The Brain and Behavior

McElhaney

Biopsychology= Bio explanation/cause for behavior. Or Physiological Psychology

Includes Electro/Chemical processes Brain Anatomy The Study of Biological Aspects of

Behavior Hormonal aspects of behavior Hemisphere specialization

Phineas Gage- Frontal Lobe injury Suffered brain injury that caused changes in his

personality and behavior.

Brain Mapping

We know about the brain through experiments

Where portions of the brain are stopped, in order to identify locals of control.

What tools do Doctors have in determining Brain Function?

EEG CAT Scan MRI PET Scan Role of Glucose

Tools for Viewing Brain Structure and Activity

EEG Electroencephalogram measures electrical

currents across the brain

Measure brain activity And Location of different

functions

Tools for Viewing Brain Structure and Activity

CT scan Also called a CAT scan Computerized axial

tomography X-ray of brain tissue Shows brain structure Cross section images

Snapshots of the Brain

PET scan Positron Emissions

Tomography Patients drinks

radioactive glucose* and image shows areas of brain activity or as it’s working.

*Glucose is the primary fuel of the Brain as it is working. More glucose in an area means brain is working.

Tools for Viewing Brain Structure and Activity

MRI Magnetic Resonance

Imaging Exposes brain to

magnetic field Shows brain structure

Neurons are the basic building blocks

AKA Nerve Cells – 100 Billion in brain

Carries and processes information

Connected via Chains of specailzed information

Activate Muscles & Glands Non are identical

The Neuron and what it does

Dendrites= “Tree Roots” receives and messages from other neurons

Soma – cell body, sends Nerve Impulses

Axon- Fibrous carrier of impulses Axon Terminals- end of Axon Myelin Sheath- insulating body

surrounding the axon

Nerve Impulse- “Firing” of a nerve

Ions= sodium (Na) Electrical Charged molecules are in each neuron

Electrical charge of <-70> Millivolts Threshold = trigger point for sending a

message Nerve Impulse- will be fired when <-50>

Millivolts are reached =Action Potential Gates open and allow flow of ions- sodium

goes in Potassium out

Action Potential

Psych Jeopardy Review

Choose group of 5 people Divide Key Terms form reading (part

2 recommended) Make questions/answers on

flashcards (at least 10) Play Jeopardy monday

Quiz Thursday:

Neuron and its components Nerve Impulse and Action Potential Synapse Neurotransmitters

Synapses and Neurotransmitters Info is transmitted chemically Synapse = space between neurons Between Axon terminals and Dendrites Neurotransmitter=a chemical released by a

neuron that stimulates nearby neurons and allows for nerve impulses to be passed throughout the body

Neurotransmitters are kept in vesicles, which fuse with the axon terminal’s membrane and travel into the synaptic cleft, ready to bind to receptors in the postsynaptic membrane

What a neurotransmitter looks like…

Receptors are found at each end of the neuron- cell body and dendrite

Neurotransmitters can slow or speed up firing of neuron

There are over 100 transmitter chemicals

Facts and Such.

Everything you do or feel occurs due to communication between different neurons, which provide information throughout the nervous system. Within a single neuron, information travels through electrical signals, but when information is transmitted from one neuron to the next neuron, the transmission is considered ‘chemical’.

For two neurons to communicate neurotransmitters (messengers) are released into the synaptic cleft (an extremely tiny gap between neurons), where they then move to the next neuron and attach themselves to locations called receptor sites.

The result is an initiation of electrical current that moves through that neuron toward the next one. After the neurotransmitter does its thing, it is either destroyed by other chemicals in the synaptic cleft or is taken back into its original neuron. This action prevents the neurons from becoming ‘overstimulated’.

When neurons communicate, the effect can either help or hinder the next neuron. For example, when a person pays attention to one conversation and ignores others, the neurons in the brain are ‘listening’ to that information (helping) and ignoring the rest (hindering). Neurons come in different shapes and sizes, affecting many other neurons, and can have different numbers of synapses. Some neurons, called Purkinje cells, may have as many as 100,000 synapses.

