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Biomedical subjects

M J Barbanoj

Publications and source records attributed to M J Barbanoj.

At least 19 recordsLinked to original sources
PubMed2006

Influence of individual differences in the Behavioral Inhibition System and stimulus content (fear versus blood-disgust) on affective startle reflex modulation.

Inconsistencies among affective startle reflex modulation studies may be due to differences in the startle potentiation produced by the specific content of the images used, to individual differences in sensitivity to negative stimuli, or to the interaction of both factors. To explore this interaction, 52 undergraduates obtaining extreme scores on a self-report measure of the Behavioral Inhibition System (BIS) participated in an affective startle reflex modulation paradigm. A significant interaction between BIS group (high versus low) and image content emerged from the MANOVA. Comparing startle magnitude between fear and pleasant images, low BIS participants did not seem to show startle potentiation, whereas high BIS participants did. Both groups displayed potentiated startle during blood-disgust images. The present results suggest the importance of considering personality variables and their interaction with image content in the affective startle modulation paradigm.

Adult↗
PubMed2006

Quantifying drug-drug interactions in pharmaco-EEG.

A drug interaction refers to an event in which the usual pharmacological effect of a drug is modified by other factors, most frequently additional drugs. When two drugs are administered simultaneously, or within a short time of each other, an interaction can occur that may increase or decrease the intended magnitude or duration of the effect of one or both drugs. Drugs may interact on a pharmaceutical, pharmacokinetic or pharmacodynamic basis. Pharmacodynamic interactions arise when the alteration of the effects occurs at the site of action. This is a wide field where not only interactions between different drugs are considered but also drug and metabolites (midazolam/alpha-hydroxy-midazolam), enantiomers (ketamine), as well as phenomena such as tolerance (nordiazepam) and sensitization (diazepam). Pharmacodynamic interactions can result in antagonism or synergism and can originate at a receptor level (antagonism, partial agonism, down-regulation, up-regulation), at an intraneuronal level (transduction, uptake), or at an interneuronal level (physiological pathways). Alternatively, psychotropic drug interactions assessed through quantitative pharmaco-EEG can be viewed according to the broad underlying objective of the study: safety-oriented (ketoprofen/theophylline, lorazepam/diphenhydramine, granisetron/haloperidol), strictly pharmacologically-oriented (benzodiazepine receptors), or broadly neuro-physiologically-oriented (diazepam/buspirone). Methodological issues are stressed, particularly drug plasma concentrations, dose-response relationships and time-course of effects (fluoxetine/buspirone), and unsolved questions are addressed (yohimbine/caffeine, hydroxizyne/alcohol).

Brain↗
PubMed2005

Effects of tobacco smoking on the kinetics of the pupillary light reflex: a comparison between smokers and non-smokers.

BACKGROUND: The time course of the pupillary light reflex (PLR) is determined by the successive activation of parasympathetic and sympathetic innervations of the iris, latency and amplitude reflecting parasympathetic activity and recovery time showing mainly sympathetic activity. OBJECTIVE: To determine the effects of tobacco cigarette smoking on the PLR in smokers after an abstinence period of at least 12 h. METHODS: Ten smokers (mean 15.7 cigarettes/day) and 10 non-smokers participated in a randomised, non-intervention controlled, cross-over study that included a parallel control group. Smokers underwent two sessions with a time interval between 3 and 8 days; two recordings were taken at each session, separated by 20 min: session 1, without smoking, and session 2, smoking 3 cigarettes within a 30-min period. Non-smokers underwent one session; two recordings were taken separated by 20 min. At each recording, in both groups, PLR was elicited with four light flashes of increasing luminance. RESULTS: The relationship between PLR parameters and light intensity was linear in each subject. The slope of the regression line for relative amplitude increase versus intensity was significantly flatter in abstinent smokers than in non-smokers (p=0.033); the slope returned significantly after smoking (p=0.043). No other significant effects were obtained. CONCLUSIONS: Kinetic parameters of PLR provide a sensitive pharmacological test to detect cholinergic neurotransmission manipulation effects, as they seem to detect changes in moderate smokers after 12 h of abstinence, and their reversal on return to smoking. These results suggest an enhancement in the suppression of the parasympathetic oculomotor reflex arc rather than a facilitation of the sympathetic drive to the iris.

Adult↗
PubMed2005

Access of HTB, main metabolite of triflusal, to cerebrospinal fluid in healthy volunteers.

