Oxycodone, a semisynthetic opioid analgesic with actions similar to morphine, is extensively prescribed for treatment of moderate to severe acute pain. Given that glutamate plays a crucial role in mediating pain transmission, the purpose of this study was to investigate the effect of oxycodone on glutamatergic synaptic transmission in rat hippocampal CA3 area, which is associated with the modulation of nociceptive perception. Whole-cell patch-clamp recordings revealed that oxycodone effectively reduced presynaptic glutamate release, as detected by decreased frequencies of spontaneous excitatory postsynaptic currents (sEPSCs) and miniature EPSCs (mEPSCs), without eliciting significant changes in the amplitudes of sEPSCs and mEPSCs and glutamate-evoked inward currents. The inhibitory effect of oxycodone on the frequency of sEPSCs was blocked by the nonselective opioid receptor antagonist naloxone. In addition, oxycodone suppressed burst firing induced by 4-aminopyridine and tonic repetitive firing evoked by the applied depolarizing current. These results suggest that oxycodone inhibits spontaneous presynaptic glutamate release possibly by activating opioid receptors and consequently suppressing the neuronal excitability of hippocampal CA3 neurons.
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http://dx.doi.org/10.1139/cjpp-2020-0469 | DOI Listing |
Trimethyltin chloride (TMT), an organotin compound with potent neurotoxicity, is widely used as a heat stabilizer for plastics. However, the precise pathogenic mechanism of TMT remains incompletely elucidated, and there persists a dearth of sensitive detection methodologies for early diagnosis of TMT. In this study, Sprague-Dawley rats were treated with 10 mg/kg TMT to simulate acute exposure in humans.
View Article and Find Full Text PDFExp Anim
January 2025
Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia.
Status epilepticus is linked to cognitive decline due to damage to the hippocampus, a key structure involved in cognition. The hippocampus's high vulnerability to epilepsy-related damage is the main reason for this impairment. Convulsive seizures, such as those observed in status epilepticus, can cause various hippocampal pathologies, including inflammation, abnormal neurogenesis, and neuronal death.
View Article and Find Full Text PDFNeurobiol Aging
December 2024
University of Nebraska Medical Center, College of Medicine, Department of Neurological Sciences, Omaha, NE, USA. Electronic address:
Neurodegenerative Tauopathies are a part of several neurological disorders and aging-related diseases including, but not limited to, Alzheimer's Disease, Frontotemporal Dementia with Parkinsonism, and Chronic Traumatic Encephalopathy. The major hallmarks present in these conditions include Tau pathology (composed of hyperphosphorylated Tau tangles) and synaptic loss. in vivo studies linking Tau pathology and mitochondrial alterations at the synapse, an avenue that could lead to synaptic loss, remain predominantly scarce.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Instituto de Neurociencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2340000, Chile.
BK channels can control neuronal function, but their functional relevance in activity-dependent changes of synaptic function remains elusive. Here, we report that repetitive low-frequency stimulation activates BK channels through 12(S)HPETE, an arachidonic acid metabolite, produced downstream of postsynaptic metabotropic glutamate receptors (mGluRs) to trigger long-term depression (LTD) at CA3-CA1 synapses in hippocampal slices from P7-P10 mice. Activation of BK channels is subunit specific, as paxilline but not iberiotoxin blocked mGluR-LTD.
View Article and Find Full Text PDFPharmaceuticals (Basel)
December 2024
School of Chinese Pharmacy, Beijing University of Chinese Medicine, Beijing 102488, China.
: Baroni (HCB) is a traditional herb for the treatment of depression in China. However, the active constituents and the underlying mechanisms of its antidepressant effects remain unclear. The aim of this study was to identify the bioactive constituents of HCB and elucidate its underlying mechanism for the treatment of depression.
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