The relationship between calcium conductances and developmental changes in the active and passive membrane properties of cerebellar Purkinje neurons from rats was studied in a culture model system by using current-clamp and voltage-clamp techniques. These cultures, at 6-21 d of age, represented the main period of morphological and physiological development of the Purkinje neuron. In the current...

Theoretical studies have shown that calcium influx through N-methyl-D-aspartate (NMDA) receptors is a sufficient signal to account for various induction protocols of bidirectional synaptic plasticity, including spike time-dependent plasticity (STDP). The STDP curves obtained by these different models exhibits a form of spike time-dependent long-term depression that occurs when a presynaptic spi...

The bag cell neurons of Aplysia are a cluster of cells that control egg laying behavior. After brief synaptic stimulation, they depolarize and fire spontaneously for up to 30 min. During the first few seconds of this afterdischarge, the action potentials of the bag cell neurons undergo pronounced broadening. Single bag cell neurons in culture also show spike broadening in response to repeated d...

Calcium responses have been observed as spikes of the whole-cell calcium concentration in numerous cell types and are essential for translating extracellular stimuli into cellular responses. While there are several suggestions for how this encoding is achieved, we still lack a comprehensive theory. To achieve this goal it is necessary to reliably predict the temporal evolution of calcium spike ...

The effects of external calcium deprivation on certain characteristics of the action potential of the lobster motor axon have been studied. Upon exposure to calcium-free solution the spike amplitude is rapidly decreased within a few minutes and is followed by a slow linear decline. The rates of spike rise and fall are proportionally reduced more than the spike but follow similar time courses du...

Two-photon calcium imaging enables functional analysis of neuronal circuits by inferring action potential (AP) occurrence ("spike trains") from cellular fluorescence signals. It remains unclear how experimental parameters such as signal-to-noise ratio (SNR) and acquisition rate affect spike inference and whether additional information about network structure can be extracted. Here we present a ...

Many cell types show repetitive short lasting cytosolic calcium spikes with long interspike periods when stimulated with submaximal concentrations of agonists linked to the phosphoinositide signaling pathway. In pancreatic acinar cells these spikes have been shown to be evoked by constant levels of inositol trisphosphate through a mechanism of calcium-induced calcium release and do not depend a...

Investigations concerning the ionic basis of the action potential in nerve and muscle have revealed a variety of mechanisms ranging from total dependence on sodium, first described quantitatively in the squid axon (Hodgkin & Huxley, 1952), to total dependence on calcium in crustacean muscles (Fatt & Ginsborg, 1958; Abbott & Parnas, 1965; Hagiwara & Naka, 1964; Hagiwara & Nakajima, 1966). Betwee...

Long-term modification of synaptic strength is one of the basic mechanisms of memory formation and activity-dependent refinement of neural circuits. This idea was purposed by Hebb to provide a basis for the formation of a cell assembly. Repetitive correlated activity of pre-synaptic and post-synaptic neurons can induce long-lasting synaptic strength modification, the direction and extent of whi...