A. M. L. Coenen

Radboud University | RU · Donders Institute for Brain, Cognition, and Behaviour

Sleep is a brain state characterised by a low vigilance level and diminished consciousness. Reaction to and processing of external stimuli is attenuated in sleep. During sleep, the reticular thalamic nucleus reduces the flow of sensory activity to the cerebral cortex through inhibition of the thalamus. This sensory gating process facilitates sleep....

The history of electroencephalography begins around 1850 with a supposition of Emil du Bois-Reymond concerning the transfer of information by electric currents over the nerve to the effector. Luigi Galvani in Bologna showed with his frog legs experiments 1786 indeed the existence of animal electricity. Richard Caton in Liverpool placed in 1875 as t...

Dear Reader! Today marked the 299th day of the war for the independence of Ukraine. Besides the Armed Forces of Ukraine, the frontline of our battle against the aggressor is being held by healthcare professionals whose selfless work saves lives and the health of patients and ensures the existence of Ukraine. From now on, along with experimental and...

Sleep is a state of the brain characterized by a low level of vigilance and diminished consciousness. The reaction to external stimuli and the processing of stimuli are attenuated in sleep. During sleep, the reticular thalamic nucleus inhibits at the thalamus the flow of sensory activity from the senses to the cerebral cortex. After arrival at the...

Despite an elevated recovery need, research indicates that athletes often exhibit relatively poor sleep. Timing and consolidation of sleep is driven by the circadian system, which requires periodic light-dark exposure for stable entrainment to the 24-hour day, but is often disturbed due to underexposure to light in the morning (e.g., low-level indo...

Performance capacity in athletes depends on the ability to recover from past exercise. While evidence suggests that athletic performance decreases following (partial) sleep deprivation and increases following sleep extension, it is unclear to which extent natural variation in sleep impacts performance. Sleep quantity and, for the first time, sleep...

Objectives: Sleep is essential for recovery and performance in elite athletes. While it is generally assumed that exercise benefits sleep, high training load may jeopardize sleep and hence limit adequate recovery. To examine this, the current study assessed objective sleep quantity and sleep stage distributions in elite athletes and calculated the...

Sleep is essential for recovery and performance in elite athletes. While actigraphy-based studies revealed suboptimal sleep in athletes, information on their subjective experience of sleep is scarce. Relatively unexplored is also the extent to which athletes’ sleep is adversely affected by environmental conditions and daytime behaviours, that is sl...

Each generation of students and professors of the Medical Faculty of Lviv University, now known as Danylo Halytsky Lviv National Medical University, makes a considerable contribution to the development of world science through dedicated service to the ideals of truth, education, reputable and responsible performance of their professional functions...

Introduction The purpose of this preliminary clinical trial was to investigate whether acupuncture has a positive influence on sleep and symptomatology in patients with schizophrenia or depression. Methods A randomized controlled trial was conducted. One hundred participants were recruited: 40 outpatients with schizophrenia, 40 with depression, and...

The relationships between frontal, temporal, and occipital zones of cortex of both hemispheres and paleocerebellar cortex in Wistar and WAG/Rij rats were investigated with an application of multiple linear regression analyses. Taking into consideration the dependence of epileptiform manifestations on sleep-wakefulness cycle, passive wakefulness sta...

Background: In patients with depression, as well as in patients with schizophrenia, both mood and working memory performance are often impaired. Both issues can only be addressed and improved with medication to some extent. Objective: This study investigates the mood and the working memory performance in patients with depression or schizophrenia...

Sleep problems and substance use are strongly linked. Sleep problems play a role in the etiology of substance use, but also may be a result of it. After detoxification, sleep problems may worsen leading to relapse. Nowadays, most substance dependence treatment programs aim at recovery rather than total abstinence, and in that view health-related qu...

procedure to induce chronic epilepsy. The aim of this study was to evaluate the possible effects of electrical stimulation (ES) of paleocerebellar cortex on anxiety and depressive-like behavior in a PTZ kindled epilepsy model. Kindling was induced via pentylenetetrazol (PTZ) (25.0 mg/kg IP daily) during three weeks. Locomotion in open field, elevat...

