SK2- and KV4.2-containing K+ channels modulate evoked synaptic potentials in CA1 pyramidal neurons. Each is coupled to a distinct Ca2+ source that provides Ca2+-dependent feedback regulation to limit AMPA receptor (AMPAR)- and NMDA receptor (NMDAR)-mediated postsynaptic depolarization. SK2-containing channels are activated by Ca2+ entry through NMDARs, whereas KV4.2-containing channel availabil...

Recent studies suggest a role for the arachidonic acid-derived epoxyeicosatrienoic acids (EETs) in attenuating epileptic seizures. However, their effect on neurotransmission has never been investigated in detail. Here, we studied how 11,12- and 14,15 EET affect excitability and excitatory neurotransmission in mouse hippocampus. 11,12 EET (2 μM), but not 14,15 EET (2 μM), induced the opening of ...

Previous studies have shown that GABA can have a depolarizing and excitatory action through GABA(A) receptors in mature CNS neurons in vitro. However, it remains unknown whether this occurs under physiological conditions. In this study, using intracellular recording and staining in vivo technique, we show a late depolarizing postsynaptic potential (L-PSP) in CA1 pyramidal neurons of adult Wista...

Severe autonomic dysfunction, including the loss of control of the cardiovascular, respiratory, and gastrointestinal systems, is a common comorbidity of stroke and other bleeding head injuries. Previous studies suggest that this collapse of autonomic control may be caused by thrombin acting on astrocytic protease-activated receptors (PAR1) in the hindbrain. Using calcium imaging and electrophys...

Whole cell currents and miniature glutamatergic synaptic events (minis) were recorded in vitro from cardiac vagal neurons in the nucleus ambiguus using the patch-clamp technique. We examined whether voltage-dependent calcium channels were involved in the nicotinic excitation of cardiac vagal neurons. Nicotine evoked an inward current, increase in mini amplitude, and increase in mini frequency i...

N-Methyl-d-aspartate receptors (NMDARs) play diverse roles in synaptic transmission, synaptic plasticity, neuronal development and neurological diseases. In addition to their postsynaptic expression, NMDARs are also expressed in presynaptic terminals at some central synapses, and their activation modulates transmitter release. However, the regulatory mechanisms of NMDAR-dependent synaptic trans...

Background: Ketamine is a commonly used intravenous anesthetic which produces dissociation anesthesia, analgesia, and amnesia. The mechanism of ketamine-induced synaptic inhibition in high-level cortical areas is still unknown. We aimed to elucidate the effects of different concentrations of ketamine on the glutamatergic synaptic transmission of the neurons in the primary somatosensory cortex b...

Cardioinhibitory cardiac vagal neurons (CVNs) do not receive inspiratory-related excitatory inputs under normal conditions. However, excitatory purinergic and serotonergic pathways are recruited during inspiratory activity after episodes of hypoxia and hypercapnia (H/H). Prenatal nicotine (PNN) exposure is known to dramatically change cardiorespiratory responses and decrease the ability to resu...

Methylmercury (MeHg; 10-100 microM) induced a spontaneous, transient, slow inward current in Purkinje cells in rat cerebellar slices. Insensitivity of this current to tetrodotoxin suggests that its generation is not related to presynaptic firing. The present study was designed to attempt to identify the ionic origin of this current. Neither Gd(3+), a nonspecific cation channel blocker, nor tetr...

Nitric Oxide (NO) is released from parallel fibers (PFs) after PF stimulation. NO-cGMP signaling is essential for long-term depression (LTD) in cerebellar PF-Purkinje cell synapses, which also exhibit presynaptic long-term potentiation (LTP) after tetanic PF stimulation. This LTP is dependent on cAMP but not NO-cGMP signaling. In this study, we analyzed long-term changes of NO release from PFs ...