Spectral analysis of electrocortical brain activity in rat model of aluminium intoxication

Cilj ove teze je prikaz metoda za kvalitativnu i kvantitativnu analizu moždane aktivnosti. Ujedno je matematički urađena biomedicinska aproksimacija rezultata. Animalni model intoksikacije aluminijumom je korišćen zbog rasprostranjenosti aluminijuma u prirodi i okruženju. Aluminijum ima selektivno neurotoksično dejstvo na pojedine delove mozga. Ujedno neurotoksičnost aluminijuma ima za posledicu izmenjenu aktivnost celog mozga, ali i specifično dejstvo na pojedine moždane funkcije. Animalni model nudi mogućnost više parametara i može se koristiti za izučavanje neurotoksičnosti aluminijuma pod različitim okolnostima. Procesi koji prate neurotoksičnost mogu se porediti sa promenama koje se javljaju u akutnim i hroničnim stanjima bolesti. Spektralna analiza zasnovana na Furijerovoj transformaciji daje opis promena elektrokortikalne aktivnosti po frekventnim oblastima. Poređenje spektara snage i njihova statistička analiza omogućavaju kvantifikaciju promena. Praćena je elektrokortikalna aktivnost parijetalnog korteksa i malog mozga kako bi se obuhvatila sva tri parametra intoksikacije: akumulacija u tkivu, lokalno izmenjena aktivnost neurona i promena regulatorne funkcije - plastičnost i adaptabilnost mozga. Eksperimentalni dizajn podrazumeva variranje parametara intoksikacije (aplikacija aluminijuma, moždana struktura, doza, starost, soj, fiziološko stanje). Na osnovu dobijenih podataka definisani su efekti neurotoksičnosti aluminijuma. Varijabilnost parametara fizioloških promena i efekata neurotoksičnosti su matematički analizirani. Rezultati ukazuju da promena moždane aktivnosti može biti graduisana tako da može poslužiti kao dijagnostičko-prognostički parametar patofiziološkog stanja. Ova studija ima multidisciplinarni značaj jer obrađuje različite aspekte - biološki, fiziološki i medicinski.The aim of the study was quantitative and qualitative analysis of electrocortical brain activity in rat model of aluminium intoxication. We used animal model of aluminium intoxication becouse aluminium toxicity is widespread in nature. Aluminium has selective effects on different brain regiones. Animal model included different variables, so it can be used to study neurotoxicity in different conditiones. Also, processes due to neurotoxicity can be compared with state of some acute or chronic diseases. Spectral analysis was based on Fast Fourie Transform and changes of electrocortical activity was obsreved in relation to frequency ranges. Comparation of power spectra and statistic analyses was used for quantification of changes in brain activity. We recorded electrocortical activity of parietal cortex and cerebellum to include all parameters of intoxication: acumulation in tissue, changes of neuronal local group activity and changes in regulatory function - plasticity and adaptability of brain. Experimental procedure included different parametars of intoxication - aplication of aluminium, brain structure, doses, age, straint and physiological state of animals. Based on obtained data we define effects of neurotoxicity. Biological parameters, such as neurotoxical effects, physiological change and intoxication are matematicaly analyzed. Results suggest that the change of brain activity can be used in diagnoses and prognoses of pathophisiological state. This study presents synthesis of biological, physiological and medical aspect

Protoplast patch-clamping using an upright microscope with a movable stage

Investigating membrane properties of plants is a challenging task, considering that success ofexperiments is highly dependent on the possibility to isolate metabolically active protoplasts thatcan withstand membrane current recordings. The aim of the present work is to obtain viableprotoplasts derived from root cells of Pisum sativum that can be used for the whole-cell patchclamp. We designed the procedure of the pea protoplasts isolation that delivers stable protoplastswith preserved membrane integrity suitable for electrophysiological experiments. We applied acustom approach for patch-clamping protoplasts using a microscope with a movable microscopestage. We recorded prominent inward and prominent outward types of membrane current profiles ofprotoplasts. Obtained data indicate that optimized isolation protocol and custom system for patchclamping, can be applied to study membrane properties of root protoplasts.Čupić Ž, Anić S, editors. Proceedings: Physical Chemistry 2022, Vol. 1.: 16th International Conference on Fundamental and Applied Aspects of Physical Chemistry; 2022 Sep 26-30; Belgrade, Serbia. Belgrade: Society of Physical Chemists of Serbia; 2022. p. 271-4

Psychomotor activity and body weight gain after exposure to low ribavirin doses in rats: role of treatment duration

