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.
The BDNF effects on dendritic spines
of mature hippocampal neurons depend on neuronal activity.
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 .
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
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.