Presynaptic Black Box Opened by Pioneers at Biophysics Department in University College London

The mechanism of chemical synaptic transmission was elucidated at the frog neuromuscular junction (NMJ) and at the squid giant synapse by Katz, Miledi and other researchers. Later progress in molecular biology revealed numerous types of proteins in mammalian central synapses. To establish molecular-functional correlation in synaptic transmission, it now seems essential to re-address the fundamental mechanisms at mammalian central synapses. Using patch-clamp whole-cell recording at the calyx of Held in slices of rodent brainstem, we have identified quantal EPSCs and reproduced the quantal analysis established at the NMJ. Intra-terminal whole-cell loading of the neurotransmitter, glutamate, revealed that vesicular transmitter content is an important determinant of quantal size and its variation. Regarding the Ca(2+)-dependence of transmitter release, the average coupling distance between Ca(2+) entry sites and exocytic vesicles was estimated as tens of nanometers and was found to undergo developmental tightening at the calyx of Held. Numerical simulations suggested that this distance can determine the synaptic delay, synchronicity of vesicular transmitter release, and release probability. The super-linear input (presynaptic)-output (postsynaptic) relationship of neurotransmission is an important physiological feature discovered at squid giant synapses. However, at the calyx of Held, unlike at the squid synapse, the input-output relationship had a wide safety margin, protecting transmitter release from a diminishment of presynaptic action potentials. As in the NMJ, Ca(2+) remaining in the cytosol after action potential facilitates subsequent release. As a downstream mechanism of this residual Ca(2+), a Ca(2+)-induced Ca(2+) channel activation via high-affinity Ca(2+) binding proteins was discovered at mammalian central synapses

Radiological Issues for Fukushima’s Revitalized Future

Effects of Radiation / Radiation Protectio

Problems of Present Tsunami Disaster Reduction Measure Shown by The Great East Japan Earthquake

特集　東日本大震

First record of the terrestrial amphipod, Talitroides alluaudi (Chevreux, 1896) (Crustacea, Amphipoda, Brevitalitridae), from Japan

We report Talitroides alluaudi (Chevreux, 1896) from Miyako Island, Ryukyu Islands, Japan. Although this terrestrial amphipod is distributed worldwide, including Indo-Pacific islands, Europe, and North and South America, the present specimens represent the first record of this species from Japanese islands. The cytochrome c oxidase subunit I (COI) sequence of a Miyako Island specimen was unique compared with the known COI sequences from Taiwanese and Bermudan populations