Psyc 4, Ch 5

• ...are made in neurons
• ...found in neurons
• ...release a chemical when stimulated
• ...fit with receptor and produce a biological response
• ...have the same response when experimented with/on
• ...be inactivated after released from the receptor

Play a key role in everything we do!

1. Small-Molecule Transmitters

2. Neuropeptides

3. Transmitter Gasses

1. Release and respond to several neurotransmitters

2. Bind with different receptors

3. Give either excitatory or inhibitory signals

4. Some trasmit very rapid and brief signals; others transmit slower, longer lasting signals

Precursor molecules are absorbed in the digestive tract and delivered to neurons through blood. They are made into neurotrasmitters through an assembyline worked by enzymes.

A diet that has high/low concentrations of presursor molecules may affect what neurotrasmitters are produced.

The process of transmitting signals and their transmition is influenced by a variety of factors, including learning, maturation, stress, diet, drugs, and diseases.

Changes in these can alter the rate of production/release, number and sensitivity of receptors, firing threshold, firing rate, and/or rate of inactivation.

Dysfuctions - if processes are not normal, physical and emotional well-being, cognition, and behavior can be affected.

Made in the CNS and PNS

Roles - primary neurotrasmitter in muscle movement; key role in memory and cognitive functioning; prominent role in triggering REM sleep (dreaming)

Produced throughout the brain

Regulates/Keeps in Order: impulses, thoughts, emotions/moods, appetite, sleep, sex, pain, social behavior, aggression

Precursor molecule - tryptophan

Involved in: movement, attention, learning, perception, cognition, motivation, pleasure, and reinforcing the effects of certain drugs

Derived from DA and produced in the brain stem

Increases attention and arousal: increases alterness; accelerates thinking; stimulates fight/flight; increases mental energy, motivation, and excitment; promotes wakefulness; regulates mood; enhaces learning and memory; helps stimulate pleasure and reward; organizes the brain/body to deal with danger

Most brain activity is inhibitory

Play a key role in "braking" - suppress the activity of neurons

Two are especially important...

Most important inhibitory neurotrasmitter in the CNS; involved in almost every behavior

Roles - Reduces anxiety, promotes relaxation and sleep, reduces blood pressure and heart rate, elevates the pain threshold, promotes fine motor function, reduces seizure activity

Found mostly in the spinal cord and lower portions of the brain

Low levels of glycine cause muscles to contract and spasm

Rapidly depolarize neurons, lower the firing threshold, and increase firing rates

Principle = Glutamate - in the CNS; increases alterness, attention, arousal, and memory; excessive levels caused by oxygen deprivation can cause seizures or psychotic disorders

Groups of neurons in part of the brain start rapidly firing in sync with one another instead of is established patterns

Triggers - lack of sleep, psychological stress, hormone changes, sensory stimuli (ex. flashing lights)

Causes - head injury, brain tumors, strokes, brain infections, abnormal brain development, degenerative brain disease

Chemical compounds made of short amino acid chains that modulate the transmission of signals at the syapse, influence the firing rate, and help or inhibitt release of neurotransmitters

Can work as neuromodulators, hormones, or neurotrasmittes

Must be removed from the synapse after use but they stay active longer than neurotrasmitters

• Stimulate feelings of well-being
• Promote emotional balance
• Reduce stress
• Stimulate pleasure, reward, and euphoria
• Reduce alcohol/drug appetite
• Regulate hunger and thirst
• Enhance cognition
• Promote attachment
• Regulate sex drive

1. Neurotransmitters - released into the synaptic gap

2. Hormones - released into the blood stream

3. Neuromodulators - modulate the firing rate of other neurotransmitters

One of the primary chemicals of infatuation, lust, and romatic love

Stimulates infatuation, lust, appetite suppressant, orgasm, ovulation

"Love potion" of PEA + DA + NE is potent but does not last long

Promotes feelings of attachment and bonding behavior

Stimulates skin sensitivity and desire for touch and affectionate behavior

Associated with "true" love

High levels - monogamous; Low levels - promiscuous

Some soluable gasses function as neurotransmitters, but they function differently: exit neuron's membrane by diffusion and enter the receing neuron's membrane the same way and act upon receptors inside the neuron

Two types...

In CNS and PNS

Involved in memory formation, disgestion, penile erection, and influences the activity of other neurotrasmitters (ex. glutamate)

Seems to play an important role in modulating the production of neurotransmitters