The effects of four xanthines (theophylline, 8-phenyltheophylline, isobutylmethylxanthine (IBMX), and 7-benzyl-IBMX) were studied in the hippocampal slice in vitro. These agents increased the excitability of this preparation with 8-phenyltheophylline being the most potent, 7-benzyl-IBMX the least potent, and theophylline and IBMX having intermediate potencies. A similar rank order was observed in terms of the potencies of these xanthines in antagonizing a) electrophysiological responses to adenosine, and b) adenosine-stimulated cyclic AMP formation. These results indicate that the excitatory actions of xanthines in the vivo hippocampus can be most easily explained on the basis of their ability to block adenosine's actions; the CNS excitatory actions of these drugs in vivo may depend upon a similar mechanism of action.
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http://dx.doi.org/10.1007/BF00501365 | DOI Listing |
J Neurosci
January 2025
Department of Neuroscience, Brown University, Providence RI, USA.
Voltage-gated potassium conductances [Formula: see text] play a critical role not only in normal neural function, but also in many neurological disorders and related therapeutic interventions. In particular, in an important animal model of epileptic seizures, 4-aminopyridine (4-AP) administration is thought to induce seizures by reducing [Formula: see text] in cortex and other brain areas. Interestingly, 4-AP has also been useful in the treatment of neurological disorders such as multiple sclerosis (MS) and spinal cord injury, where it is thought to improve action potential propagation in axonal fibers.
View Article and Find Full Text PDFFront Physiol
January 2025
Human Physiology Section of the Department of Pathophysiology and Transplantation, Università Degli Studi, Milano, Italy.
Introduction: Prolonged or strenuous exercise leads to a temporary decrease in muscle function and performance, which interferes with activity of both prime movers and postural muscles. This effect of fatigue has been reported both for single segment movements and for locomotion. However, little is known regarding the effects of fatigue on anticipatory postural adjustments (APAs) during gait initiation, a task in which the control of focal movement should be strictly coupled to a feedforward control of posture.
View Article and Find Full Text PDFFentanyl is a potent synthetic opioid widely used perioperatively and illicitly as a drug of abuse . It is well established that fentanyl acts as a μ-opioid receptor agonist, signaling through Gα intracellular pathways to inhibit electrical excitability, resulting in analgesia and respiratory depression . However, fentanyl uniquely also triggers muscle rigidity, including respiratory muscles, hindering the ability to execute central respiratory commands or to receive external resuscitation.
View Article and Find Full Text PDFStem Cell Res Ther
January 2025
Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Leioa, Bizkaia, 48940, Spain.
Background And Aim: Human dental pulp stem cells (hDPSCs) constitute a promising alternative for central nervous system (CNS) cell therapy. Unlike other human stem cells, hDPSCs can be differentiated, without genetic modification, to neural cells that secrete neuroprotective factors. However, a better understanding of their real capacity to give rise to functional neurons and integrate into synaptic networks is still needed.
View Article and Find Full Text PDFCurr Biol
January 2025
Department of Psychology, University of Virginia, Charlottesville, VA 22904, USA; Department of Biology, University of Virginia, Charlottesville, VA 22904, USA. Electronic address:
Visual motion is a crucial cue for the brain to track objects and take appropriate actions, enabling effective interactions with the environment. Here, we study how the superior colliculus (SC) integrates motion information using asymmetric plaids composed of drifting gratings of different directions and speeds. With both in vivo electrophysiology and two-photon calcium imaging, we find that mouse SC neurons integrate motion direction by performing vector summation of the component gratings.
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