This study used an experimental early rehabilitation model combining an enriched environment, multisensory (visual, acoustic and olfactory) stimulation and motor training after traumatic brain injury (via fluid-percussion model) to simulate early multisensory rehabilitation. This therapy will be used by brain injured patients to improve neural plasticity and to restore brain integration functions. Motor dysfunction was evaluated using a composite neuroscore test. Direct structural effects of traumatic brain injury were examined using Fluoro-Jade staining, which allows identification of degenerating neural cell bodies and processes. Animals in the rehabilitation model group performed significantly better when tested for neuromotor function than the animals in standard housing in the 7-day and 15-day interval after injury (7d: p=0.005; 15d: p<0.05). Statistical analysis revealed significantly lower numbers of Fluoro-Jade positive cells (degenerating neurons) in the rehabilitation model group (n=5: mean 13.4) compared to the standard housing group (n=6: mean 123.8) (p<0.005). It appears that the housing of animals in the rehabilitation model led to a clear functional increase in neuromotor functions and to reduced neural loss compared with the animal group in standard housing., M. Lippert-Grüner. M. Maegele, J. Pokorný, D. N. Angelov, O. Švestková, M. Wittner, S. Trojan., and Obsahuje bibliografii a bibliografické odkazy
We investigated how selected electromorphological parameters of myelinated axons influence the preservation of interspike intervals when the propagation of action potentials is corrupted by axonal intrinsic noise. Hereby we tried to determine how the intrinsic axonal noise influences the performance of axons serving as carriers for temporal coding. The strategy of this coding supposes that interspike intervals presented to higher order neurons would minimally be deprived of information included in interspike intervals at the axonal initial segment. Our experiments were conducted using a computer model of the myelinated axon constructed in a software environment GENESIS (GEneral NEural SImulation System). We varied the axonal diameter, myelin sheath thickness, axonal length, stimulation current and channel distribution to determine how these parameters influence the role of noise in spike propagation and hence in preserving the interspike intervals. Our results, expressed as the standard deviation of spike travel times, showed that by stimulating the axons with regular rectangular pulses the interspike intervals were preserved with a microsecond accuracy. Stimulating the axons with pulses imitating postsynaptic currents, greater changes of interspike intervals were found, but the influence of implemented noise on the jitter of interspike intervals was approximately the same., E. Kuriščák, S. Trojan, Z. Wünsch., and Obsahuje bibliografii
Pregnant rats were exposed to intermittent hypobaric hypoxia (at a simulated altitude of 7000 m or 5000 m) and the excitability of cortical neurons of their pups was tested. Stimulation of the sensorimotor cortex of rats prenatally exposed to hypoxia shortened the duration of cortical afterdischarges in 12-day-old rats, but did not change the excitability in 25-day-old animals. Shortening of the first afterdischarge in 35-day-old rats but the prolongation of the first afterdischarge in adult rats (as compared to the duration of cortical afterdischarges in rats not exposed to prenatal hypoxia) were registered. The possible mechanisms of different excitability of cortical neurons in rats prenatally exposed to hypobaric hypoxia are discussed., D. Marešová, I. Valkounová, K. Jandová, J. Bortelová, S. Trojan., and Obsahuje bibliografii
We investigated how selected electromorphological parameters of myelinated axons influence the preservation of interspike intervals when the propagation of action potentials is corrupted by axonal intrinsic noise. Hereby we tried to determine how the intrinsic axonal noise influences the performance of axons serving as carriers for temporal coding. The strategy of this coding supposes that interspike intervals presented to higher order neurons would minimally be deprived of information included in interspike intervals at the axonal initial segment. Our experiments were conducted using a computer model of the myelinated axon constructed in a software environment GENESIS (GEneral NEural SImulation System). We varied the axonal diameter, myelin sheath thickness, axonal length, stimulation current and channel distribution to determine how these parameters influence the role of noise in spike propagation and hence in preserving the interspike intervals. Our results, expressed as the standard deviation of spike travel times, showed that by stimulating the axons with regular rectangular pulses the interspike intervals were preserved with a microsecond accuracy. Stimulating the axons with pulses imitating postsynaptic currents, greater changes of interspike intervals were found, but the influence of implemented noise on the jitter of interspike intervals was approximately the same., E. Kuriščák, S. Trojan, Z. Wünsch., and Obsahuje bibliografii