, some individuals in this age group may have stopped taking antidepressants. PCPs may also be reluctant to prescribe antidepressants to older patients, especially those with multiple medical conditions (Bruce et al. 2002; Ayalon et al. 2010). The finding may also reflect low-income, depressed, homebound older adults’ preference for nonpharmacological over pharmacological treatment.

However, previous studies assessing the potential of fMRI changes

However, previous studies assessing the potential of fMRI changes to serve as a marker for early pathology and for potential treatment effects in AD are still in a pilot stage including only small samples. Results need to be replicated in larger samples using prospective and longitudinal study designs. Magnetic resonance spectroscopy One common finding reported in the magnetic resonance spectroscopy (MRS) literature as associated with AD is a decrease in N-acetyl-aspartate concentration Inhibitors,research,lifescience,medical (NAA) and its ratio

to creatine (Cr).51-54 A positive correlation between NAA, and NAA/Cr, and Mini Mental State Examination (MMSE) scores in neurodegenerative disorders has also been reported.55 Inhibitors,research,lifescience,medical NAA is a free amino acid, present in the brain at relatively high concentrations (8 to 12 mM/kg wet weight). Its function is poorly understood, but it is believed to act as an osmolite, a storage form of aspartate, and a precursor of Nacetyl-aspartate -glutamate, Given that NAA is predominantly intraneuronal, it has been widely used as a marker of neuronal density.56 Observations suggesting that disruption of mitochondrial energy metabolism leads to a reversible drop in NAA,57 however, lead to the conclusion that Inhibitors,research,lifescience,medical NAA levels may more accurately reflect neuronal

dysfunction rather than neuronal loss. A second finding reported in the literature as associated with AD is an increase in the myo-Inositol (ml) concentration, as well as its ratio to creatine.54,58-59 ml is a cyclic sugar alcohol, whose role in the brain is not well understood. It is generally believed that ml is an essential requirement for cell growth, an osmolite, and a storage Inhibitors,research,lifescience,medical form for glucose.60 It has also been proposed as Inhibitors,research,lifescience,medical a glial cell marker. Normal concentrations of ml range from 4 to 8 mmol/kg wet weight. Given the importance of developing

surrogate markers for AD diagnosis, ways to improve the performance of MRS-based methods have been proposed. The use of metabolite tailored pulse sequences61,62 has been proposed for AD diagnosis and treatment. Such pulse sequences are optimized for measurement of some metabolites (eg, NAA and ml) while degrading performance for acquisition of data from others. Although improvements in data Cilengitide acquisition and quantification protocols are bound to significantly reduce measurement variability for MRS data, it is unlikely that such methods will ever acquire the sensitivity and specificity needed to diagnose or monitor treatment in AD on an individual patient basis. The limited chemical shift range for proton MRS (~5 ppm) leads to the www.selleckchem.com/products/Bicalutamide(Casodex).html existence of a very narrow range for chemical signatures of hundreds of aminoacids and chemical compounds found in human brains.

2), much higher than that observed when the two compounds were a

2), much higher than that observed when the two compounds were administered separately. Figure 2 Protective effects afforded by combined treatments with memantine, ifenprodil, and galantamine

against NMDA neurotoxicity in cultured rat cortical neurons. Treatment with galantamine (1 μmol/L)/memantine (0.1 μmol/L) or galantamine (1 … Galantamine exerts its neuroprotective effect via α7 and α4β2 nicotinic acetylcholine receptors Galantamine does not bind to NMDARs (Simoni et al. 2012). Therefore, the reported effect against the NMDA-induced toxicity cannot be ascribed to the inhibition of these receptors. Galantamine increases Inhibitors,research,lifescience,medical ACh concentration via inhibition of AChE. Inhibitors,research,lifescience,medical In addition, it has been reported that galantamine is an allosteric modulator of nAChRs (Maelicke and Albuquerque 2000; Samochocki et al. 2003). Therefore, we assessed the role of nAChRs by blocking the α7 and α4β2 nAChRs, which are the most affected nAChRs subtypes in AD. Administration of MCC, an α7 nAChR antagonist, partially blocked the neuroprotective effect of galantamine (5 μmol/L) in a concentration-dependent manner, reaching a maximal effect at 10 nmol/L (Fig. 3A). Similarly, DHBE, an α4β2 nAChR antagonist, attenuated

