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Short-term facilitation and depression have a profound influence on transmission at many glutamatergic synapses, particularly during trains of stimuli. A major component of these processes is postsynaptic receptor desensitization. Both presynaptic and postsynaptic mechanisms can contribute to synaptic efficacy, but it is often difficult to define their(More)
1. A hyperpolarization-activated non-specific cation current, I(h), was examined in bushy cell bodies and their giant presynaptic terminals (calyx of Held). Whole-cell patch clamp recordings were made using an in vitro brain slice preparation of the cochlear nucleus and the superior olivary complex. The aim was to characterise I(h) in identified cell bodies(More)
An average-response model of depression at the calyx of Held, a giant glutamatergic synapse in the mammalian auditory pathway, is presented. The model is ÿt to experimentally recorded EPSC amplitudes resulting from 10 to 100 Hz presynaptic stimulation for 1 s. This data exhibits a strong depression of the EPSC amplitude. The model best ÿts the time course(More)
Presynaptic group III metabotropic glutamate receptor (mGluR) activation by exogenous agonists (such as L-2-amino-4-phosphonobutyrate (L-AP4)) potently inhibit transmitter release, but their autoreceptor function has been questioned because endogenous activation during high-frequency stimulation appears to have little impact on synaptic amplitude. We(More)
The neuron-specific potassium-chloride cotransporter 2 (KCC2) plays a crucial role, by controlling chloride extrusion, in the development and maintenance of inhibitory neurotransmission. Although it is now well established that activity-dependent mechanisms can down regulate KCC2 gene expression, the role of post-translational mechanisms in controlling KCC2(More)
The study of synaptic transmission in brain slices generally entails the patch-clamping of postsynaptic neurones and stimulation of identified presynaptic axons using a remote electrical stimulating electrode. Although patch recording from postsynaptic neurones is routine, many presynaptic axons take tortuous turns and are severed in the slicing procedure,(More)
The calyx of Held is a giant glutamatergic synapse in the mammalian auditory pathway designed to ensure faithful transmission of high frequency action potential trains. Pre-and postsynaptic recordings from this synapse reveal several forms of facilitation and depression. A computational model of synaptic transmission has been developed to investigate the(More)
The activation of ligand-gated ion channels is thought to depend solely on the binding of chemical neurotransmitters. In this study, we demonstrate that kainate (KA) ionotropic glutamate receptors (iGluRs) require not only the neurotransmitter L-glutamate (L-Glu) but also external sodium and chloride ions for activation. Removal of external ions traps KA(More)
The thalamus is a major relay and integration station in the central nervous system. While there is a large body of information on the firing and network properties of neurons contained within sensory thalamic nuclei, less is known about the neurons located in midline thalamic nuclei, which are thought to modulate arousal and homeostasis. One midline(More)
Activation of presynaptic receptors plays an important role in modulation of transmission at many synapses, particularly during high-frequency trains of stimulation. Adenosine-triphosphate (ATP) is coreleased with several neurotransmitters and acts at presynaptic sites to reduce transmitter release; such presynaptic P2X receptors occur at inhibitory and(More)