OBJECTIVE: Triflusal has been shown to exert neuroprotective effects by downregulating molecules considered responsible for the development of Alzheimer's disease (AD). The aim of this study was to develop a population pharmacokinetic model to characterize plasma and cerebrospinal fluid (CSF) pharmacokinetics of the main active metabolite of triflusal-HTB (2-hydroxy-4-trifluoro-methylbenzoic acid)-in healthy volunteers. METHODS: Data from two studies were combined. Study A: subjects received single oral doses of triflusal 900 mg. Triflusal and HTB plasma concentrations were extensively measured. Study B: triflusal 600 mg once daily was administered orally for 14 days. HTB plasma and CSF concentrations were determined in healthy volunteers. Population pharmacokinetic modeling was performed using NONMEM. RESULTS: A one-compartmental model with rapid first-order absorption for triflusal and first-order formation of HTB best described plasma concentrations. Triflusal elimination rate constant was 50 times faster than that estimated for the metabolite. CSF concentrations of HTB ranged between 0.011 microg/ml and 0.341 microg/ml. A CSF-plasma partition coefficient of 0.002 and a k(e0) value of 0.059 h(-1) were estimated by means of population modeling. CONCLUSION: In the present study in healthy volunteers, HTB penetrated into the CSF in a range of concentrations experimentally proven to have protective effects in AD. These concentrations suggest that triflusal could be used in the treatment of central nervous system diseases in doses similar to those used in cardiovascular diseases. Access to the CSF compartment was characterized by a slow equilibrium rate constant and a low CSF-plasma partition coefficient.

Adult↗
PubMed2004

Pharmacokinetics of a new Autogel formulation of the somatostatin analogue lanreotide after a single subcutaneous dose in healthy volunteers.

The pharmacokinetics/tolerability of lanreotide Autogel have been evaluated. Healthy volunteers (n = 24) first received immediate-release lanreotide as a single subcutaneous (s.c.) injection. After two days, 40 or 60 mg lanreotide Autogel was injected subcutaneously. Blood was sampled at various intervals for 56 days. Systemic/local adverse events and changes in biological profile/vital signs were recorded. Lanreotide Autogel produced a prolonged-release pharmacokinetic profile: mean area under the serum concentration-time curve from time 0 to infinity (AUC) was 53.73 +/- 8.99 and 79.48 +/- 13.06 ng mL(-1) day for 40 and 60 mg, respectively, mean peak serum concentration (C(max)) was 4.38 +/- 2.91 and 5.71 +/- 3.52 ng mL(-1), respectively, median time to reach C (minimum-maximum) was 0.50 (0.083-18.0) and 0.38 (0.083-9.01) days, respectively, mean apparent elimination half-life was 21.63 +/- 9.42 and 22.01 +/- 9.87 days, respectively, and relative bioavailability was 0.93 +/- 0.12 and 0.82 +/- 0.15, respectively. Thus, lanreotide Autogel exhibited linear pharmacokinetics for the doses studied. Pharmacokinetic profiles were similar in both genders, apart from statistically significant differences in C(max) and C(max)/AUC. The Autogel formulation of lanreotide was well tolerated, with systemic adverse events being mild/moderate. Erythema and a painless subcutaneous induration were the most common local adverse events. Lanreotide Autogel provided a prolonged dosing interval and good tolerability for treating acromegaly and carcinoid syndrome.

Adolescent↗
PubMed2003

Transcranial magnetic stimulation for the treatment of obsessive-compulsive disorder.