the protective effect of galantamine, although to a lesser extent than did MCC (Fig. 3B). To further test the possible role of α7 nAChR, we evaluated the effect of the α7 agonist ARR in directly potentiating the Inhibitors,research,lifescience,medical neuroprotective effect Inhibitors,research,lifescience,medical of memantine or ifenprodil (Fig. 3C). Our data show that ARR potentiated the effect of both memantine and ifenprodil, although to a lesser extent when compared with galantamine. Figure 3 Blockade of α7 or α4β2 nAChRs decreases

galantamine neuroprotection against NMDA toxicity, and activation of α7 nAChR with memantine or ifenprodil shows neuroprotective effect. Exposure Inhibitors,research,lifescience,medical of neuronal cultures to different … Finally, we treated cells with the memantine/galantamine combination and then with MCC and/or DHBE. Our results revealed a decreased potentiating effect of galantamine with either MCC or DHBE (Fig. 4A). When the two compounds were given simultaneously, the protective effect of the memantine/galantamine Anacetrapib combination was completely lost. These experiments were repeated with the ifenprodil/galantamine combination, obtaining similar results (Fig. 4B). Discussion Overactivation of NMDARs leads to neuronal death in different neurodegenerative conditions, including AD (Chen and Lipton 2006). Our results confirm previous data indicating that memantine prevents NMDA-induced excitotoxicity in rat neuronal cultures (Chen et al. 1992; Volbracht et al. 2006). Recent studies have suggested that memantine could preferentially block the extrasynaptic NMDARs, leaving untouched the synaptic receptors (Xia et al. 2010). It has been reported that extrasynaptic NMDARs are enriched of NR2B subunits (Thomas et al. 2006).

Structure of the striated muscle, i e ,

Structure of the striated muscle, i.e., cardiac and skeletal muscles, represents

thick and thin filaments. The main components of the thick and thin filaments are myosin and actin, respectively, and the thin filaments are inserted into, and tethered by, the Z-band in a square array with the sarcomeric filaments from Inhibitors,research,lifescience,medical the neighboring sarcomere (2). Because the force generated by contraction of sarcomere can be transmitted through a complex network of proteins in the Z-band, the Z-band plays various important roles in the cardiomyocytes, i.e., sarcomeric organization and force transduction in cardiac muscle (3). The Z-band also mediates functional link between sarcolemma and nuclear membrane (4). Because the

Z-band is important in establishing the Inhibitors,research,lifescience,medical mechanical coupling of the sarcomere, functional defects in the sarcomere or Z-band proteins might lead to cardiac Inhibitors,research,lifescience,medical dysfunction. Indeed, abnormalities in the cytoarchitectural proteins including sarcomere/Z-band components have been identified in ICM (5). This review will focus on the role of saromere and cytoskeletal Z-band proteins in the pathogenesis of ICM. Hypertrophic cardiomyopathy (HCM) HCM is the most prevalent click this hereditary cardiac disease (1:500 Inhibitors,research,lifescience,medical of the general population for the disease phenotype) and one of the major causes of sudden cardiac death in the young, characterized by left ventricular (LV) hypertrophy, usually with the presence of a small LV cavity, accompanied by Inhibitors,research,lifescience,medical myofibrillar disarrays and diastolic dysfunction (6, 7). From the first full description of HCM, in 1958, as “asymmetrical hypertrophy of the heart in young adults” including

a sib-case with sudden cardiac death (8), it has been suggested that this disease is inheritable. Indeed, 50-70% of HCM patients have apparent family histories of the disease, which is consistent with autosomal dominant inheritance, GSK-3 suggesting that genetic abnormalities cause HCM (6). The etiology of HCM, however, had been unknown until 1990 when a mutation in MYH7 encoding cardiac β-myosin heavy chain was, for the first time, identified in a multiple family with HCM. After the discovery of MYH7 mutation as the HCM gene, hundreds of mutations in more than 20 genes were reported in HCM and HCM-like diseases (Table ​(Table1).1).