While previous studies on the MMPI-2 in patients with schizophrenia and depression have used mixed samples of both early stage and chronic psychiatric patients. Here, it is investigated whether chronicity itself might have a differential effect on the MMPI-2 profiles of these patients and whether demoralization ‘associated with long-term illness’ a...

Adolf Beck, born in 1863 at Cracow (Poland), joined the Department of Physiology of the Jagiellonian University in 1880 to work directly under the supervision of the prominent physiology professor, Napoleon Cybulski. Following his suggestion, Beck started experimental studies on the electrical brain activity of animals, especially in response to se...

Anxiety and depression are component of interictal behavioral deteriorations that occur as a consequence of kindling, a procedure to induce chronic epilepsy. The aim of this study was to evaluate the possible effects of electrical stimulation (ES) of paleocerebellar cortex on anxiety and depressive-like behavior in a PTZ kindled epilepsy model. Kin...

Adolf Beck, born in 1863 in Kraków (Poland), joined the Department of Physiology of the Jagiellonian University in 1889, to work directly under the prominent professor in physiology Napoleon Cybulski. Following his suggestion, Beck started studies on the electrical brain activity of animals. He recorded negative electrical potentials in several bra...

Adolf Beck, born in 1863 in Kraków (Poland), joined the department of Physiology of the Jagiel-lonian University in 1889, to work directly under the prominent professor in physiology napoleon cybulski. Following his suggestion, Beck started studies on the electrical brain activity of animals. he recorded negative electrical potentials in several br...

Professor Adolf Beck (1863-1942), the founder of Physiology Department of the Lviv National Medical University who stood at the cradle of studies of the manifestation of the electrical brain activity, fought political discrimination and racism (anti-Semitism) on his way to becoming one of the XX century’s leading but still unknowing in XXI century...

The interest of psychiatric patients for complementary medicine, such as acupuncture, is stable, but effect studies in psychiatry remain scarce. In this pilot study, the effects of 3 months of acupuncture treatment on sleep were evaluated and compared between a group of patients with schizophrenia (n = 16) and a group with depression (n = 16). Heal...

Relationship between psychometric intelligence measured with Raven's Advanced Progressive Matrices (RAPM) and event-related potentials (ERP) was examined using 3-stimulus oddball task. Subjects who had scored higher on RAPM exhibited larger amplitude of P3a component. Additional analysis using the Standardized Low Resolution Electromagnetic Tomogra...

Background The aim was to investigate the subjective experience of parasomnias and other nocturnal behaviors in depression and schizophrenia. Materials and methods Using the Munich Parasomnia Screening (MUPS), 21 parasomnias and other nocturnal behaviors were assessed in 85 participants; 27 were patients with depression, 29 were patients with schi...

Purpose: The occurrence of spike-wave discharges (SWDs) in WAG/Rij rats is modulated by the circadian timing system and is shaped by the presence of a light-dark cycle, motor activity, and state of vigilance. Here it is investigated whether the response to a phase shift is different between the SWDs and general motor activity rhythm. The process o...

Stunning effectiveness of male and female broiler chickens was analyzed in response to different waveforms at 3 constant voltage levels. In total, 180 male and female broiler chickens were stunned using a sine wave alternating current (AC) of 50 Hz, rectangular AC of 70 Hz, and pulsed direct current (DC) of 70 Hz (duty-cycle 1:1) with a constant vo...

The aim of the present study was to define the scalp topography of the two subcomponents of the P3 component of the auditory evoked potential elicited in a three-stimulus oddball paradigm and to identify their cortical generators using the standardized low resolution electromagnetic tomography (sLORETA). Subjects were presented with a random sequen...

We investigated the role of two cytokines, IL-1β and TNF-α, in the development of absence seizures using a genetic model of absence epilepsy in WAG/Rij rats. We administered these cytokines to animals systemically and measured the number of spike-wave discharges (SWDs) in the EEG. We also coadministered IL-1β with the GABA reuptake inhibitor tiagab...

