Jelena Ciric

Topography of the sleep/wake states related EEG microstructure and transitions structure differentiates the functionally distinct cholinergic innervation disorders in rat

In order to identify the differences for the onset and progression of functionally distinct cholinergic innervation disorders, we investigated the effect of bilateral nucleus basalis (NB) and pedunculopontine tegmental nucleus (PPT) lesions on sleep/wake states and electroencephalographic (EEG) microstructure in rats, chronically implanted for sleep recording. Bilateral NB lesion transiently altered Wake/NREM duration within the sensorimotor cortex, and Wake/REM duration within the motor cortex, while there was no change in the sleep/wake states distributions following the bilateral PPT lesion. Bilateral PPT lesion sustainably increased the Wake/REM and REM/Wake transitions followed by inconsistent dysregulation of the NREM/REM and REM/NREM transitions in sensorimotor cortex, but oppositely by their increment throughout four weeks in motor cortex. Bilateral NB lesion sustainably decreased the NREM/REM and REM/NREM transitions during four weeks in the sensorimotor cortex, but oppositely increased them in the motor cortex. We have shown that the sustained beta and gamma augmentation within the sensorimotor and motor cortex, and across all sleep/wake states, simultaneously with Wake delta amplitude attenuation only within the sensorimotor cortex, were the underlying EEG microstructure for the sleep/wake states transitions structure disturbance following bilateral PPT lesion. In contrast, the bilateral NB lesion only augmented REM theta in sensorimotor cortex during three weeks. We have shown that the NB and PPT lesions induced differing, structure-related EEG microstructure and transition structure disturbances particularly expressed in motor cortex during NREM and REM sleep. We evidenced for the first time the different topographical expression of the functionally distinct cholinergic neuronal innervation impairment in rat.

Impact of anesthetic regimen on the respiratory pattern, EEG microstructure and sleep in the rat model of cholinergic Parkinson's disease neuropathology.

OBJECTIVES We hypothesized that the impact of distinct anesthetic regimens could be differently expressed during anesthesia and on post-anesthesia sleep in the neurodegenerative diseases. Therefore, we followed the impact of ketamine/diazepam and pentobarbital anesthesia in a rat model of the severe Parkinsons disease cholinergic neuropathology on the electroencephalographic (EEG) microstructure and respiratory pattern during anesthesia, and on the post-anesthesia sleep. METHODS We performed the experiments on adult, male, spontaneously breathing Wistar rats chronically instrumented for sleep recording. The bilateral pedunculopontine tegmental nucleus (PPT) lesion was done by ibotenic acid microinfusion. Following postoperative recovery, we recorded sleep for 6h, induced anesthesia 24h later using ketamine/diazepam or pentobarbital, and repeated sleep recordings sessions 48h and 6days later. During 20min of each anesthesia we recorded both the EEG and respiratory movements. For sleep and EEG analysis, Fourier analysis was applied on 6-h recordings, and each 10-s epoch was differentiated as a state of wakefulness (Wake), non-rapid eye movement (NREM) or rapid eye movement (REM). Additionally, the group probability density distributions of all EEG frequency band relative amplitudes were calculated for each state, with particular attention during anesthesia. For respiratory pattern analysis we used Monotone Signal Segments Analysis. The PPT lesion was identified through nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry. RESULTS AND CONCLUSIONS Our data show that the ketamine/diazepam anesthetic regimen in the PPT-lesioned rats induces more alterations in the EEG microstructure and respiratory pattern than does the pentobarbital anesthesia. In addition, the equal time required to establish an anesthetized state, and the long-term effect on post-anesthesia sleep in the PPT-lesioned vs. control rats suggest this anesthetic regimen as potentially more beneficial both for anesthesia induction and for post-anesthesia sleep in the surgical procedures of the elderly, and Parkinsons, and Alzheimers patients.

Age-related disorders of sleep and motor control in the rat models of functionally distinct cholinergic neuropathology.

We studied the impact of aging during sleep in the rat models of Alzheimers (AD) and Parkinsons (PD) disease cholinergic neuropathology to determine the possible different and earlier onset of age-related sleep disorder during the neurodegenerative diseases vs. healthy aging. We used the bilateral nucleus basalis (NB) and pedunculopontine tegmental nucleus (PPT) lesioned rats as the in vivo models of functionally distinct cholinergic neuropathology, and we followed the impact of aging on sleep architecture, the electroencephalographic (EEG) microstructure and motor control across sleep/wake states. Our results have shown for the first time that the earliest signs of aging during distinct cholinergic neuropathology were expressed through a different and topographically specific EEG microstructure during rapid eye movement sleep (REM). EEG delta amplitude attenuation within the sensorimotor cortex (SMCx) during REM was the earliest sign of aging in the NB lesion. EEG sigma amplitude augmentation within the motor cortex (MCx) during REM was the earliest sign of aging in the PPT lesion. In addition, aging was differently expressed through the SMCx drive alterations, but it was commonly expressed through the MCx drive alterations during all sleep/wake states. Our study provided evidence of distinct REM sleep disorders and sleep state related cortical drives as the signs of aging onset during functionally distinct cholinergic neuropathologies (NB lesion vs. PPT lesion).

