@article{3804,
abstract = {Kv3 channels are thought to be essential for the fast-spiking (FS) phenotype in GABAergic interneurons, but how these channels confer the ability to generate action potentials (APs) at high frequency is unknown. To address this question, we developed a fast dynamic-clamp system (approximately 50 kHz) that allowed us to add a Kv3 model conductance to CA1 oriens alveus (OA) interneurons in hippocampal slices. Selective pharmacological block of Kv3 channels by 0.3 mm 4-aminopyridine or 1 mm tetraethylammonium ions led to a marked broadening of APs during trains of short stimuli and a reduction in AP frequency during 1 sec stimuli. The addition of artificial Kv3 conductance restored the original AP pattern. Subtraction of Kv3 conductance by dynamic clamp mimicked the effects of the blockers. Application of artificial Kv3 conductance also led to FS in OA interneurons after complete K+ channel block and even induced FS in hippocampal pyramidal neurons in the absence of blockers. Adding artificial Kv3 conductance with altered deactivation kinetics revealed a nonmonotonic relationship between mean AP frequency and deactivation rate, with a maximum slightly above the original value. Insertion of artificial Kv3 conductance with either lowered activation threshold or inactivation also led to a reduction in the mean AP frequency. However, the mechanisms were distinct. Shifting the activation threshold induced adaptation, whereas adding inactivation caused frequency-dependent AP broadening. In conclusion, Kv3 channels are necessary for the FS phenotype of OA interneurons, and several of their gating properties appear to be optimized for high-frequency repetitive activity.},
author = {Lien, Cheng-Chang and Peter Jonas},
journal = {Journal of Neuroscience},
number = {6},
pages = {2058 -- 68},
publisher = {Society for Neuroscience},
title = {{Kv3 potassium conductance is necessary and kinetically optimized for high-frequency action potential generation in hippocampal interneurons}},
volume = {23},
year = {2003},
}
@article{3806,
abstract = {To probe exocytosis at a cortical glutamatergic synapse, we made capacitance measurements in whole-cell recorded hippocampal mossy fiber terminals. Evaluation of different methods by using a morphology-based equivalent electrical model revealed that quantitative capacitance measurements are possible in this presynaptic structure. Voltage pulses leading to presynaptic Ca2+ inflow evoked large capacitance signals that showed saturation with increasing pulse duration. The mean peak capacitance increase was 100 fF, corresponding to a pool of approximately 1,400 releasable vesicles. Thus hippocampal mossy fiber synapses have a vesicular "maxipool." Large pool size and rapid vesicle recycling may underlie the uniquely large extent of activity-dependent plasticity in this synapse.},
author = {Hallermann, Stefan and Pawlu, Christian and Peter Jonas and Heckmann, Manfred},
journal = {PNAS},
number = {15},
pages = {8975 -- 80},
publisher = {National Academy of Sciences},
title = {{A large pool of releasable vesicles in a cortical glutamatergic synapse}},
doi = {10.1073/pnas.1432836100},
volume = {100},
year = {2003},
}
@inproceedings{3897,
abstract = {Many verification, planning, and control problems can be modeled as games played on state-transition graphs by one or two players whose conflicting goals are to form a path in the graph. The focus here is on simple stochastic parity games, that is, two-player games with turn-based probabilistic transitions and omega-regular objectives formalized as parity (Rabin chain) winning conditions. An efficient translation from simple stochastic parity games to nonstochastic parity games is given. As many algorithms are known for solving the latter, the translation yields efficient algorithms for computing the states of a simple stochastic parity game from which a player can win with probability 1. An important special case of simple stochastic parity games are the Markov decision processes with Buchi objectives. For this special case a first provably subquadratic algorithm is given for computing the states from which the single player has a strategy to achieve a Buchi objective with probability 1. For game graphs with m edges the algorithm works in time O(mrootm). Interestingly, a similar technique sheds light on the question of the computational complexity of solving simple Buchi games and yields the first provably subquadratic algorithm, with a running time of O(n(2)/log n) for game graphs with n vertices and O(n) edges.},
author = {Krishnendu Chatterjee and JurdziĆski, Marcin and Thomas Henzinger},
pages = {100 -- 113},
publisher = {Springer},
title = {{Simple stochastic parity games}},
doi = {10.1007/978-3-540-45220-1_11},
volume = {2803},
year = {2003},
}
@inproceedings{3898,
abstract = {We study the problem of determining stack boundedness and the exact maximum stack size for three classes of interrupt-driven programs. Interrupt-driven programs axe used in many real-time applications that require responsive interrupt handling. In order to ensure responsiveness, programmers often enable interrupt processing in the body of lower-priority interrupt handlers. In such programs a programming error can allow interrupt handlers to be interrupted in cyclic fashion to lead to an unbounded stack, causing the system to crash. For a restricted class of interrupt-driven programs, we show that there is a polynomial-time procedure to check stack boundedness, while determining the exact maximum stack size is PSPACE-complete. For a larger class of programs, the two problems are both PSPACE-complete, and for the largest class of programs we consider, the two problems are PSPACE-hard and can be solved in exponential time.},
author = {Krishnendu Chatterjee and Ma, Di and Majumdar, Ritankar S and Zhao, Tian and Thomas Henzinger and Palsberg, Jens},
pages = {109 -- 126},
publisher = {Springer},
title = {{Stack size analysis for interrupt-driven programs}},
doi = {10.1007/3-540-44898-5_7},
volume = {2694},
year = {2003},
}