This study assessed whether changes in size or time-course of excitatory postsynaptic potentials (EPSPs) in motoneurons innervating spastic muscle could induce a greater synaptic response, and thereby contribute to reflex hyperexcitability. We compared motor unit (MU) firing patterns elicited by tendon taps applied to both spastic and contralateral (nonspastic) biceps brachii muscle in hemiparetic stroke subjects. Based on recordings of 115 MUs, significantly shortened EPSP rise times were present on the spastic side, but with no significant differences in estimated EPSP amplitude. These changes may contribute to hyperexcitable reflex responses at short latency, but the EPSP amplitude changes appear insufficient to account for global differences in reflex excitability.
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http://dx.doi.org/10.1002/mus.20318 | DOI Listing |
Front Neurol
December 2024
Department of Pediatrics, Peking University First Hospital, Beijing, China.
Introduction: Neonatal seizures are the most common clinical manifestation of neurological dysfunction in newborns, with an incidence ranging from 1 to 5‰. However, the therapeutic efficacy of current pharmacological treatments remains suboptimal. This study aims to utilize genetically modified hamsters with hypertriglyceridaemia (HTG) to investigate the effects of elevated triglycerides on neuronal excitability and to elucidate the underlying mechanisms.
View Article and Find Full Text PDFActa Physiol (Oxf)
February 2025
Institute for Physiology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany.
Aim: Despite dysfunctional vasoactive intestinal polypeptide-positive interneurons (VIP-INs) being linked to the emergence of neurodevelopmental disorders, the temporal profile of VIP-IN functional maturation and cortical network integration remains unclear.
Methods: Postnatal VIP-IN development was traced with patch clamp experiments in the somatosensory cortex of Vip-IRES-cre x tdTomato mice. Age groups were chosen during barrel field formation, before and after activation of main sensory inputs, and in adult animals (postnatal days (P) P3-4, P8-10, P14-16, and P30-36).
eNeuro
January 2025
Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin 53705
Fragile X autosomal homolog 1 (FXR1), a member of the fragile X messenger riboprotein 1 family, has been linked to psychiatric disorders including autism and schizophrenia. Parvalbumin (PV) interneurons play critical roles in cortical processing and have been implicated in FXR1-linked mental illnesses. Targeted deletion of FXR1 from PV interneurons in mice has been shown to alter cortical excitability and elicit schizophrenia-like behavior.
View Article and Find Full Text PDFFASEB J
December 2024
Department of Biological Sciences, Konkuk University, Seoul, South Korea.
The prevalence of depressive disorders in women has been reported in many countries. However, the cellular mechanisms mediating such sex differences in stress susceptibility remain largely unknown. Previously, we showed that lateral habenula (LHb) neurons are more activated in female mice than in male mice by restraint stress.
View Article and Find Full Text PDFNeuroscience
December 2024
Department of Psychology, Concordia University, Montreal, Canada. Electronic address:
Estrogens and progesterone can have rapid effects on neuronal function and can modify the use of spatial navigation strategies dependent upon the prefrontal cortex, striatum, and hippocampus. Here, we assessed the effects of 17β-estradiol (E2), progesterone, and its metabolite allopregnanolone, on evoked excitatory postsynaptic potentials in the infralimbic region of the female rat prefrontal cortex. Field excitatory postsynaptic potentials (fEPSPs) evoked by stimulation of layer I were first characterized by recording responses at multiple depths between the cortical surface and the underlying white matter.
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