The role of the<unk>  has been implicated in a clinical context, namely in the functioning of the nervous system itself as well as in the cardiovascular system. Febrile seizures A febrile seizure, or "fever fit", is a convulsion associated with a significant rise in body temperature, occurring most commonly in early childhood. Repeated episodes of childhood febrile seizures are associated with an increased risk of temporal lobe epilepsy in adulthood. With patch clamp recording, an analogous state was replicated in vitro in rat cortical neurons after induction of febrile body temperatures; a notable decrease in<unk>  was observed. The mechanism for this decrease possibly involves suppression of inhibition mediated by the GABAB receptor with excessive heat exposure. ALS and diabetes Abnormalities in neuronal excitability have been noted in amyotrophic lateral sclerosis and diabetes patients. While the mechanism ultimately responsible for the variance differs between the two conditions, tests through a response to ischemia indicate a similar resistance, ironically, to ischemia and resulting paresthesias. As ischemia occurs through inhibition of the sodium-potassium pump, abnormalities in the<unk>  are hence implicated. Arrythmia Since the 1940s, the concept of diastolic depolarization, or "pacemaker<unk> ", has become established; this mechanism is a characteristic distinctive of cardiac tissue. When the<unk>  is reached and the resulting action<unk>  fires, a heartbeat results from the interactions; however, when this heartbeat occurs at an irregular time, a<unk> ly serious condition known as arrythmia may result. Use of medications A variety of drugs can present prolongation of the QT interval as a side effect. Prolongation of this interval is a result of a delay in sodium and calcium channel inactivation; without proper channel inactivation, the<unk>  is reached prematurely and thus arrhythmia tends to result. These drugs, known as pro-arrhythmic agents, include antimicrobials, antipsychotics, methadone, and, ironically, antiarrhythmic agents. The use of such agents is particularly frequent in intensive care units, and special care must be exercised when QT intervals are prolonged in such patients: arrhythmias as a result of prolonged QT intervals include the<unk> ly fatal torsades de pointes, or TdP. Role of diet Diet may be a variable in the risk of arrhythmia. Polyunsaturated fatty acids, found in fish oils and several plant oils, serve a role in the prevention of arrhythmias. By inhibiting the voltage-dependent sodium current, these oils shift the<unk>  to a more positive value; therefore, an action<unk>  requires increased depolarization. Clinically therapeutic use of these extracts remains a subject of research, but a strong correlation is established between regular consumption of fish oil and lower frequency of hospitalization for atrial fibrillation, a severe and increasingly common arrythmia.
Threshold potential
End-plate potential
Dark adaptation threshold
Intermuscular coherence
Threshold of pain
Frequency following response
Extraction ratio
Peak kilovoltage