dendriittipiikkejä

Dendriittipiikkejä, also known as dendritic spines, are small protrusions from the dendrites of neurons that serve as the primary site for receiving most excitatory synaptic inputs. These specialized structures are highly dynamic and play a crucial role in learning and memory. Their morphology and density can change rapidly in response to neural activity, reflecting the plasticity of synaptic connections.

The shape and size of dendritic spines vary, and these differences are thought to correlate with synaptic strength and function. Typically, a spine consists of a head and a neck. The head is the postsynaptic compartment, containing receptors for neurotransmitters, while the neck connects the head to the main dendritic shaft. The spine apparatus, a specialized endoplasmic reticulum within the spine, is involved in calcium homeostasis and protein synthesis, both vital for synaptic plasticity.

The formation, stabilization, and elimination of dendritic spines are key mechanisms underlying synaptic plasticity. Long-term potentiation (LTP), a cellular model of learning, is often associated with an increase in spine head volume and enhanced synaptic transmission. Conversely, long-term depression (LTD), which weakens synaptic connections, can lead to spine shrinkage or elimination. Disruptions in dendritic spine morphology and dynamics have been implicated in various neurological and psychiatric disorders, including intellectual disability, autism spectrum disorder, and schizophrenia. Research into dendritic spines continues to be a rapidly evolving field, offering insights into the fundamental processes of brain function and dysfunction.