Sepsis-Induced Changes in Spectral Segregation and Kinetics of Hippocampal Oscillatory States in Rats.

Sepsis-associated encephalopathy (SAE) is a frequent severe complication of sepsis and the systemic inflammatory response syndrome, associated with high mortality and long-term neurologic consequences in surviving patients. One of the main clinical signs of SAE are discontinuous sleep periods that are fragmented by frequent awakenings. Although this brain state fragmentation strongly impacts the functionality of the nervous and other systems, its underlying network mechanisms are still poorly understood.

Power spectrum slope is related to motor function after focal cerebral ischemia in the rat.

Electroencephalography (EEG) changes across vigilance states have been observed after ischemic stroke in patients and experimental stroke models, but their relation to functional recovery remains unclear. Here, we evaluate motor function, as measured by single pellet reaching (SPR), as well as local EEG changes in nonrapid eye movement (NREM), rapid eye movement (REM), and wakefulness during a 30 day recovery period after middle cerebral artery occlusion or sham surgery in rats. Small cortical infarcts resulted in poor SPR performance and induced widespread changes in EEG spectra in the ipsilesional hemisphere in all vigilance states, without causing major changes in sleep-wake architecture.

Motor skill learning and reward consumption differentially affect VTA activation.

Dopamine release from the ventral tegmental area (VTA) terminals in the primary motor cortex (M1) enables motor skill acquisition. Here, we test the hypothesis that dopaminergic VTA neurons projecting to M1 are activated when rewards are obtained during motor skill acquisition, but not during task execution at plateau performance, or by rewards obtained without performing skilled movements. Rats were trained to perform a skilled reaching task for 3 days (acquisition) or 7 days (plateau).

Investigating Motor Skill Learning Processes with a Robotic Manipulandum.

Skilled reaching tasks are commonly used in studies of motor skill learning and motor function under healthy and pathological conditions, but can be time-intensive and ambiguous to quantify beyond simple success rates. Here, we describe the training procedure for reach-and-pull tasks with ETH Pattus, a robotic platform for automated forelimb reaching training that records pulling and hand rotation movements in rats. Kinematic quantification of the performed pulling attempts reveals the presence of distinct temporal profiles of movement parameters such as pulling velocity, spatial variability of the pulling trajectory, deviation from midline, as well as pulling success.

Protein Synthesis Inhibition in the Peri-Infarct Cortex Slows Motor Recovery in Rats.

Neuroplasticity and reorganization of brain motor networks are thought to enable recovery of motor function after ischemic stroke. Especially in the cortex surrounding the ischemic scar (i.e.

Hormonal, hypothalamic and striatal responses to reduced body weight gain are attenuated in anorectic rats bearing small tumors.

Lack of compensatory or even reduced food intake is frequently observed in weight-losing cancer patients and contributes to increased morbidity and mortality. Our previous work has shown increased transcription factor expression in the hypothalamus and ventral striatum of anorectic rats bearing small tumors. mRNA expression of molecules known to be involved in pathways regulating appetite in these structures was therefore assessed in this study.

Sleep homeostasis in the rat is preserved during chronic sleep restriction.

Sleep is homeostatically regulated in all animal species that have been carefully studied so far. The best characterized marker of sleep homeostasis is slow wave activity (SWA), the EEG power between 0.5 and 4 Hz during nonrapid eye movement (NREM) sleep.

Sleep restriction by forced activity reduces hippocampal cell proliferation.

Mounting evidence suggests that sleep loss negatively affects learning and memory processes through disruption of hippocampal function. In the present study, we examined whether sleep loss alters the generation, differentiation, and survival of new cells in the dentate gyrus. Rats were sleep restricted by keeping them awake in slowly rotating drums for 1 day or repeatedly for 20 h/day over a period of 8 days.