Dendritic spines are actin-rich protrusions that establish excitatory synaptic contacts with surrounding neurons. Reorganization of the actin cytoskeleton is critical for the development and plasticity of dendritic spines, which is the basis for learning and memory. Rho family GTPases are emerging as important modulators of spines and synapses, predominantly through their ability to regulate ac...

It is well known that predators can induce morphological changes in some fish: individuals exposed to predation cues increase body depth and the length of spines. We hypothesize that these structures may evolve synergistically, as together, these traits will further enlarge the body dimensions of the fish that gape-limited predators must overcome. We therefore expect that the orientation of the...

An area of the caudal forebrain of male zebra finches, the Archi-Neostriatum caudale (ANC), which is active during arousal (Bischof & Herrmann, 1986, 1988), shows rearing-dependent changes in neuron morphology (Rollenhagen & Bischof, 1991). We demonstrate here that rearing conditions also affect the shape of spines of one of the four ANC neuron types. This neuron type was examined in birds rear...

A 12 year-old Chinese schoolgirl presented with left-sided scoliosis at the age of 9 years. She has a rare defect in lipid metabolism, which is not known to be associated with spinal deformity. Her scoliotic curve deteriorated despite bracing. We report a rare occurrence of scoliosis in patient with lipodystrophy and the difficulty of using instrumented fusion in treating this condition.

Scoliosis is a twisting deformation of the spine, including all the related anatomical structures (bones, muscles, ligaments, organs). It is essentially three-dimensional, non reducible and progressive, opposite to “scoliotic attitudes” which are simple compensatory deviation in the frontal plane to lower leg asymmetry, or to secondary deformities corrected after resolving of the cause (infecti...

The ability to monitor ongoing changes in the shape of dendritic spines has important implications for the understanding of the functional correlates of the great variety of shapes and sizes of dendritic spines in central neurons. We have monitored and three-dimensionally reconstructed dendritic spines in cultured hippocampal neurons over several hours of observation in a confocal laser scannin...

The somatosensory barrel cortex of rodents and its afferent pathway from the facial vibrissae is a very useful model for studying neuronal plasticity. Dendritic spines are the most labile elements of synaptic circuitry and the most likely substrate of experience-dependent alterations in neuronal circuits in cerebral cortex. We characterized morphologically and numerically a specific population ...

Ca 2 influx through synaptic NMDA receptors (NMDA-Rs) triggers a variety of adaptive cellular processes. To probe NMDA-R-mediated [Ca 2 ] signaling, we used two-photon glutamate uncaging to stimulate NMDA-Rs on individual dendritic spines of CA1 pyramidal neurons in rat brain slices. We measured NMDA-R currents at the soma and NMDA-R-mediated [Ca 2 ] transients in stimulated spines ( [Ca 2 ]). ...

Dendritic spines receive most excitatory inputs in the CNS and compartmentalize calcium. Although the mechanisms of calcium influx into spines have been explored, it is unknown what determines the calcium decay kinetics in spines. With two-photon microscopy we investigate action potential-induced calcium dynamics in spines from rat CA1 pyramidal neurons in slices. The [Ca(2+)](i) in most spines...

Cofilin and other Actin-regulating proteins are essential in regulating the shape of dendritic spines, which are sites of neuronal communications in the brain, and their malfunctions are implicated in neurodegeneration related to aging. The analysis of cofilin motility in dendritic spines using fluorescence video-microscopy may allow for the discovery of its effects on synaptic functions. To da...