BACKGROUND: Transcranial magnetic stimulation (TMS) was introduced as a neurophysiological technique in 1985 when Anthony Barker and his team developed a compact machine that permitted non-invasive stimulation of the cerebral cortex (Barker 1985). Since its introduction, TMS has been used to evaluate the motor system, to study the function of several cerebral regions, and for the pathophysiology of several neuropsychiatric illnesses. In addition, it has been suggested that TMS might have therapeutic potential. Some controlled studies have evaluated the effects of repetitive TMS (rTMS) in patients with obsessive-compulsive disorder (OCD). Greenberg (Greenberg 1997) observed that a single session of right prefrontal cortex stimulation produced a significant decrease in compulsive urges in OCD patients lasting over eight hours. Other studies have reported transitory improvements in mood but there are no observations for changes in anxiety or obsessions. OBJECTIVES: To develop a systematic review on the clinical efficacy and safety of transcranial magnetic stimulation from randomised controlled trials in the treatment of obsessive-compulsive disorder. SEARCH STRATEGY: An electronic search was performed including the Cochrane Collaboration Depression, Anxiety and Neurosis Review Group trials register (last searched June, 2002), the Cochrane Controlled Trials Register (Issue 2, 2002), MEDLINE (1966-2002), EMBASE (1974-2002), PsycLIT (1980-2002), and bibliographies from reviewed articles. SELECTION CRITERIA: Randomised controlled trials assessing the therapeutic efficacy and safety of transcranial magnetic stimulation for obsessive-compulsive disorder. DATA COLLECTION AND ANALYSIS: All reviewers independently extracted the information and verified it by cross-checking. Disagreements were resolved through discussion. MAIN RESULTS: Three trials were included in the review and only two contained data in a suitable form for quantitative analysis. It was not possible to pool any results for a meta-analysis. No difference was seen between rTMS and sham TMS using the Yale-Brown Obsessive-Compulsive Scale or the Hamilton Depression Rating Scale for all time periods analysed. REVIEWER'S CONCLUSIONS: There are currently insufficient data from randomised controlled trials to draw any conclusions about the efficacy of transcranial magnetic stimulation in the treatment of obsessive-compulsive disorder.

Humans↗
PubMed2003

A study comparing the inhibitory effects of single and repeated oral doses of ebastine and fexofenadine against histamine-induced skin reactivity.

OBJECTIVE: The aim of this double-blind, randomized, crossover, placebo-controlled clinical trial was to compare the inhibition of the histamine-induced skin reaction induced by ebastine 20 mg with respect to that induced by fexofenadine 120 mg or placebo. METHODS: Eighteen volunteers (10 males, 8 females) received the three treatments once daily for 5 days, with a mean 7-day washout period between treatments. Intradermal tests, using 0.05 ml from a solution containing 100 microg/ml of histamine, were performed at baseline and at 1, 1.5, 2, 3, 10 and 24 h after a single dose and repeated 5-day dose, and in addition after 34, 48, 58 and 72 h after repeated 5-day dose. RESULTS: After 24 h of acute administration, ebastine 20 mg was significantly more effective than fexofenadine 120 mg in reducing the wheal and flare induced by histamine challenge (p<0.001). Although fexofenadine 120 mg had the shortest onset of action (1.5 vs. 3 h in ebastine 20 mg), the duration of its antihistamine effect was the shortest (24 vs. 58 h in ebastine 20 mg) and wheal reduction after 24 h was not significantly different from placebo. The overall effect after single and repeated 5-day dose, expressed as the AUC of reduction of wheal and flare area (%/h), showed the following order of magnitude: ebastine 20 mg>fexofenadine 120 mg>placebo. No significant differences in the incidence of adverse events were found between the three treatments. CONCLUSIONS: The present results clearly show a superior and long-acting effect of ebastine 20 mg compared with fexofenadine 120 mg on the skin response to histamine 24 h after dosing.

Administration, Oral↗
PubMed2002

Transcranial magnetic stimulation for treating depression.

BACKGROUND: Transcranial magnetic stimulation can either excite or inhibit cortical areas of the brain, depending on whether the speed of the repetitive stimulation is applied at high or low frequencies. It has been used for physiological studies and it has also been proposed as a treatment for depression. OBJECTIVES: To assess the clinical efficacy and safety of transcranial magnetic stimulation for treating depression. SEARCH STRATEGY: An electronic search was performed including the Cochrane Collaboration Depression, Neurosis and Anxiety Review Group trials register (last searched June, 2001), the Cochrane Controlled Trials Register (Issue 2, 2001), MEDLINE (1966-2001), EMBASE (1974-2001), PsycLIT (1980-2001), and bibliographies from reviewed articles. Unpublished data and grey literature were searched through personal communications with researchers. SELECTION CRITERIA: Randomised controlled trials assessing the therapeutic efficacy and safety of transcranial magnetic stimulation for depression. DATA COLLECTION AND ANALYSIS: All reviewers independently extracted the information and verified it by cross-checking. Disagreements were resolved through discussion. Continuous data: When similar studies were grouped, the overall standardised mean difference was calculated under a fixed effect model weighted by the inverse variance method with 95% confidence intervals. (In the presence of statistical heterogeneity, a random effects model was to be used.) MAIN RESULTS: Sixteen trials were included in the review and fourteen contained data in a suitable form for quantitative analysis. Most comparisons did not show differences between rTMS and other interventions. No difference was seen between rTMS and sham TMS using the Beck Depression Inventory or the Hamilton Depression Rating Scale, except for one time period (after two weeks of treatment) for left dorsolateral prefrontal cortex and high frequency; and also for right dorsolateral prefrontal cortex and low frequency, both in favour of rTMS and both using the Hamilton scale. Comparison of rTMS (left dorsolateral prefrontal cortex and high frequency) with electroconvulsive therapy showed no difference except for psychotic patients after two weeks treatment, using the Hamilton scale, which indicated that electroconvulsive therapy was more effective than rTMS. REVIEWER'S CONCLUSIONS: The information in this review suggests that there is no strong evidence for benefit from using transcranial magnetic stimulation to treat depression, although the small sample sizes do not exclude the possibility of benefit.

