Učinci carskog reza na peroksidaciju lipida i neke antioksidanse u krvi netom oteljene teladi.

The mode of delivery may have a considerable effect on the state and health of the newborn. Therefore, the purpose of this study was to investigate the effect of a Caesarean section on oxidant and antioxidant status in newborn calves. This study included the neonates of 8 normally calved cows and 8 cows who had undergone by Caesarean section. Malondialdehyde concentrations were significantly higher in the calves delivered by caesarean section compared to the calves of normally calved cows, but catalase activity was significantly lower (P<0.01). Glutathione concentrations tended to increase in the calves delivered by Caesarean section compared to the calves of normally calved cows. There were no significant differences in the glutathione peroxidase activity between the groups. Our results suggest that the malondialdehyde concentrations and catalase activities, which show lipid peroxidation and antioxidant status in newborn calves, change due to Caesarean section. In conclusion, newborn calves are exposed to higher oxidative stress in Caesarean section.Način porođaja može znatno utjecati na stanje i zdravlje novorođenčeta. Stoga je svrha ovoga rada istražiti učinak carskoga reza na oksidacijsko i antioksidacijsko stanje u netom oteljene teladi. Istraživanje je provedeno na osam normalno oteljene teladi i na osam teladi oteljene carskim rezom. Koncentracije malondialdehida bile su značajno veće u teladi oteljene carskim rezom nego li u prirodne oteljene teladi, ali je aktivnost katalaze bila značajno slabija (P<0,01). Koncentracije glutationa bile su povećane u teladi oteljene carskim rezom u odnosu na prirodno oteljenu telad. Nisu bile ustanovljene značajne razlike u aktivnosti glutation peroksidaze među dvjema skupinama. Rezultati upućuju na zaključak da su koncentracije malondialdehida i aktivnost katalaze kao pokazatelji lipidne peroksidacije i antioksidacijskog stanja u novorođene teladi bile promijenjene zbog carskog reza. To govori da je netom oteljena telad zbog carskog reza izložena jačem oksidacijskom stresu

Photoperiod effects on carcass traits, meat quality, and stress response in heart and lung of broilers

This study evaluated effects of photoperiod treatments on slaughter and carcass traits, meat quality, indicators of oxidative stress, and heat shock protein 70 (Hsp70) levels of lung and heart tissues in broilers. Five hundred Ross 308 broiler chicks were used. The treatments consisted of 23 hours of continuous light and one hour of darkness (23L1D), four hours of light followed by two hours of darkness (4L2D), eight hours of light and four hours of darkness (8L4D), and 16 hours of light and eight hours of darkness (16L8D). After 42 days, two birds from each replicate were slaughtered. Birds that had been subjected to 16L8D had lower slaughter, carcass, and breast weights than the other treatments. Significant correlations were observed for slaughter, carcass and breast weights and white stripe. At 10 min post mortem, the pH of the breast was the highest in 23L1D. Breasts from birds subjected to 23L1D and 16L8D had most fat and least protein, while white striping was not different among treatments. The 4L2D treatment resulted in the highest lung glutathione (GSH) concentration. Malondialdehyde (MDA) and GSH concentrations in the heart tissues of broilers from 8L4D and 4L2D were greater than those from 23L1D and 16:8. Glutathione peroxidase (GSH-Px) and superoxide dismutase concentrations were greatest for birds subjected to 16L8D. Heat shock protein 70 was lowest in lung and heart from birds subjected to 8L4D. Thus, shorter and more frequent periods of darkness can be recommended for welfare with little compromise in performance. Keywords: carcass quality, heat shock protein 70, oxidative stress, white strip

The pedunculopontine tegmental nucleus and the nucleus basalis magnocellularis: Do both have a role in sustained attention?

