Lacrimi de iubire episodul 100 completely free online dating sites click2protect online dating
Neurons are diverse with respect to morphology and function.
Thus, not all neurons correspond to the stereotypical motor neuron with dendrites and myelinated axons that conduct action potentials.
Several techniques such as intracellular recording, patch-clamp, and voltage-clamp technique, pharmacology, confocal imaging, molecular biology, two photon laser scanning microscopy and Ca2 imaging have been used to study activity at the cellular level.
Since memories are postulated to be represented by vastly interconnected networks of synapses in the brain, synaptic plasticity is one of the important neurochemical foundations of learning and memory (see Hebbian theory).Metabotropic receptors on the other hand activate second messenger cascade systems that result in the opening of ion channel located some place else on the same postsynaptic membrane.Although slower than ionotropic receptors that function as on-and-off switches, metabotropic receptors have the advantage of changing the cell's responsiveness to ions and other metabolites, examples being gamma amino-butyric acid (inhibitory transmitter), glutamic acid (excitatory transmitter), dopamine, norepinephrine, epinephrine, melanin, serotonin, melatonin, and substance P.An action potential can be divided into several sequential phases: threshold, rising phase, falling phase, undershoot phase, and recovery.Following several local graded depolarizations of the membrane potential, the threshold of excitation is reached, voltage-gated sodium channels are activated, which leads to an influx of Na ions.