Previous histological and immunocytochemical studies suggest that reorganization of the dentate granule cell axons, the mossy fibers, can occur in epileptic human hippocampus (Sutula et al., 1989; Houser et al., 1990; Babb et al., 1991) and in animal models of epilepsy (Tauck and Nadler, 1985; Sutula et al., 1988; Cronin et al., 1992). However, neuroanatomical analyses of the trajectory and mor...

Models for generating repetitive impulse activity were developed based on multicompartmental representations of ganglion cell morphology in the amphibian retina. Each model includes five nonlinear ion channels and one linear (leakage) channel. Compartmental distribution of ion channel type and density was designed to simulate whole cell recording experiments carried out in the intact retina-eye...

Nerve impulse entrainment and other excitation and passive phenomena are analyzed for a morphologically diverse and exhaustive data set (n = 57) of realistic (3-dimensional computer traced) soma-dendritic tree structures of ganglion cells in the tiger salamander (Ambystoma tigrinum) retina. The neurons, including axon and an anatomically specialized thin axonal segment that is observed in every...

Cerebral peptide 2 (CP2), a 41 amino acid neuropeptide, was identified because it was transported from the cerebral ganglia of Aplysia to other central ganglia. Immunocytology indicates that CP2 is distributed widely in the CNS and peripheral tissues of Aplysia. Most CP2-immunoreactive neurons were found in the cerebral ganglia and extensively overlap with the distribution of cerebral peptide 1...

PERSPECTIVES After injury, damaged axons have the capacity to regenerate, but the regenerative capacity of the axon, particularly axons of the central nervous system, is quite limited. This is because the damaged axons tend to retract, because they encounter obstacles such as scar tissue and inhibitory molecules, and because their growth rates simply do not match those of a juvenile axon. In re...

mark where postsynaptic spiking was concerned. Perhaps the most quoted idea in the history of neurosci-The Last Laugh ence is the synaptic modification postulate proposed Recently, an exciting set of experiments have caused by the Canadian psychologist Donald Hebb in his 1949 renewed interest in postsynaptic spiking and synaptic book, The Organization of Behavior. Formulated to ex-plasticity an...

Synaptic contacts located on the axon hillock and the initial axon segment of pyramidal neurons have been observed already by Palay et al. 9 and have been described in more detail by Peters et al.lO. Nothing, so far, is known about the origin and possible significance of these axo-axonic contacts. More recently we have come across a specific type of interneuron in the visual cortex of the rat t...

In this issue of The EMBO Journal, Li et al (2011) show that the axon initial segment (AIS) functions as a retrograde trafficking barrier, or axonal rectifier, to exclude axonal Tau from re-entry into the somatodendritic compartment. They elucidate the molecular basis of this rectification by showing that hyperphosphorylation of Tau permits it to detach from microtubules (MTs) and bypass the re...

Acute renal failure is one of the hallmarks of the hemolytic uremic syndrome (HUS). Infection with a verocytotoxin (VT)- or Shiga-like toxin (SLT)-producing Escherichia coli has been strongly implicated in the etiology of the epidemic form of HUS. The functional receptor for these closely related toxins appears to be a glycosphingolipid, globotriaosylceramide (Gb3). Endothelial damage in the gl...

1. Nongated ion channels establish the resting membrane potential of neurons; voltage-gated ion channels are responsible for the action potential and the release of neurotransmitter. 2. Ligand-gated ion channels cause membrane depolarization or hyperpolarization in response to neurotransmitter. 3. Nongated ion channels are distributed throughout the neuronal membrane; voltage-gated channels are...