Biology
A brain's neural network is made up of specialized cells called neurons that are interconnected at points called synapses. Electrical signals travel from one neuron and its axon across a synapse to another neuron's dendritic spine. Each neuron is interconnected with thousands of other neurons, and it is the pattern and relative strength of these connections that experts believe form the basis of learning, memory and behavior. When new learning, memory or behavior occurs, synapses are created and/or the strength of existing synapses modified.
Dendritic spines, a critical component required for proper synapse function, are specialized protrusions found on neurons that undergo significant morphological changes when the strength of an existing synapse is modulated, a new synapse is formed, or an existing synapse is eliminated. The ability of dendritic spines to rapidly change shape (plasticity) into the correct form in response to an appropriate stimulus directly controls the strength and function of synaptic connections and is tightly regulated.
Changes in dendritic spine morphology have been shown to directly impact higher brain functions including learning, memory and behavior. Abnormal dendritic spine morphology is observed in many neurologic disorders that are accompanied by cognitive deficits. This suggests that spine morphology is closely associated with synapse function, and that abnormal spine morphology is at the root of the neurological symptoms of these disorders.
Biology