Aging induced cortical drive alterations during sleep in rats

We followed the impact of healthy aging on cortical drive during sleep in rats by using the corticomuscular coherence (CMC). We employed the chronic electrodes implantation for sleep recording in adult, male Wistar rats, and followed the aging impact during sleep from 3 to 5.5 months age. We have analyzed the sleep/wake states architecture, and the sleep/wake state related EEG microstructure and CMCs. We evidenced the topographically distinct impact of aging on sleep/wake states architecture within the sensorimotor (SMCx) vs. motor cortex (MCx) from 4.5 to 5.5 months age. Healthy aging consistently altered only the SMCx sleep/wake states architecture, and increased the delta and beta CMCs through both cortical drives during Wake, but only through the MCx drive during REM. According to the delta and beta CMCs values, aging impact through the SMCx drive was opposite, but it was convergent through the MCx drive during Wake vs. REM, and there was a dual and inverse mode for the motor control during REM.

REM sleep disorder following general anesthesia in rats

Postoperative sleep disorders, particularly the REM sleep disorder, may have a significant deleterious impact on postoperative outcomes and may contribute to the genesis of certain delayed postoperative complications. We have followed the effect of distinct anesthesia regimens (ketamine/diazepam vs. pentobarbital) over 6days following the induction of a stable anesthetized state in adult male Wistar rats, chronically instrumented for sleep recording. In order to compare the effect of both anesthetics in the physiological controls vs. the rats with impaired pedunculopontine tegmental nucleus (PPT) cholinergic innervation, during the operative procedure for the implantation of EEG and EMG electrodes, the bilateral PPT lesion was conducted using ibotenic acid (IBO). We have followed in particular post-anesthesia REM sleep. Our results show the distinct EEG microstructure of the motor cortex during the different stable anesthetized states, and their distinct impact on post-anesthesia REM sleep. In contrast to pentobarbital anesthesia, the ketamine/diazepam anesthesia potentiated the long-lasting post-anesthesia REM statewith higher muscle tone (REM1) vs. REM state with atonia (REM2). Whereas both anesthesias prolonged the post-anesthesia REM sleep duration, the long-term prolongation of the REM1 state was demonstrated only after the ketamine/diazepam anesthesia, first due to the increased number of REM1 episodes, and then due to the prolonged REM1 episodes duration. On the other hand, whereas both anesthetic regimens abolished the prolonged post-anesthesia REM/REM1 sleep and the EEG microstructure disorder during REM sleep, only the pentobarbital abolished the increased NREM/REM/NREM transitions, caused by the PPT lesion. In addition, in the PPT lesioned rats, the ketamine/diazepam anesthesia decreased the Wake/NREM/Wake transitions while the pentobarbital anesthesia decreased the Wake/REM/Wake transitions. Our present study suggests pentobarbital anesthesia as being highly beneficial for post-anesthesia REM sleep in the physiological condition as well as during PPT cholinergic neuropathology.

Physicochemical parameters and microbiological status of honey produced in an urban environment in Serbia

Honey is a natural substance produced by honey bees (the genus Apis) enjoyed by people due to its unique nutritional and medicinal properties. The aim of this study was to determine the physicochemical parameters (moisture, ash, water-insoluble content, reducing sugars, sucrose, free acidity, diastase activity, hydroxymethylfurfural, and electrical conductivity) and microbiological status (total number of aerobic mesophilic bacteria, total number of sulfite-reducing clostridia, the presence of Salmonella spp., total numbers of fungi and yeasts and the presence of Clostridium botulinum) in honey (honeydew, blossom, sunflower, acacia, and linden) produced in an urban environment in Serbia. We analyzed 19 apiary samples of honey, collected during the 2011 harvesting season, by using recommendation methods. Physicochemical parameters of the examined honey produced in the urban environment indicated the honeys were of acceptable quality. Bacillus spp. were detected in four honeys, yeasts were detected in three honeys, and Clostridium botulinum type E was detected in one honey using PCR. The current study also showed the presence of diverse honey varieties in Serbia.

