New drug that significantly improved performance on a learning task in Essay

New drug that significantly improved performance on a learning task in human - Essay Example This electrical impulse is one unit of neural information. An electrical impulse flowing along the length of a neuron is called nerve impulse. Nerve impulses are unidirectional within a neuron – from the dendrite through the cell body and axon, to the axon terminals. In addition, neurons produce nerve impulses in an all-or-nothing way. For example, if the stimulus that a neuron receives is too weak to trigger a nerve impulse, nothing happens – the neuron does not initiate an impulse. However, if the stimulus is strong enough, the neuron does initiate an impulse. What happens when an impulse reaches the end of one neuron and move to another neuron? The junction between two neurons or between a neuron and a muscle is called a synapse. The two cells involved in a synapse do not physically touch each other instead they are separated by a small space. The cell that carries the impulse to the synapse is the synaptic cell and the cell that receives the impulse is the postsynaptic cell. When an impulse that is travelling along the postsynaptic cell reaches the end of the axon, it causes the cell to release molecules known as neurotransmitters. These molecules are released into the synapse and diffuse approximately 20 millionths of a millimetre to where they bind with receptors on the dendrites of the postsynaptic cell. When neurotransmitters bind to the receptors, the charge across the postsynaptic membrane changes and if the change is great enough, it triggers a nerve impulse, the nerve impulse then travels along the postsynaptic cell. Dopamine (DA) is a predominant catecholamine neurotransmitter in the mammalian brain where it controls a variety of functions including locomotor activity, cognition, emotion, positive reinforcement, etc. The chemical is naturally produced in the body (brain region). Dopamine, the neurotransmitter activates dopamine receptors. In addition,