It is well established that nucleus basalis magnocellularis (NbM) lesions impair performance on tests of sustained attention. Previous work from this laboratory has also demonstrated that pedunculopontine tegmental nucleus (PPTg) lesioned rats make more omissions on a test of sustained attention, suggesting that it might also play a role in mediating this function. However, the results of the PPTg study were open to alternative interpretation. We aimed to resolve this by conducting a detailed analysis of the effects of damage to each brain region in the same sustained attention task used in our previous work. Rats were trained in the task before surgery and post-surgical testing examined performance in response to unpredictable light signals of 1500 ms and 4000 ms duration. Data for PPTg lesioned rats were compared to control rats, and rats with 192 IgG saporin infusions centred on the NbM. In addition to operant data, video data of rats' performance during the task were also analysed

The response of a classical Hodgkin–Huxley neuron to an inhibitory input pulse

A population of uncoupled neurons can often be brought close to synchrony by a single strong inhibitory input pulse affecting all neurons equally. This mechanism is thought to underlie some brain rhythms, in particular gamma frequency (30–80 Hz) oscillations in the hippocampus and neocortex. Here we show that synchronization by an inhibitory input pulse often fails for populations of classical Hodgkin–Huxley neurons. Our reasoning suggests that in general, synchronization by inhibitory input pulses can fail when the transition of the target neurons from rest to spiking involves a Hopf bifurcation, especially when inhibition is shunting, not hyperpolarizing. Surprisingly, synchronization is more likely to fail when the inhibitory pulse is stronger or longer-lasting. These findings have potential implications for the question which neurons participate in brain rhythms, in particular in gamma oscillations

Biophysical Basis for Three Distinct Dynamical Mechanisms of Action Potential Initiation

Transduction of graded synaptic input into trains of all-or-none action potentials (spikes) is a crucial step in neural coding. Hodgkin identified three classes of neurons with qualitatively different analog-to-digital transduction properties. Despite widespread use of this classification scheme, a generalizable explanation of its biophysical basis has not been described. We recorded from spinal sensory neurons representing each class and reproduced their transduction properties in a minimal model. With phase plane and bifurcation analysis, each class of excitability was shown to derive from distinct spike initiating dynamics. Excitability could be converted between all three classes by varying single parameters; moreover, several parameters, when varied one at a time, had functionally equivalent effects on excitability. From this, we conclude that the spike-initiating dynamics associated with each of Hodgkin's classes represent different outcomes in a nonlinear competition between oppositely directed, kinetically mismatched currents. Class 1 excitability occurs through a saddle node on invariant circle bifurcation when net current at perithreshold potentials is inward (depolarizing) at steady state. Class 2 excitability occurs through a Hopf bifurcation when, despite net current being outward (hyperpolarizing) at steady state, spike initiation occurs because inward current activates faster than outward current. Class 3 excitability occurs through a quasi-separatrix crossing when fast-activating inward current overpowers slow-activating outward current during a stimulus transient, although slow-activating outward current dominates during constant stimulation. Experiments confirmed that different classes of spinal lamina I neurons express the subthreshold currents predicted by our simulations and, further, that those currents are necessary for the excitability in each cell class. Thus, our results demonstrate that all three classes of excitability arise from a continuum in the direction and magnitude of subthreshold currents. Through detailed analysis of the spike-initiating process, we have explained a fundamental link between biophysical properties and qualitative differences in how neurons encode sensory input

The Changes of the Body Weight and Some Blood Parameters of Pekin Ducklings Dependent on Transportation Duration

Onbasilar, Ebru/0000-0002-1321-0280; ERISIR, Zeki/0000-0003-0420-023X; Erisir, Mine/0000-0001-6209-4792WOS: 000262562100003The effect of transportation on body weight and some blood parameters of hatching Pekin ducklings were investigated. A total of 500 (250 male, 250 female) 1 day-old ducklings (Star 52-Grimaud Freres) were obtained from a commercial hatchery. Upon hatching and on the 4, 8 and 12 h of the transportation, each duckling was weighed to determine their body weights. Before transportation and on the 4, 8 and 12 h of the transportation, necks of 10 male and 10 female ducklings were broken and blood samples were taken. Plasma corticosterone, glucose, cholesterol, triglyceride, AST (Aspartate transaminase), CK (Creatine kinase), total protein, albumin levels and blood H/L (heterophile/lymphocyte) ratios were determined. The body weights, which were 46.1 and 45.7 g for hatching male and female ducklings, fell down to 41.3 and 41.5 g at the end of transportation. During transportation, a total of 4 ducklings died; 1 male and 1 female on the 8 h, 1 male and 1 female on the 12 h. Plasma glucose levels of ducklings decreased up to 8 h of transportation, but increased at 12 h. Plasma corticosterone, cholesterol, triglyceride, AST, total protein, albumin levels and blood H/L ratios increased in transported ducklings due to increasing transportation time