Administration of benzyl penicillin (300,00000 IU/kg, i.p.) in free moving Wistar rats causes the precipitation of spikes and generalized ictal potentials with a life-span of epileptic activity up to 6 hours. Periodic electrical stimulation (ES) of the paleocerebellum (100 Hz, 1 ms, 100-180 μA duration of trial 1 s, inter-stimulus interval 3.5-4.0...

Stunning efficiency of male and female broiler chickens was analysed in response to the two-phase Simmons step-up stunner. In Phase I, a pulsed DC of 550 Hz is applied in a shallow waterbath. This is immediately followed by Phase II, consisting of a metal plate with sine wave AC of 50 Hz. 120 male and female broiler chickens were randomly allocated...

Hypnotic drugs are intended to induce sedation and promote sleep. As a result, they have deteriorating effects on cognitive performance following intake. Most hypnotics are benzodiazepine receptor agonists which can have effects on memory in addition to their sedative effects. Other sedating drugs, such as histamine H1 antagonists or melatonin agon...

The shape of evoked potentials is influenced by the level of vigilance, varying with sleep-wake states. In this paper the shape of auditory evoked potentials is modelled by taking two factors, both modulating the underlying neuronal substrate, into account: 'sensory gating' and 'neuronal firing mode'. Under low levels of vigilance sensory gating re...

Adolf Beck (1863-1942) can be regarded as the co-founder of electroencephalography. His studies on the cerebral cortex of animals have facilitated the introduction of the electroencephalogram (EEG) as a main tool for studying the brain. The localization of senses on the cortex with evoked potentials and the description of the desynchronization of t...

The relationships between subjective estimation of emotional state and synchronization patterns in cortical emotional systems were investigated. The emotional state varied between groups using diazepam, buspirone, and placebo. The University of Wales Institute of Science and Technology Mood Adjective Checklist was used for the assessment of emotion...

The rhythms of spontaneously occurring seizures (spike-wave discharges, SWD) and motor activity, as well as the relationship between SWD and sleep-wake states were investigated in the WAG/Rij rat model of absence epilepsy. In order to establish whether SWD are controlled by external (Zeitgebers) or by endogenous factors such as circadian influences...

The question whether decapitation is a humane method of euthanasia in awake animals is being debated. To gather arguments in this debate, obsolete rats were decapitated while recording the EEG, both of awake rats and of anesthetized rats. Following decapitation a fast and global loss of power of the EEG was observed; the power in the 13-100 Hz freq...

The relationships between frontal, temporal, and occipital zones of cortex of both hemispheres and paleocerebellar cortex in Wistar and WAG/Rij rats were investigated with an application of multiple linear regression analyses. Taking into consideration the dependence of epileptiform manifestations on sleep-wakefulness cycle, passive wakefulness sta...

Thus far, most hypotheses on the evolutionary origin of sleep only addressed the probable origin of its main states, REM and NREM. Our article presents the origin of the whole continuum of mammalian vigilance states including waking, sleep and hibernation and the causes of the alternation NREM-REM in a sleeping episode. We propose: (1) the active s...

Stunning efficiency of broilers after electrical waterbath stunning with an alternating current was assessed using electroencephalograms (EEG) and physical reflexes. Four hundred eighty-nine broilers (246 males and 243 females) were stunned in an electrical waterbath with a rectangular alternating stunning current of 60, 80, 100, 120, and 150 mA an...

Stunning efficiency of a pulsed direct current was assessed regarding the effect on the electroencephalogram (EEG) and physical reflexes. Four hundred sixty-seven broilers (males and females) were stunned in an electrified waterbath with 60, 80, 100, 120, and 150 mA at frequencies of 70, 100, 200, 400, 800, and 1,500 Hz. Stunning time was 10 s. The...

The study determines the associations between self-report of ongoing emotional state and EEG patterns. A group of 31 hos-pitalized patients were enrolled with three types of diagnosis: major depressive disorder, manic episode of bipolar affective disorder, and nonaffective patients. The Thayer ADACL checklist, which yields two subjective dimensions...