Depression↗
PubMed2002

Pharmaco-electroencephalography and pharmacokinetic/pharmacodynamic modeling in basic research: focus on human pharmacology.

Pharmacokinetic/pharmacodynamic modeling, together with electroencephalography (EEG), have been successfully applied to obtain in vivo pharmacological information of different drugs acting on the central nervous system (CNS) in humans and of the systems with which the drugs interact. Almost all types of variables used to assess the activity of drugs in the human CNS have already been applied in pharmacokinetic/pharmacodynamic research. However, compared with more traditional approaches to quantify the pharmacodynamics of neuropsychotropic drugs, the EEG method has the advantage of being objective, sensitive, continuous and reproducible. The present review focuses mostly on benzodiazepine pharmacology. A selection of some basic aspects that can be covered using pharmaco-EEG and pharmacokinetic/pharmacodynamic modeling from in vivo studies performed in humans in pharmacological research will be introduced: i) determination of the pharmacological characteristics of a compound; ii) comparison of potencies among drugs; iii) comparison of efficacy among drugs; iv) tolerance development; v) metabolite role; vi) enantiomers; vii) drug-drug interactions; viii) circadian rhythms; ix) factors affecting the observed effect; and x) the gain of physiopathological information about the systems with which drugs interact. Looking at the quantity and quality of the results obtained for the benzodiazepines, pharmacokinetic/pharmacodynamic modeling using EEG measures appears to be an ideal tool, and is potentially useful for other drugs acting on the CNS.

Benzodiazepines↗
PubMed2002

Uses of pharmaco-EEG and pharmacokinetic-pharmacodynamic modeling in the clinical scenario.

In order to place pharmaco-EEG within the clinical context, the distinction between biomarkers, surrogate endpoints, clinical endpoints and clinical outcomes is introduced. State-of-the-art applications of pharmaco-EEG, together with pharmacokinetic-pharmacodynamic modeling in everyday clinical practice in anesthesiology (semilinear canonical correlation), psychiatry (discrimination between responders and nonresponders to pharmacological treatment using the test dose), neurology (antiepileptic field) and neurophysiology (first-order Markov model of sleep stage transitions) are discussed. The combination of both procedures, although successfully used during some drug development programs (opioids or benzodiazepines), is not widely applied in the clinical scenario where the central nervous system (CNS) is concerned. Much work is still need to develop fully the potentials that pharmaco-EEG together with pharmacokinetic-pharmacodynamic modeling could bring to therapeutics in neuroscience.

Biomarkers↗
PubMed2002

Proof of safety of drugs: focus on vigilance.

It is well accepted that all new compounds, before administration to patients, should undergo safety evaluations in healthy subjects, including central nervous system (CNS) toxicity and as such the assessment of vigilance effects a relevant hallmark. The original concept of vigilance as a phenomenon observed only under conditions of monotony and signal regularity is increasingly falling into disfavor, embracing at present a much broader spectrum of behavior. Currently, vigilance may be regarded as a "readiness to adopt the appropriate behavior in a given situation, which thus finds outward expression through the quality and quantity of the behavior occurring in response to a given (internal or external) stimulus situation". The assumption that vigilance is a multifactorial phenomenon and not merely EEG data should be taken into account in order to study it accurately. Specifically, in drug research, apart from subjective reports and psychomotor performance tests, neurophysiological evaluations are regularly used such as Multiple Sleep Latency Test, Vigilance Epoch Classification or Parameters within a continuous scale. Although with limitations, temporal patterns of changes in activity of different frequency bands, indexes as the alpha slow-wave or the alpha anteriorization, computed from the EEG quantification, yielded different definitions of the intermediate states of the transition from wakefulness to sleep through the so-called subvigil stages. Spatial patterns are less documented. The recently proposed mathematical models to explain and predict variations in alertness are presented. Examples of the effects of different classes of drugs with the methods reported and its theoretical and practical relevance to vigilance research are introduced.

