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Because all brain areas are bidirectionally coupled, these connections between brain areas form feedback loops. Positive feedback loops tend to cause oscillatory activity where frequency is inversely related to the delay time. An example of such a feedback loop is the connections between the thalamus and cortex – the thalamocortical radiations.
HCN4 is the main isoform expressed in the sinoatrial node, but low levels of HCN1 and HCN2 have also been reported.The current through HCN channels, called the pacemaker current (I f), plays a key role in the generation and modulation of cardiac rhythmicity, [13] as they are responsible for the spontaneous depolarization in pacemaker action potentials in the heart.
Brainwave entrainment, also referred to as brainwave synchronization or neural entrainment, refers to the observation that brainwaves (large-scale electrical oscillations in the brain) will naturally synchronize to the rhythm of periodic external stimuli, such as flickering lights, [1] speech, [2] music, [3] or tactile stimuli.
Electrical synapses allow for faster transmission because they do not require the slow diffusion of neurotransmitters across the synaptic cleft. Hence, electrical synapses are used whenever fast response and coordination of timing are crucial, as in escape reflexes, the retina of vertebrates, and the heart.
For example, a doctor may insert a catheter containing an electrode into the heart to record the heart muscle's electrical activity. Another example of clinical electrophysiology is clinical neurophysiology. In this medical specialty, doctors measure the electrical properties of the brain, spinal cord, and nerves.
Synchronized neuronal currents induce weak magnetic fields. The brain's magnetic field, measuring at 10 femto tesla (fT) for cortical activity and 10 3 fT for the human alpha rhythm, is considerably smaller than the ambient magnetic noise in an urban environment, which is on the order of 10 8 fT or 0.1 μT.
The cardiac pacemaker is the heart's natural rhythm generator. It employs pacemaker cells that generate electrical impulses, known as cardiac action potentials.These potentials cause the cardiac muscle to contract, and the rate of which these muscles contract determines the heart rate.
hERG (the human Ether-à-go-go-Related Gene) is a gene that codes for a protein known as K v 11.1, the alpha subunit of a potassium ion channel.This ion channel (sometimes simply denoted as 'hERG') is best known for its contribution to the electrical activity of the heart: the hERG channel mediates the repolarizing I Kr current in the cardiac action potential, which helps coordinate the heart ...