Sleep disorder and altered locomotor activity as biomarkers of the Parkinson's disease cholinopathy in rat

HIGHLIGHTSHippocampal sleep disorder is the first and long‐lasting hallmark of PD cholinopathy.High voltage sleep spindle dynamics during REM sleep reflects PD cholinopathy.Hypokinesia reflects impaired cholinergic impact in motor control regulatory network.Amphetamine induces hyperactivity in the hypokinetic rats with PD cholinopathy.Putamen c‐Fos activity reflects re‐organization of motor control in PD cholinopathy. ABSTRACT In order to find out the possible earliest biomarkers of Parkinsons disease (PD) cholinopathy, we followed the impact of bilateral pedunculopontine tegmental nucleus (PPT) lesion in rat on: the cortical and hippocampal sleep/wake states architectures, all sleep states related EEG microstructures, sleep spindles, the basal and stimulated locomotor activity. Sleep and basal locomotor activity in adult Wistar rats were followed during their inactive circadian phase, and throughout the same aging period. The bilateral PPT lesions were done by 0.1 M ibotenic acid (IBO) during the surgical procedure for implantation of the electroencephalographic (EEG) and electromyographic (EMG) electrodes for chronic sleep recording. The cholinergic neuronal loss was identified by NADPH – diaphorase histochemistry. After all sleep and behavioral recording sessions, the locomotor activity was stimulated by d‐amphetamine (d‐AMPH) and the neuronal activity of striatum was followed by c‐Fos immunolabeling. Impaired cholinergic innervation from the PPT was expressed earlier as sleep disorder then as movement disorder, and it was the earliest and long‐lasting at hippocampal and thalamo‐cortical level, and followed by a delayed “hypokinesia”. This severe impact of a tonically impaired PPT cholinergic innervation was evidenced as the cholinergic interneuronal loss of the caudate putamen and as a suppressed c‐Fos expression after stimulation by d‐AMPH. In order how they occurred, the hippocampal non rapid eye movement (NREM) sleep disorder, altered high voltage sleep spindle (HVS) dynamics during rapid eye movement (REM) sleep in the hippocampus and motor cortex, and “hypokinesia” may serve as the biomarkers of PD cholinopathy onset and progression.

Disorders of Sleep and Motor Control During the Impaired Cholinergic Innervation in Rat – Relevance to Parkinson’s Disease

#173022: Neurobiology of sleep in aging and disease - electroencephalographic markers and modeling in the estimation of disorder

Cortico-pontine theta carrier frequency phase shift across sleep/wake states following monoaminergic lesion in rat

This study was aimed to explore the sleep/wake states related cortico-pontine theta carrier frequency phase shift following a systemically induced chemical axotomy of the monoaminergic afferents within a brain of the freely moving rats. Our experiments were performed in 14 adult, male Sprague Dawley rats, chronically implanted for sleep recording. We recorded sleep during baseline condition, following sham injection (saline i.p. 1 ml/kg), and every week for 5 weeks following injection of the systemic neurotoxins (DSP-4 or PCA; 1 ml/kg, i.p.) for chemical axotomy of the locus coeruleus (LC) and dorsal raphe (DR) axon terminals. After sleep/wake states identification, FFT analysis was performed on 5 s epochs. Theta carrier frequency phase shift (∆Φ) was calculated for each epoch by averaging theta Fourier component phase shifts, and the ∆Φ values were plotted for each rat in control condition and 28 days following the monoaminergic lesions, as a time for permanently established DR or LC chemical axotomy. Calculated group averages have shown that ∆Φ increased between pons and cortex significantly in all sleep/wake states (Wake, NREM and REM) following the monoaminergic lesions, with respect to controls. Monoaminergic lesions established the pontine leading role in the brain theta oscillations during all sleep/wake states.

Corrigendum to “The effects of dietary Selenium-yeast level on glutathione peroxidase activity, tissue Selenium content, growth performance, and carcass and meat quality of broilers”

Abstract The present study was conducted to assess effects of selenium (Se)‐yeast supplementation on glutathione peroxidase activity, Se levels in tissues, growth performance, carcass, and meat composition in broilers. A total of 275 one‐d‐old Cobb 500 broilers of both sexes were randomly allotted to 1 of 5 treatments during a 42‐d period. The 5 treatments differed only in Se content: group 1 had no additional Se (background only); groups 2, 3, and 4 received 0.3 mg/kg of added Se from the beginning of the trial until d 21, whereas in the second half of the study (from d 22 to 42), these groups received 0.3, 0.6, and 0.9 mg/kg of added Se, respectively; and group 5 received 0.9 mg/kg of Se for the entire experimental period. At the end of the study, the control group showed significantly lower (P < 0.01) glutathione peroxidase activity in blood plasma compared to Se‐supplemented groups. Regarding Se concentration in various tissues, the groups receiving Se yeast showed higher plasma, feces, and meat Se contents than the control group (P < 0.01). Supplementation of Se improved broilers’ body weight, weight gain and feed conversion ratio (P < 0.01). Dressing percentage was lower in the control group and the group with 0.3 mg/kg of added Se compared to other experimental groups (0.6 and 0.9 mg/kg of dietary Se). The proportion of less valuable carcass parts (wings and legs) was higher (P < 0.01) in the group fed the basal diet compared to groups supplemented with 0.9 mg/kg of Se. Initial and ultimate pH values differed among experimental groups (P < 0.05). Supplementation of Se improved the broilers antioxidative resistance, growth performance, carcass quality, and chemical composition of meat.