Arousal↗
PubMed2002

Basics of PK-PD using QEEG: acute/repetitive administration, interactions. Focus on anxiolytics with different neurochemical mechanisms as examples.

Utilizing computer-assisted quantitative analysis of the electroencephalogram (EEG) in combination with certain statistical procedures and under specific design conditions, it is possible to objectively evaluate the functional bioavailability of psychotropic substances in the target organ: the human brain. Specifically, one may determine whether a drug is active in the central nervous system (CNS) compared with placebo in humans, the dose effect (including nonmonotonic drug effects along the continuum range of concentrations) and the time effect (including time-dependent pharmacodynamic phenomena as tolerance and sensitization), as well as its activity in relation to the formulation and route of application. Methodological aspects are introduced, discussing the usefulness of evaluating different treatments, doses, time points, states, target variables, electrodes and even different groups. Several issues are raised in relation to acute vs. repetitive administration, particularly those dealing with statistical comparisons when making conclusions about acute, repetitive or superimposed effects, and in relation to human psychotropic interactions, such as mechanistic drug-drug interaction descriptions, drug metabolites and enantiomers, as well as the importance of acquiring drug plasma concentrations, elapse of time and topographic distributions to accurately identify its occurrence. PK-PD modeling is introduced as a tool to enlarge the scope of inferences that can be derived when using pharmaco-EEG. The examples presented in order to develop the arguments are mainly focused on anxiolytic compounds belonging to the different neurochemical groups, benzodiazepines and azaspirones. Questions that have yet to been resolved are also addressed.

Anti-Anxiety Agents↗
PubMed2001

Psychometric assessment of the Hallucinogen Rating Scale.

Reliability and convergent-discriminant validity of a Spanish version of the Hallucinogen Rating Scale (HRS) were assessed in two differentiated populations of hallucinogen users involving the retrospective assessment of drug effects. In Study 1 (immediate assessment), 75 European users of the South American hallucinogenic drink ayahuasca answered the HRS 4 h after drug intake in their habitual setting. In Study 2 (delayed assessment), 56 adult polydrug users answered the HRS and a short form of the Addiction Research Center Inventory (ARCI) recalling the effects they experienced when they last took a hallucinogen, in order to test the convergent-discriminant validity of HRS with the scales of the standard questionnaire used in most studies involving psychoactive drugs. The HRS scales showed increases after both the immediate and delayed retrospective assessment of drug effects. Reliability data indicated that four of the six scales show an acceptable level of internal consistency. Significant but limited correlations were found between the Perception and Somaesthesia scales and the ARCI LSD scale, pointing out the questionnaire's construct validity. Thus, the HRS was sensitive to hallucinogenic drug effects other than those elicited by intravenous N,N-dimethyltryptamine (DMT), for which it was originally designed, and showed reasonable reliability and convergent validity. Results suggest its usefulness in the evaluation of subjective effects elicited by psychoactive drugs with hallucinogenic properties, and constitute a preliminary approach to the effects of ayahuasca in European subjects.

Adolescent↗
PubMed2001

Subjective effects and tolerability of the South American psychoactive beverage Ayahuasca in healthy volunteers.

RATIONALE: Ayahuasca is a South American psychoactive beverage that contains the naturally occurring psychedelic agent N,N-dimethyltryptamine (DMT). This "tea" has been used for centuries in religious and medicinal contexts in the rain forest areas of South America and is presently gaining the attention of psychedelic users in North America and Europe. OBJECTIVES: In the present study, the psychological effects and tolerability of ayvahuasca were assessed. METHODS: Three increasing doses of encapsulated freeze-dried ayahuasca (0.5, 0.75, and 1.0 mg DMT/kg body weight) were administered to six healthy male volunteers with prior experience in the use of this tea, in a single-blind crossover placebo-controlled clinical trial. RESULTS: Ayahuasca produced significant dose-dependent increases in five of the six subscales of the Hallucinogen Rating Scale, in the LSD, MBG, and A scales of the Addiction Research Center Inventory, and in the "liking", "good effects" and "high" visual analogue scales. Psychological effects were first noted after 30-60 min, peaked between 60-120 min, and were resolved by 240 min. The tea was well tolerated from a cardiovascular point of view, with a trend toward increase for systolic blood pressure. Modified physical sensations and nausea were the most frequently reported somatic-dysphoric effects. The overall experience was regarded as pleasant and satisfactory by five of the six volunteers, while one volunteer experienced an intensely dysphoric reaction with transient disorientation and anxiety at the medium dose and voluntarily withdrew from the study. CONCLUSIONS: Ayahuasca can be described as inducing changes in the perceptual, affective, cognitive, and somatic spheres, with a combination of stimulatory and visual psychoactive effects of longer duration and milder intensity than those previously reported for intravenously administered DMT.