During sleep, consciousness is reduced, associated with a diminished connection of the brain to the environment. This is due to the blocking of the thalamocortical pathway by inhibitory mechanisms. This "thalamic gating" during sleep, however, is not complete, but partial. The stream of information is considerably reduced, but the brain is not full...

The muscarinic agonist pilocarpine has been shown to increase the duration and total number of episodes presenting theta rhythm-simultaneously in hippocampus and cortex-in rats during the waking states. Theta waves are suggested to be involved in the flow of information between hippocampus and cortex during memory processes. This work investigates...

Since the first reports of neurofeedback treatment in Attention Deficit Hyperactivity Disorder (ADHD) in 1976, many studies have investigated the effects of neurofeedback on different symptoms of ADHD such as inattention, impulsivity and hyperactivity. This technique is also used by many practitioners, but the question as to the evidence-based leve...

Cortical spreading depression (SD) is thought to underlie the migraine aura but the mechanisms of triggering SD in the human cortex remain unknown. Because growing evidence points to a key role of brainstem circuits in initiating migraine attacks, the present study examined whether recurrent episodes of brainstem activation in rats could induce cor...

Recent findings have challenged the traditional view that the thalamus is the primary driving source of generalized spike-wave discharges (SWDs) characteristic for absence seizures, and indicate a leading role for the cortex instead. In light of this we investigated the effects of thalamic lesions on SWDs and sleep spindles in the WAG/Rij rat, a ge...

A large, negative wave which reaches its peak amplitude around 150 ms after stimulus onset, can be found in the Auditory Evoked Potential (AEP) recorded from the lateral amygdala in the rat. Previous studies in our laboratory have repeatedly shown that this N150 component increases during various aversive conditioning protocols and that this increa...

This study examined the welfare implications of euthanizing broilers with 3 gas mixtures relevant to the commercial application of controlled atmosphere stunning (CAS). Birds were implanted/equipped with electrodes to measure brain activity (electroencephalogram, EEG) and heart rate. These signals were recorded using a purpose-built telemetry-loggi...

This study tested whether a general increase in emotional arousal is a sufficient determinant for the evocation of the N150, a negative wave in amygdalar Auditory Evoked Potentials (AEPs). Rats received one of three conditioning protocols: either conditioned stimulus (CS) presentations alone (Control) CS-shock pairings (Paired) or unpaired presenta...

The discovery, development, and use of genetic rodent models of absence epilepsy have led to a new theory about the origin of absence seizures. A focal zone has been identified in the peri-oral region of the somatosensory cortex in WAG/Rij and GAERS – the two most commonly used models – from which the seizure quickly spreads over the cortex and to...

Stunning efficiency was established by measuring the electroencephalogram (EEG) of chickens just before and just after electrical waterbath stunning. The chicken EEG clamp (CHEC) was used to record the pre-stun EEG in 14 wake broilers and with Fast Fourier Transformations (FFTs) the total electrical power of this raw base-line EEG was obtained. A g...

The aim of this study was the comparison of basic characteristics of the P3 subcomponents elicited in passive and active versions of the auditory oddball paradigm. A 3-stimulus oddball paradigm was employed in which subjects were presented with random sequence of tones while they performed a discrimination task in visual modality with no response t...

Co-variation between subjectively estimated mood/activation and EEG characteristics, based on spectral power parameters, was investigated. Subjective estimation of mood was made by using Thayer's Activation-Deactivation Adjective Checklist, which yielded two dimensions: Energy-Tiredness (with Energy pole having positive valence connotation) and Ten...

The hypothesis was tested whether the amygdalar N150 of rats, a slow, negative component in the event-related potential from the lateral amygdala, is sensitive to a state of anxious anticipation. A conditioning procedure was applied in which a series of six auditory stimuli was followed by a shock when presented alone, but not when the auditory sti...

There is agreement that P300 is not a unitary brain potential but represents the summation of activity from various widely distributed areas in the brain. The distinction can be made between two subcomponents obtained within P300 time window, namely P3a and P3b. There is evidence that these components differ in their scalp topography, latency and r...

