Neurotransmitters in Psychology

Galvani Italian Physician and Physicist. He was cutting frogs’ legs as an experiment trying to prove that a frog's testicles were actually in their legs 1771 “discovered that the muscles of dead frog legs twitched when struck by a spark.” One of the first to realize the electrical patterns in all biological beings. Nature of the nervous system is electrical in part.

The Nervous System Nervous System: Consists of all the nerve cells. It is the body’s speedy, electrochemical communication system. Central Nervous System (CNS): consists of the brain and spinal cord. Processes, interprets and stores information and issues orders. Peripheral Nervous System (PNS): the sensory and motor neurons that transmit information to/from the central nervous system to the rest of the body.

Nervous System Central Nervous System (CNS) Peripheral Nervous System (PNS)

Peripheral Nervous System Somatic Nervous System: It enables voluntary control of our skeletal muscles. Ex. As you reach the bottom of a page, the SNS will report to your brain the current state of your skeletal muscles and carry instructions back, triggering your hand to turn the page. Autonomic Nervous System: Part of the PNS that controls the glands and muscles of internal organs. Operates autonomously, but can be consciously overridden. Ex. Heartbeat, digestion, glandular activity.

Autonomic Nervous System (ANS) Sympathetic Nervous System: division of the ANS that arouses the body, mobilizing its energy in stressful situations. Parasympathetic Nervous System: division of the ANS that calms the body, conserving its energy.

Autonomic Nervous System (ANS) Sympathetic NS “Arouses” (fight-or-flight) Parasympathetic NS “Calms” (rest and digest)

Central Nervous System The Brain and Neural Networks Complex Neural Network Brain receives information, interprets it, and decides responses-like a computer. Interconnected neurons form networks in the brain. These networks are complex and modify with growth and experience.

The Neuron

Neurotransmitters Neurotransmission Process Neurons send electrochemical messages from stimuli in the environment or internal body changes to the brain. The cell body of the presynaptic cell decides to send electrical impulses down its axon to the synapse (gap between cells) and eventually to the postsynaptic cell.

Neurotransmitters Neurotransmission Process Neurotransmitters (chemical substances) swim through the synapse into receptor sites on the postsynaptic cell and give it the message to either fire or not fire. Any leftover neurotransmitter is broken down or sucked back into the presynaptic cell (this is called reuptake).

Problems with Neurotransmission -Too much/too little neurotransmitter present to send the message -Not enough receptor sites on the postsynaptic cell to receive the message -Blockers that don’t allow the neurotransmitter to reach the receptor site -The reuptake process is ineffective