dendritic spines

den·drit·ic spines

variably long excrescences of nerve cell dendrites, varying in shape from small knobs to thornlike or filamentous processes, usually more numerous on distal dendrite arborizations than on the proximal part of dendritic trunks. Dentritic spines are a preferential site of synaptic axodendritic contact; they are sparse or absent in some types of nerve cells (motor neurons, the large cells of the globus pallidus, and stellate cells of the cerebral cortex), and exceedingly numerous in others such as the pyramidal cells of the cerebral cortex and the Purkinje cells of the cerebellar cortex.
Synonym(s): dendritic thorns, gemmule (2)

den·drit·ic spines

(den-drit'ik spīnz)
Variably long excrescences of nerve cell dendrites, varying in shape from small knobs to thornlike or filamentous processes, usually more numerous on distal dendrite arborizations than on the proximal part of dendritic trunks; they are a preferential site of synaptic axodendritic contact; sparse or absent in some types of nerve cells (motor neurons, the large cells of the globus pallidus, stellate cells of the cerebral cortex), exceedingly numerous in others such as the pyramidal cells of the cerebral cortex and the Purkinje cells of the cerebellar cortex.
Synonym(s): gemmule (2) .
References in periodicals archive ?
The bundles are the supporting skeletons of dendritic spines, which are the spiky protrusions that receive chemical messages through synapses from other neurons.
Researchers discovered that when this gene is activated by short bursts of exercise, it promotes small growths on neurons known as dendritic spines -- the site at which synapses form.
In the mammalian cerebral cortex, approximately 80% of excitatory axodendritic synapses are formed on the small protrusions of a neuron's dendrite (dendritic spines).
Additionally, NV-5138 was also observed to increase the number and function of dendritic spines indicating changes in synaptic morphology in neurons comprising the portion of the brain known to be involved in the maintenance of mood.
Membrane trafficking from intracellular compartments is shown to be essential for maintenance of dendritic spines, sites for more than ninety percent of excitatory synapses in mammalian brain.
Pre-clinical studies have shown that chronic treatment with Bryostatin-1 rescues young Fragile X mice from the disorder phenotypes, including normalization of most Fragile X abnormalities in: 1) hippocampal brain-derived neurotrophic factor expression; 2) postsynaptic density-95 levels; 3) transformation of immature dendritic spines to mature synapses; 4) densities of the presynaptic and postsynaptic membranes, and; 5) spatial learning and memory.
Joel Soler, the lead author of the study and a doctoral graduate student at the university, explained this happened because of a causal link between the intensity of light and two things, one called the brain derived neurotrophic factor and the other called dendritic spines. BDNF is a peptide (a short chain of amino acids, essentially protein) responsible for maintaining healthy neurons and connections in the hippocampus and the spines allow the neurons to connect to each other.
In fact, the adult brain is structurally dynamic [35-37], dendritic spines dynamically turn over in the adult brain [37, 38], and learning novel tasks are associated with a further increase in spine turnover [38].
Without sufficient sleep, the dendritic spines that receive signals sent by one brain cell to another were reduced in density and length in a specific region of the hippocampus, restricting the animals' ability to consolidate memories.
Changes within the synapse associated with epilepsy are exerted in dendritic spines [38].
To analyze the changes in the morphology of the dendritic spines in hippocampus, the Golgi-Cox staining was applied with minor modification as described by Hu et al.