Electrochemistry and Biochemistry of Nerve Impulse Generation and Its Propagation

Nerve impulse transmission occurs based on three successive electrochemical processes: at rest, the concentration gradient of ions across the axon membrane produces the resting potential (−60 mV) called K⁺potential, leading to polarization; nerve impulse produces the action potential called Na⁺potential (+30 mV), causing depolarization (i.e., on excitation, there is a swing from a K⁺ potential of −60 mV to an Na⁺ potential of +30 mV) and the electrical current produced due to the action potential propagates forward; lastly, the resting potential is recovered by repolarization via an Na⁺ pump mechanism. The selectivity of Na⁺ and K⁺ ion channels has been rationalized in terms of their dehydration energies and size-matching factors. Synaptic transmission carrying the signal from one neuron to another neuron is mediated by the neurotransmitter through a chemical mechanism. Many drugs are known to affect the nervous system by interfering with the synaptic transmission mechanism. In this study, the biochemistry behind cocaine addiction and Parkinson’s disease has been discussed.