<span>If a nurse notices that an accident victim cannot clench his teeth, there is a good chance that his trigeminal nerve has been affected. This nerve is located inside the brain and its primary purpose is to transmit sensations from a person's face to the brain. Damage to this nerve could cause the patient to be unable to clench their teeth.</span>
Long-term potentiation (LTP) is considered a cellular correlate of learning and memory. The presence of G protein-activated inwardly rectifying K(+) (GIRK) channels near excitatory synapses on dendritic spines suggests their possible involvement in synaptic plasticity. However, whether activity-dependent regulation of channels affects excitatory synaptic plasticity is unknown. In a companion article we have reported activity-dependent regulation of GIRK channel density in cultured hippocampal neurons that requires activity oF receptors (NMDAR) and protein phosphatase-1 (PP1) and takes place within 15 min. In this study, we performed whole-cell recordings of cultured hippocampal neurons and found that NMDAR activation increases basal GIRK current and GIRK channel activation mediated by adenosine A(1) receptors, but not GABA(B) receptors. Given the similar involvement of NMDARs, adenosine receptors, and PP1 in depotentiation of LTP caused by low-frequency stimulation that immediately follows LTP-inducing high-frequency stimulation, we wondered whether NMDAR-induced increase in GIRK channel surface density and current may contribute to the molecular mechanisms underlying this specific depotentiation. Remarkably, GIRK2 null mutation or GIRK channel blockade abolishes depotentiation of LTP, demonstrating that GIRK channels are critical for depotentiation, one form of excitatory synaptic plasticity.
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This skin is known as the body membrane
External respiration (correct answer) involves the exchange of oxygen and carbon dioxide within the environment.
The exchange of wastes through the skin is just called excretion by sweating.
There is no exchange of nutrients that occur in the lungs but rather absorption of nutrients is the function of the gastrointestinal tract.
The exchange of oxygen and carbon dioxide within the cell is called cellular respiration and involves carrying oxygen from the blood to the cell then the cell uses it as the final electron acceptor in the electron transport chain. The metabolic wastes of the cell, primarily carbon dioxide, goes now to the bloodstream to be exchanged for oxygen in the lungs.