Ian D. Forsythe

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Metabotropic glutamate receptors (mGluRs) regulate transmitter release at mammalian central synapses. However, because of the difficulty of recording from mammalian presynaptic terminals, the mechanism underlying mGluR-mediated presynaptic inhibition is not known. Here, simultaneous recordings from a giant presynaptic terminal, the calyx of Held, and its(More)
Voltage-gated calcium channels are well characterized at neuronal somata but less thoroughly understood at the presynaptic terminal where they trigger transmitter release. In order to elucidate how the intrinsic properties of presynaptic calcium channels influence synaptic function, we have made direct recordings of the presynaptic calcium current (I(pCa))(More)
1. An in vitro brainstem slice preparation of the superior olivary complex has been developed permitting patch recording from a presynaptic terminal (calyx of Held) and from its postsynaptic target--the principal neurone of the medial nucleus of the trapezoid body (MNTB). 2. The fluorescent stain DiI (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine(More)
1. Using a combination of patch-clamp, in situ hybridization and computer simulation techniques, we have analysed the contribution of potassium channels to the ability of a subset of mouse auditory neurones to fire at high frequencies. 2. Voltage-clamp recordings from the principal neurones of the medial nucleus of the trapezoid body (MNTB) revealed a(More)
Low-threshold voltage-gated potassium currents (I(LT)) activating close to resting membrane potentials play an important role in shaping action potential (AP) firing patterns. In the medial nucleus of the trapezoid body (MNTB), I(LT) ensures generation of single APs during each EPSP, so that the timing and pattern of AP firing is preserved on transmission(More)
The medial nucleus of the trapezoid body (MNTB) relays auditory information important for sound source localization. MNTB neurons faithfully preserve the temporal patterning of action potentials (APs) occurring in their single giant input synapse, even at high frequencies. The aim of this work was to examine the postsynaptic potassium conductances that(More)
1. The presynaptic calcium current (IpCa) was recorded from the calyx of Held in rat brainstem slices using the whole-cell patch clamp technique. 2. Tetanic activation of IpCa by 1 ms depolarizing voltage steps markedly enhanced the amplitude of IpCa. Using a paired pulse protocol, the second (test) response was facilitated with inter-pulse intervals of(More)
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. Whole-cell patch recordings were used to examine the EPSC generated by the calyx of Held in neurones of the medial nucleus of the trapezoid body (MNTB). Each neurone receives a somatic input from a single calyx (giant synapse). 2. A slow NMDA receptor-mediated EPSC peaked in 10 ms and decayed as a double exponential with time constants of 44 and 147 ms.(More)
Beyond their role in generating ATP, mitochondria have a high capacity to sequester calcium. The interdependence of these functions and limited access to presynaptic compartments makes it difficult to assess the role of sequestration in synaptic transmission. We addressed this important question using the calyx of Held as a model glutamatergic synapse by(More)