Neuroscience
-
Sleep deprivation (SD) is a common issue in today's society. Sleep is essential for proper cognitive functions, including learning and memory. Furthermore, sleep disorders can alter pain information processing. ⋯ Both drugs reversed all behavioral changes induced by TSD. Furthermore, both drugs reversed the effect of RSD on memory acquisition, while only mecamylamine reversed the effect of RSD on locomotor activity. In conclusion, CA1 nicotinic receptors play a significant role in TSD/RSD-induced behavioral changes.
-
Alzheimer's disease (AD) is the most prevalent type of dementia affecting older people. The identification of biomarkers is increasingly important and would be crucial for future therapy. ⋯ Finally, we showed that in normal erythrocytes, treated in vitro with Aβ1-42 peptide, both band3 phosphorylation and lyn activation occurs. These results suggest that modulation of tyrosine phosphorylation signaling may be evaluated as a potential peripheral marker in AD.
-
The human right inferior frontal cortex (IFC) plays a critical role in response inhibition. It has also been demonstrated that the IFC is heterogeneous and that the ventral part of the IFC (vIFC) is more critical to inhibition of prepotent response tendency. Recent areal parcellation analyses based on resting-state functional connectivity have revealed that the right vIFC consists of multiple functional areas. ⋯ Correlations were significantly stronger in the ventral parcel. Moreover, the ventral parcel exhibited a negative correlation between brain activity during response inhibition and stop-signal reaction time (SSRT), a behavioral measure used to evaluate stopping performance. These dissociation results suggest that the ventral region in the vIFC plays a more central role in the brain network by increasing brain activity, which may further predict better performance of response inhibition.
-
Our choices are often informed by temporally integrating streams of sensory information. This has been well demonstrated in the visual and auditory domains, but the integration of tactile information over time has been less studied. We designed an active touch task in which participants explored a spheroid-shaped object to determine its inclination with respect to the horizontal plane (inclined to the left or the right). ⋯ The behavioral results were fit with a bounded accumulation model and an independent sampling model that assumes no sensory accumulation. The results of model fits favor an accumulation-to-bound mechanism and suggest that participants integrate the first 600 ms of 1800 ms-long stimuli. This means that the somatosensory system benefits from longer streams of information, although it does not make use of all available evidence.
-
Here we investigated effects of intramuscular (i.m.) heating-needle stimulation on persistent muscle nociception evoked by i.m. injection of different doses (50-200 µl) of complete Freund's adjuvant (CFA) in rats. Paw withdrawal reflexes evoked by noxious mechanical and heat stimulation as well as hind limb swelling were determined prior to and two weeks after the CFA injection. The unilateral injection of CFA induced a dose-related and long-lasting (5-14 d), bilateral secondary mechanical hyperalgesia and heat hypoalgesia associated with long-term limb swelling. ⋯ In contrast, the hind limb swelling was not affected by the microinjection of A-317491 into the thalamic VM or MD nucleus. The present study indicates that in the CFA-induced persistent muscle nociception condition, 43 °C heating-needle stimulation selectively increases descending inhibition, which effect is modulated by the thalamic VM nucleus. In addition to the antinociceptive role of P2X3 receptors in the thalamic VM nucleus, P2X3 receptors within the thalamic MD nucleus participate in the descending facilitation evoked by i.m. 46 °C heating-needle stimulation.