Controlled atmosphere (gas) stunning (CAS) has the potential to improve the welfare of poultry at slaughter but there is a lack of consensus about which gas mixtures are most humane. The aim of this study was to evaluate the welfare consequences of different gas stunning approaches. Individual broilers were exposed to gas mixtures capable of induci...

It has been suggested that theta rhythm gates the flow of information between the hippocampus and cortex during memory processes. The cholinergic system plays an important role in regulating vigilance states and in generating theta rhythm. This study aims to analyse the effects of the muscarinic agonist pilocarpine (120 and 360 microg, i.c.v.) on h...

Merker suggests that the thalamocortical system is not an essential system for consciousness, but, instead, that the midbrain reticular system is responsible for consciousness. Indeed, the latter is a crucial system for consciousness, when consciousness is regarded as the waking state. However, when consciousness is regarded as phenomenal conscious...

A device was developed to measure in a fast way the electroencephalogram (EEG) of broiler chickens in a non-invasive way. The 'chicken EEG clamp' (CHEC) consists of a framework with two pointed electrodes, fitting as a clamp around the chicken's head. The EEG is recorded by the two active electrodes firmly contacting the skin overlying over the mid...

The aim of this study was to investigate how the processing of auditory stimuli is affected by the simultaneous presentation of visual stimuli. This was approached in an active and passive condition, during which a P3 was elicited in the human EEG by single auditory stimuli. Subjects were presented tones, either alone or accompanied by the simultan...

Transcranial magnetic stimulation (TMS) impulses, (0.5 Hz, 3 impulses) were presented at threshold intensity to male WAG/Rij rats. One group received stimuli, which involved motor responses of hindlimbs, rats of the second group received sham stimulation. Electrocorticograms (ECoG) were recorded before and up to 2 hr from the moment of transcranial...

The main aim was to track the dynamics of pattern-learning using single-trial event-related potentials (ERPs). A new 'learning-oddball' paradigm was employed presenting eight random targets (the 'no-pattern') followed by eight regular targets (the 'pattern'). In total, six repetitions of the 'no-pattern' followed by the 'pattern' were presented. We...

The continuous Morlet wavelet transform was used for the analysis of the time-frequency pattern of spike-wave discharges (SWD) as can be recorded in a genetic animal model of absence epilepsy (rats of the WAG/Rij strain). We developed a new wavelet transform that allows to obtain the time-frequency dynamics of the dominating rhythm during the disch...

Anaesthesiologists need parameters that measure the depth of anaesthesia. In the context of this need, the present study investigated in rats how two variables from the electroencephalogram, the burst suppression ratio and effective correlation dimension correlated with a measure of anaesthetic depth as measured in the strength of a noxious withdra...

In WAG/Rij rats the pair linear correlation r was calculated for bipolar recordings in fronto-temporal, fronto-occipital and occipito-temporal zones of both hemispheres as well as in paleocerebellar cortex (culmen). It was shown that development of SWD bursts resulted in interhemispheric decreases of correlation between the right occipito-temporal...

Narcolepsy is associated with lowered vigilance. Diurnal variation in vigilance appears altered, but the exact nature of this change is unclear. It was hypothesized that the homeostatic sleep drive is increased in narcolepsy. Decreased levels of vigilance are reflected in low frequency band power in the electroencephalogram (EEG), so these frequenc...

To study the role of the cortex and sub-cortical structures in the generation of epileptic spike-wave discharges in more detail, cortical and striatal activity was eliminated by the induction of spreading depression in a non-invasive way. EEG and DC potentials were recorded from the cortex and striatum of WAG/Rij rats. Several of these rats show tw...

Both physical and mental effort are thought to affect vigilance. Mental effort is known for its vigilance declining effects, but the effects of physical effort are less clear. This study investigated whether these two forms of effort affect the EEG and subjective alertness differently. Participants performed a physical task and were subsequently pr...

This study assessed the feasibility of online calculation of the correlation integral (C(r)) aiming to apply C(r)-derived statistics. For real-time application it is important to reduce