Taugafrumu

Taugafrumu, the Icelandic term for neuron, is the basic signaling cell of the nervous system. Neurons are specialized for receiving, processing, and transmitting information through electrical impulses and chemical signals, and they operate within networks that include glial cells for support.

Most taugafrumur have three main regions: soma (cell body), dendrites, and an axon. Dendrites receive inputs; the soma integrates signals; the axon conducts impulses to synapses. Axons may be insulated by myelin (produced by oligodendrocytes in the CNS and Schwann cells in the PNS), with nodes of Ranvier enhancing conduction.

Action potentials arise via voltage-gated ion channels, propagating along the axon and triggering neurotransmitter release at synapses. Neurotransmitters cross the synaptic cleft to influence postsynaptic receptors, producing excitatory or inhibitory effects on downstream neurons.

Neurons are classified by function (sensory, motor, interneurons) or by morphology (multipolar, bipolar, unipolar). They can also be grouped by predominant transmitter (glutamatergic, GABAergic, cholinergic, among others).

Neurons originate from neural progenitor cells during development. Adult neurogenesis occurs in restricted brain regions, such as the hippocampus. Peripheral nerves can regenerate after injury, aided by Schwann cells, while central nervous system regeneration is limited by inhibitory environments.

Neuronal networks exhibit synaptic plasticity, including long-term potentiation and depression, which support learning and memory and adaptation to experience.