Clinically-related basic studies on the behavioral effects of ribavirin treatment are still lacking despite its wide use as an antiviral medication. This paper considers the effects of low ribavirin doses (10, 20 and 30 mg/kg/day) on psychomotor activity (novelty-induced exploratory behavior, d-amphetamine (AMPH, 1.5 mg/kg, intraperitoneal)-induced motor activity), and body weight gain in socially undisturbed adult male Wistar rats 24 h after the first, seventh and fourteenth once-a-day injection. Low doses of ribavirin were tested in an attempt to avoid the recognized systemic side effects related to high-dose usage. None of the singly applied ribavirin doses affected exploratory/spontaneous and AMPH-induced motor behavior (locomotion, stereotypy-like and vertical activity), however, body weight gain was significantly lower after treatment with 30 mg/kg of ribavirin. The 7- and 14-day treatments with 10 and 30 mg/kg/day of ribavirin significantly suppressed novelty-induced locomotion and body weight gain; the 14-day treatment with ribavirin at a dose of 30 mg/kg/ day decreased AMPH-induced stereotypy. These findings indicate that repeated application (up to 14 days) of low ribavirin doses results in low novelty-induced locomotion along with reduced weight gain, accentuating the existence of a U-shaped dose-response relationship with a prolonged duration of ribavirin treatment

Monitoring the progressive increase of the longest episode of spontaneous movements in Guinea pig fetus

The aim of this work was to determine the changes in the duration of spontaneous movements in the guinea pig fetus after the appearance of its first movements. Every day from the 25th to the 35th gestation day, one fetus from each of twenty pregnant animals was examined by ultrasound. Fetal movements were observed for 5 min. The episode with the longest period of movement was taken into consideration and was recorded as: 3 s. Days 25 and 26 were characterized by episodes lasting 3 s (χ2 = 140.51 p <0.05). Tracking the dynamics of progressive increases in the longest episode of spontaneous movement could be a useful factor in estimating the maturity and condition of a fetus.Projekat ministarstva br. 175006/201

Age-related changes in the content of insulin: Like growth factor-l in rat brain

Although there has been extensive research on the effect of IGF-I on muscles and bone tissue, the effect on brain aging has received little attention. We investigated the IGF-I content in brains of differently aged rats. The IGF-I contents in cerebellar and cerebral cortex were found to be higher in immature rats (4-5 days old) compared to young adult (2.5 months old) and middle-aged (7.5-9 months old) rats. However, the decrease of mean IGF-I in middle-aged rats compared to immature animals was statistically significant only in the cerebellar codex. Our results indicate that IGF-I content decreases through the lifespan and maybe selectively in some brain regions.Vršena su istraživanja insulinu sličnog faktora rasta (IGF-I) na mišićno i koštano tkivo, ali je posvećena mala pažnja efektu na mozak u toku starenja. Mi smo ispitivali sadržaj IGF-I u moždanom tkivu pacova različite starosti. Nađeno je da su IGF-I koncentracije u kori malog mozga kao i velikog mozga mladih pacova (4-5 dana starih) više u poređenju sa sadržajima grupe tek-odraslih pacova starosti 2,5 meseca i grupe nešto starijih odraslih pacova (7,5-9 meseci starih). Međutim, smanjenje koncentracije IGF-I sadržaja samo u kori malog mozga nešto starijih pacova (7,5-9 meseci) bilo je značajno u odnosu na vrednosti u novorođenih (4-5 dana starih pacova). Naši rezultati ukazuju da IGF-I opada tokom života i moguće - selektivno u određenim moždanim regionima.nul

Age-related changes in the content of insulin: Like growth factor-l in rat brain

Although there has been extensive research on the effect of IGF-I on muscles and bone tissue, the effect on brain aging has received little attention. We investigated the IGF-I content in brains of differently aged rats. The IGF-I contents in cerebellar and cerebral cortex were found to be higher in immature rats (4-5 days old) compared to young adult (2.5 months old) and middle-aged (7.5-9 months old) rats. However, the decrease of mean IGF-I in middle-aged rats compared to immature animals was statistically significant only in the cerebellar codex. Our results indicate that IGF-I content decreases through the lifespan and maybe selectively in some brain regions.Vršena su istraživanja insulinu sličnog faktora rasta (IGF-I) na mišićno i koštano tkivo, ali je posvećena mala pažnja efektu na mozak u toku starenja. Mi smo ispitivali sadržaj IGF-I u moždanom tkivu pacova različite starosti. Nađeno je da su IGF-I koncentracije u kori malog mozga kao i velikog mozga mladih pacova (4-5 dana starih) više u poređenju sa sadržajima grupe tek-odraslih pacova starosti 2,5 meseca i grupe nešto starijih odraslih pacova (7,5-9 meseci starih). Međutim, smanjenje koncentracije IGF-I sadržaja samo u kori malog mozga nešto starijih pacova (7,5-9 meseci) bilo je značajno u odnosu na vrednosti u novorođenih (4-5 dana starih pacova). Naši rezultati ukazuju da IGF-I opada tokom života i moguće - selektivno u određenim moždanim regionima.nul