Neurotransmitters

Chemicals that influence the firing of nerve cellsCan “excite”-make firing more likelyOr “inhibit” make firing less likely

Neurotransmitter Function Associated Diseases

Acetylcholine Found at neuromuscular junction; memory and learning

Alzheimer’s disease (decreased Ach)Black widow spider (increased Ach)Botox (decreased Ach)Curare (decreased Ach)

Dopamine Movement, muscle control, learning, attention, emotions, and rewards

Parkinson’s disease (decreased dopamine)Schizophrenia (increased dopamine)Depression (decreased dopamine)

Serotonin Sleep, mood, hunger, arousal Depression (decreased serotonin)

Anorexia (increased serotonin)

Sleep disordersNorepinephrine Fight or flight response Depression (decreased NE)

Endorphins (endogenous opiates)

Pain, emotions Mimicked by opiates (heroin, morphine, codeine)Runners highNeurostimulation

GABA (gamma amino-butyric acid)

Hunger and sleep, inhibits CNS

Alcohol consumption causes an increase in GABA

Effects of Drugs + Meds on Neurotransmitters

Alcohol- Increases GABA, Increases Dopamine

Prozac- Increases Serotonin levels Same with Zoloft, Paxil, Celexa, Luvox

Opiates- Increases Dopamine, Mimics Endorphins Morphine and heroin

Nicotine- Imitates Acetylcholine

Drugs and Neurotransmitters

Psychoactive medications: Imitate Duplicate Or blocks Neurotransmitters

Curare = poison

Prevents Acetylcholine- up take And causes paralysis

Endorphins

Endorphins are a group of small proteins naturally occurring in the brain around nerve endings that bind to opiate receptors

Natural opiates produced in the brain which function as the body’s own natural painkillers and Elevate mood.

Endorphins respond to morphine Enkephalins= opiate like neural regulators

relieve pain & stress similar to endorphins

Organization of the Nervous System

Central Nervous System

Peripheral Nervous System

Controls the voluntary behavior Carries information to and from the

Central Nervous System Peripheral nervous system is made up of: Somatic System Autonomic System Sympathetic Branch Parasympathetic Branch

Peripheral Nervous System

Somatic System- controls voluntary behavior

Sense organs and skeletal muscles

Autonomic Nervous System

Sympathetic and Parasympathetic

Both systems work together:

Emotional responses and Involuntary behavior

Sympathetic:“Emergency System”Fight or FlightArouses body for action

Parasympathetic= quiets body,

returns to lower level of arousal, after emotional event

Vital functions, heart rate, breathing, digestion

Types of Neurons

Sensory Neurons – Afferent Neurons

Carry the message from the sense organs to the CNS

Inter neurons Make up the CNS

Motor Neurons – Efferent Neurons

Carry the message from the CNS to the muscles or glands

Remember – SAME (sensory = afferent, motor = efferent)

Brain Stem

Medulla– where spinal cord meets the skull; controls heartbeat and breathing

Reticular formation– bundle of nerves running through the brainstem; controls arousal and attention; filters incoming stimuli and relays important information to the brain.

Cerebral Cortex

Controls information processing; wrinkled to increase surface area

Composed of 8 lobes (4 on each side)

Corpus Callosum

bundle of nerves connecting the left and right hemispheres

Parietal Lobes

Located on the top and rear of head

Contains the sensory cortex (part of brain that registers and processes tactile information (phantom limb)

Contains the angular gyrus (left hemisphere only) which is involved in converting written words into sound

Frontal Lobes

Located in the forehead region

Includes the motor cortex (part of brain that controls voluntary movement)

Includes Broca’s area (needed for forming words; located in left hemisphere only)

Association areas in this region – judgment, planning, processing new memories

Occipital Lobes

Located in the back of the head

Contains the visual cortex

Temporal Lobes

Located on the sides of head, above ears

Receives and processes auditory information

Includes Wernicke’s area (left hemisphere only) - part of brain involved in understanding language

Cerebellum

Controls balance and coordination

In the rear of the head, behind the brainstem

Thalamus

Pair of egg-shaped organs above the brainstem; receives information from the senses (EXCEPT FOR SMELL) and relays it to the rest of the brain.

Thalamus

Limbic System

Amygdala – two almond shaped structures; influence fear and aggression (monkeys and cats)

Hypothalamus – below the thalamus; regulates hunger, thirst, body temp, sex, fight-or-flight; triggers the pituitary (the “master gland”); reward center

Hippocampus – behind the amygdala; memory

The Brain

Gray matter – areas of the CNS with high concentrations of cell bodies; outer surface of cerebrum (cerebral cortex)

White matter – areas of the CNS with mostly myelinated axons; inner part of cerebrum

Glial cells – cells in the brain that nourish and protect neurons

Name that brain part