Short-term synaptic depression is an important component of computation within neural networks, but little is known of its contribution to information processing during synaptically generated spike trains. We analyzed short-term synaptic depression at a synapse between two identified motoneurons innervating the hind leg of the locust: the FETi-FlTi synapse (fast extensor tibiae-flexor tibiae). ...

Calcium imaging using fluorescent reporters is the most widely used optical approach to investigate activity in intact neuronal circuits with single-cell resolution. Calcium signals, however, are often difficult to interpret, especially if the desired output quantity is membrane voltage or instantaneous firing rates. Combining dendritic intracellular electrophysiology and multi-photon calcium i...

BACKGROUND The conversion of an analog stimulus into the digital form of spikes is a fundamental step in encoding sensory information. Here, we investigate this transformation in the visual system of fish by in vivo calcium imaging and electrophysiology of retinal bipolar cells, which have been assumed to be purely graded neurons. RESULTS Synapses of all major classes of retinal bipolar cell ...

We introduce a novel computational model of hippocampal pyramidal cells physiology based on an up-to-date, detailed description of passive and active biophysical properties and real dendritic morphology. This model constitutes a modification of a previous (1995) model which included complex calcium dynamics and Na(+), K(+), and Ca(2+) currents. Changes reflect recently acquired experimental kno...

In the cerebellum, the parallel fiber-Purkinje cell synapse can undergo long-term synaptic plasticity suggested to underlie motor learning and resulting from variations in intracellular calcium concentration ([Ca2+]i). Ca2+ binding proteins are enriched in the cerebellum, but their role in information processing is not clear. Here, we show that mice deficient in calretinin (Cr-/-) are impaired ...

In a variety of cell types extracellular hormonal stimuli varying in time are transfered across the cell membrane into repetitive spikes of the intracellular calcium concentration ([Ca2+]i). Distinct temporal patterns of [Ca2+]i spikes are capable of regulating the function and structure of target cells. Here, we investigate the ability of transmembrane signaling to encode time-varying hormonal...

We use a multi-compartmental model of a CA1 pyramidal cell to study changes in hippocampal excitability that result from aging-induced alterations in calcium-dependent membrane mechanisms. The model incorporates Nand L-type calcium channels which are respectively coupled to fast and slow afterhyperpolarization potassium channels. Model parameters are calibrated using physiological data. Compute...

Sasaki T, Takahashi N, Matsuki N, Ikegaya Y. Fast and accurate detection of action potentials from somatic calcium fluctuations. J Neurophysiol 100: 1668–1676, 2008. First published July 2, 2008; doi:10.1152/jn.00084.2008. Large-scale recording from a population of neurons is a promising strategy for approaching the study of complex brain functions. Taking advantage of the fact that action pote...