Final answer:
The neuron doctrine was postulated by Santiago Ramón y Cajal, while the law of dynamic polarization was postulated by Wilhem His.
Step-by-step explanation:
Neuron Doctrine and Law of Dynamic Polarization
The neuron doctrine states that the nervous system is composed of individual cells called neurons. It was postulated by Santiago Ramón y Cajal, a Spanish neuroscientist, in the late 19th century. He used Golgi staining to study the structure of neurons and proposed that they are discrete units that communicate through synapses.
The law of dynamic polarization, also known as the dendritic directionality principle, was postulated by Wilhem His, a Swiss anatomist, in the late 19th century. According to this law, information flows in one direction within a neuron, from the dendrites to the cell body and then to the axon terminal.