mercy killing

a direct action intended to end what would otherwise be the prolonged agony of a dying person or animal. The concept has been known since ancient times: Warriors often were expected to kill a desperately wounded comrade or enemy. Severely injured animals are also put out of their misery by mercy killing. See also assisted death; euthanasia.

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Psychology term of the day

September 8th 2024

NMDA receptor

a type of glutamate receptor that binds NMDA as well as glutamate. NMDA receptors are coupled to ligand-gated ion channels and are also voltage-sensitive, which enables them to participate in a variety of information-processing operations at synapses where glutamate is the neurotransmitter. The drugs of abuse ketamine and PCP are antagonists at NMDA receptors, preventing the influx of calcium ions at calcium channels, which may cause the hallucinogenic effects of these drugs. Excessive flow of calcium ions into the presynaptic neuron via the NMDA receptor is thought to contribute to glutamate toxicity. A hypothesis on the etiology of schizophrenia involves dysfunction of the NMDA glutamate receptor (see glutamate hypothesis). Compare AMPA receptor.