The responsibility includes this related problem, if one is to ad

The responsibility includes this related problem, if one is to adequately care for the sick.” Compassion and understanding of our patients’ personal preferences remain essential parts of being a competent physician. We should consider our role of physician as a privilege

to be taken into a patient’s and their family’s life, entrusted with the most personal and private information regarding their desires, goals, and fears. The Quest for Life-Long Learning and Maintenance of Certification Physicians should be engaged in life-long learning. The most admired physicians are those who continually seek Inhibitors,research,lifescience,medical new knowledge and strive for constant improvement. The process of self-reflection is one that should be incorporated into every day, in which the physician examines critically what went Inhibitors,research,lifescience,medical well, what didn’t go well, and what is needed to do better next time. Maintenance of Certification should not be looked upon as a punishment or requirement but as part of a physician’s responsibility to their patients and society. However, there must be a collaborative effort among certifying boards, professional societies,

and academic medical centers to provide credit for engaging in life-long learning (synchronous Inhibitors,research,lifescience,medical and asynchronous with direct patient care) that is truly relevant to an individual physician’s practice. The Role of Societies and Academic Medical Centers All professional societies and academic medical Inhibitors,research,lifescience,medical centers recognize the importance of physician competence. Proper tools and resources must be provided so that all physicians remain competent in their chosen practice. Physicians must take it upon http://www.selleckchem.com/products/crenolanib-cp-868596.html themselves to demonstrate that they remain competent throughout their career. The medical profession has never been held accountable to this level before, and it is up to us Inhibitors,research,lifescience,medical to assure that we train the most highly competent physicians for the future. Licensing bodies and

professional societies must assure the public that they are receiving care from competent physicians. Attainment and continuous demonstration of competence are laudable and appropriate goals Cilengitide for our profession and patients. Funding Statement Funding/Support: The authors have no funding disclosures. Footnotes Conflict of Interest Disclosure: The authors have completed and submitted the Methodist DeBakey Cardiovascular Journal Conflict of Interest Statement and none were reported.
Introduction There are many benefits of early mobilization for adult patients in the ICU, including reduced length of ICU and hospital stays and, therefore, fewer days of detrimental bedrest; fewer ICU readmissions; decreased duration of mechanical ventilation; minimal adverse or unsafe events; and improved walking distance.1-14 In a study by Bailey et al.

This and other early (eg, refs 12-14) computational models of the

This and other early (eg, refs 12-14) computational models of the BOLD phenomenon are currently understood to be largely accurate, albeit incomplete with respect to the mechanisms contributing to functional mapping signals. Some of these initially overlooked mechanisms (eg, inflow effects) form the basis of the successful use of lower

field strengths, such as 1.5 T, for the acquisition of functional images in human brain. Nevertheless, increased understanding of the origin of fMRI signals (see ref 15 and references therein) Inhibitors,research,lifescience,medical have also reconfirmed original expectations that there are major advantages in going to very high magnetic fields, and these have largely been experimentally verified by a plethora of studies

conducted with kinase inhibitor Pazopanib animal models (eg, refs 1, 16-18). For example, in Inhibitors,research,lifescience,medical fMRI, the contrast-to-noise ratio (CNR) of deoxyhemoglobin-based BOLD mapping signals increases linearly in high-resolution imaging for gradient echo (GE)-based techniques, the predominant approach employed in contemporary fMRI experiments. (Contrast in fMRI is defined as the magnitude of the signal change induced by a stimulus or a task. Contrast-to Inhibitors,research,lifescience,medical noise ratio CNR is the ratio of the contrast to the signal fluctuations in the fMRI time series). When image resolution is high, the latter is dominated by the “thermal” noise present in each image of the time series. At low resolution, CNR for GE fMRI increases less than linearly with field magnitude since the temporal fluctuations of signals become dominated by physiological processes (rather than thermal noise) and display a dependence on signal amplitude, hence magnetic field magnitude. For spin echo (SE) BOLD fMRI, which provides more accurate functional Inhibitors,research,lifescience,medical localization,1,16-17 albeit only at high magnetic

inhibitor expert fields and with smaller signal changes1,9,20 CNR can exhibit more than a linear dependence on magnetic field magnitude because of suprallnear gains in fractional signal change induced by neuronal activity19-20 and a linear Inhibitors,research,lifescience,medical elevation in intrinsic AV-951 image signal-to-noise ratio (SNR).21 The gains in fractional signal change, however, tend to level off at fields above -9 to 10 Tesla,15 leaving the SNR gains as the only potential source of CNR improvements. More importantly, however, higher magnetic fields provide significantly better spatial fidelity in the deoxyhemoglobin-based functional mapping signals (eg, refs 1,16,17). fMRI relies on secondary metabolic and vascular responses invoked by alterations in neuronal activity. Therefore, its accuracy can be degraded by limitations imposed by these secondary responses. However, in a critical experiment performed in the cat visual cortex, it was demonstrated that blood flow increase induced by functional activation is regulated at the level of orientation columns.