Search results
Results from the WOW.Com Content Network
[3] [5] Twin studies show its pattern is largely genetically determined since there is a heritability of 0.40 for the mean cortisol increase after awakening and 0.48 for the area under the cortisol rise curve. [6] Normally, the highest cortisol secretion happens in the second half of the night with peak cortisol production occurring in the ...
Another may be a conductance-based neuron model that views neurons as points and describes the membrane voltage dynamics as a function of trans-membrane currents. A mathematically simpler "integrate-and-fire" model significantly simplifies the description of ion channel and membrane potential dynamics (initially studied by Lapique in 1907). [5] [6]
The third state equation: = [()], allows a great variety of dynamic behaviors of the membrane potential, described by variable x, including unpredictable behavior, which is referred to as chaotic dynamics. This makes the Hindmarsh–Rose model relatively simple and provides a good qualitative description of the many different patterns that are ...
In 1973, M. M. Taylor [1] suggested that if synapses were strengthened for which a presynaptic spike occurred just before a postsynaptic spike more often than the reverse (Hebbian learning), while with the opposite timing or in the absence of a closely timed presynaptic spike, synapses were weakened (anti-Hebbian learning), the result would be an informationally efficient recoding of input ...
The temporal structure of a spike train or firing rate evoked by a stimulus is determined both by the dynamics of the stimulus and by the nature of the neural encoding process. Stimuli that change rapidly tend to generate precisely timed spikes [28] (and rapidly changing firing rates in PSTHs) no matter what neural coding strategy is being used ...
The biologically inspired Hodgkin–Huxley model of a spiking neuron was proposed in 1952. This model describes how action potentials are initiated and propagated. . Communication between neurons, which requires the exchange of chemical neurotransmitters in the synaptic gap, is described in various models, such as the integrate-and-fire model, FitzHugh–Nagumo model (1961–1962), and ...
The spike response model (SRM) [1] is a spiking neuron model in which spikes are generated by either a deterministic [2] or a stochastic [1] threshold process. In the SRM, the membrane voltage V is described as a linear sum of the postsynaptic potentials (PSPs) caused by spike arrivals to which the effects of refractoriness and adaptation are added.
11-Deoxycortisol in mammals has limited glucocorticoid activity, but it is the direct precursor of the major mammalian glucocorticoid, cortisol. [15] As a result, the level of 11-deoxycortisol is measured to diagnose impaired cortisol synthesis, to find out the enzyme deficiency that causes impairment along the pathway to cortisol, and to differentiate adrenal disorders.