Impact of neurotransmitters on physical and mental behavior

Psychology

Impact of Neurotransmitters on Physical and Mental Behavior

Neurotransmitters are free floating chemicals that are located in the brain. They transmit signals in the synapse controlling a lot of a person's physical and mental behavior. There are four major neurotransmitters: 1) Dopamine, 2) Acetylcholine, 3) Norepinephrine and 4) Serotonin. These chemicals allow the transmission of signals from one neuron to the next across synapses. They are also found at the axon endings of motor neurons, where they motivate the muscle fibers. And they and their close relatives are formed by some glands such as the pituitary and the adrenal glands (Carlson, 2011).

Dopamine

Dopamine is a vital neurotransmitter that controls several key functions in the brain, such as motor output, motivation and reward, learning and memory, and endocrine regulation. Dopamine does not mediate fast synaptic transmission, but rather adjusts it by triggering slow-acting effects by way of the activation of dopamine receptors (Rondo, Hageman & Van Craenenbroeck, 2010). The dopamine system is important in: behavioral switching, incorporation of emotive to motor behaviors, the four F's of appetitive behaviors like feeding, fighting, fleeing and sexual behaviors, hedonic or pleasurable properties of natural and drug-related reinforcement and extra pyramidal (extra-motor) control (Biogenic Amine Neurotransmitters in the CNS, n.d.).

Acetylcholine

Acetylcholine is the neurotransmitter formed by neurons referred to as cholinergic neurons. In the peripheral nervous system acetylcholine plays a role in skeletal muscle movement, as well as in the regulation of smooth muscle and cardiac muscle. In the central nervous system acetylcholine is thought to be involved in learning, memory, and mood.

Acetylcholine is synthesized from choline and acetyl coenzyme A by way of the action of the enzyme choline acetyltransferase and becomes packaged into membrane-bound vesicles. After the appearance of a nerve signal at the termination of an axon, the vesicles combine with the cell membrane, causing the discharge of acetylcholine into the synaptic cleft. For the nerve signal to carry on, acetylcholine must disperse to another nearby neuron or muscle cell, where it will bind and make active a receptor protein (Acetylcholine, 2011).

The acetylcholine system is significant in: mediating input to Renshaw cells in the spinal cord, as interneuron's in the basal ganglia and nucleus accumbens, contributing to arousal and learning and to motor control (Biogenic Amine Neurotransmitters in the CNS, n.d.).

Norepinephrine

Norepinephrine, one of the monoamine neurotransmitters in the central nervous system, has been reported to be connected to several functions such as memory, cognition, consciousness, and emotion. It plays significant roles in the path physiology of depression. Norepinephrine transporter (NET) is responsible for the reuptake of norepinephrine into presynaptic nerves and is one of the main targets of antidepressants (Sekine, Arakawa, Ito, Okumura, Sasaki, Takahashi & Suhara, 2010). The norepinephrine system is important in: attention like alerting, focusing and orienting, appetitive behaviors, hedonic or pleasurable properties of natural and drug-related reinforcement and mood, arousal, and regulation of blood pressure (Biogenic Amine Neurotransmitters in the CNS, n.d.).