Electrocortical spectral analysis and fractal methods for assessing the effects of unilateral brain injury on rat cerebellum

We used electrocortical spectral analysis and fractal methods for assessing the effects of unilateral, single brain injury on cerebellum. Cerebellar electrocortical activity was recorded in control state (before the injury) and after a single brain injury of the cerebellar cortex in anesthetized rats. We noticed that the mean power in gamma high-frequency domain (32-128 Hz) of the cerebellum, was increased after the first brain injury, while after a two-week recovery, it was larger than before the injury. The unilateral brain injury induced a permanent increase of the mild gamma activity in both the left and the right side of cerebellum cortex, but there was no further increase after the lesion was repeated. Our recent electrophysiological study on the cerebellum (Culic et al., 2005) suggested that the mean power spectra of the cerebellar cortical activity in the gamma frequency range might be the indicator of acute single focal brain injury. However, there is insufficient information on the effects of the repeated brain injury on the cerebellar electrocortical activity and morphology. There was no significant difference between the absolute and the relative mean power of the left and the right paravermal cortical activity (before, as well as, after the injury), in each of the animals tested afterwards, but there were differences between the left and the right side of cerebellum in experimental animals. Repeated injury of the cerebellar cortical areas, is strengthened by morphological changes in the cerebellar hemisphere, and shows a decrease in delta and an increase in gamma range.Archives Italiennes de Biologie (2016), 154(4): 118-12

Use of the Hurst Exponent for Analysis of Electrocortical Epileptiform Activity Induced in Rats by Administration of Camphor Essential Oil or 1,8-Cineole

In this study, we investigated the presence of long-range correlation effects in the electrocortical activity of rats using the Hurst exponent (H) calculated by dispersion analysis (DA) and an aggregated variance method (AGV). A slow decline of the autocorrelation function during time expansion and the existence of a correlation between distant time points of electrocorticograms (ECoGs) were shown to be typical of various pathophysiological states. In these cases, the H values were within a 0.5 < H < 1 range. A particularly slow decay of the autocorrelation function is typical of a long-range dependence (LRD). We found that ECoGs after i.p. administrations of camphor essential oil or its main constituent, 1,8-cineole, included attacks of uncontrolled electrical discharges and showed the presence of long-range correlation effects. Such findings are in agreement with recent data obtained by other authors and suggest that initiation of seizures can be predicted by certain ECoG indices. We estimated the critical period where the H values for ECoGs containing uncontrolled electrical discharges continuously increased within a few minutes before the attack. We believe that the AGV demonstrates certain advantages over DA in calculations of the H.Serbian Ministry of Science and Technological Development [14021

Estimation of parameter k(max) in fractal analysis of rat brain activity

We recorded electrocortical activity in anesthetized rats and constructed kmax new self-similar time series, applying Higuchi's algorithm. The aim of this study was to estimate value of the parameter k(max). in order to obtain fractal dimension values as an optimum measure of biosignal change. After our analysis, electrocortical activity recordings resulted in a family of curves f(k(max)). Three regions could be distinguished 2 lt = k(max). lt 8, with a U-shape; 8 lt = k(max) lt = 30, with a steeper quasilinear increase; and k(max) >= 30, with a smaller slope quasilinear increase. We suggest the optimum region for k(max): 8 lt k(max) lt 18, specifically k(max) = 8

Fractal analysis of artificial and cerebellar signals at sampling frequencies of 32-4096 Hz

The aim of this study was to investigate the effects of varying sampling frequencies on fractal analysis of artificial and cerebellar signals. Applying Higuchi's algorithm, we calculated fractal dimension (FD) values of sinus function and rat cerebellar signals (before and after acute brain injury). Various sampling frequences of an artificial signal (as of sinus function, for example) may essentially change the function graphic and therefore the corresponding fractal dimension. Following the acute brain injury, we found an increase of FD values of cerebellar signals at sampling frequencies of 128, 256, 512 and 1024 Hz. We concluded that optimum sampling frequency range of cerebellar signals for FD analysis is 128-1024 Hz