Adult↗
PubMed2001

Differential effects of alprazolam on the baseline and fear-potentiated startle reflex in humans: a dose-response study.

RATIONALE: The "fear-potentiated startle" paradigm has been extensively used in animal studies, and more recently in human experimental psychopharmacology to evaluate the effects of anxiogenic and anxiety-relieving drugs. Previous human studies have shown that both the baseline and the fear-potentiated responses can be inhibited by anxiety-relieving drugs, suggesting drug activity on two different emotional states, the former reflecting a resting condition and the latter more akin to pathological anxiety. OBJECTIVES: To examine to which extent the reductions induced by a benzodiazepine on the basic and the fear-potentiated startle responses are of equal intensity, and whether or not the drug shows a predominant, i.e., selective, effect on either. METHODS: The effects of three increasing doses of the benzodiazepine alprazolam (0.25, 0.5, and 1.0 mg) were assessed on the human baseline and fear-potentiated startle responses. Twelve healthy volunteers attended the laboratory on four experimental days and received either alprazolam or placebo according to a double-blind crossover balanced design. Startle recordings were undertaken 2 h after drug intake. Fear potentiation was implemented by means of an electric-shock-anticipation experimental procedure. Additionally, subjective self-reports of sedation and anxiety and psychomotor performance were obtained at 2 and 3 h, respectively, after drug administration. RESULTS: Alprazolam dose-dependently impaired psychomotor performance and produced increases in subjective anxiolytic activity and sedation, although the latter did not reach statistical significance. Additionally, the drug reduced the magnitude of the startle response both in the absence and in the presence of a threat-related cue, although a differentially greater inhibitory effect was seen on the fear-potentiated response as the dose increased. CONCLUSIONS: Alprazolam showed a greater inhibitory effect on the fear-potentiated startle than on the baseline reflex, suggesting a more selective action of the drug on those structures mediating potentiation of the behavioral response by anxiety.

Acoustic Stimulation↗
PubMed2001

Low-resolution brain electromagnetic tomography revealed simultaneously active frontal and parietal sleep spindle sources in the human cortex.

Analyses of scalp-recorded sleep spindles have demonstrated topographically distinct slow and fast spindle waves. In the present paper, the electrical activity in the brain corresponding to different types of sleep spindles was estimated by means of low-resolution electromagnetic tomography. In its new implementation, this method is based on realistic head geometry and solution space is restricted to the cortical gray matter and hippocampus. In multichannel all-night electroencephalographic recordings, 10-20 artifact-free 1.25-s epochs with frontally, parietally and approximately equally distributed spindles were marked visually in 10 normal healthy subjects aged 20-35years. As a control condition, artifact-free non-spindle epochs 1-3s before or after the corresponding spindle episodes were marked. Low-resolution electromagnetic tomography demonstrated, independent of the scalp distribution, a distributed spindle source in the prefrontal cortex (Brodmann areas 9 and 10), oscillating with a frequency below 13Hz, and in the precuneus (Brodmann area 7), oscillating with a frequency above 13Hz. In extremely rare cases only the prefrontal or the parietal source was active. Brodmann areas 9 and 10 have principal connections to the dorsomedial thalamic nucleus; Brodmann area 7 is connected to the lateroposterior, laterodorsal and rostral intralaminar centrolateral thalamic nuclei. Thus, the localized cortical brain regions are directly connected with adjacent parts of the dorsal thalamus, where sleep spindles are generated. The results demonstrated simultaneously active cortical spindle sources which differed in frequency by approximately 2Hz and were located in brain regions known to be critically involved in the processing of sensory input, which is in line with the assumed functional role of sleep spindles.

Adult↗