Neuroscience and Behavior

T/F: We only use 10% of our brains: Lucy

It’s all about the body!crash course

Neural Communication

Neuron – a nerve cell; “building block” of the nervous system Icons of Science

Neuroanatomy(include glial cells)

Khan Academy, stop @ 3:30

Neuroanatomy

• Synapse – the junction (space) between the axon of one neuron and the dendrite of another

• Neurotransmitter – chemicals that carry messages across the synapse from one neuron to another

How a Neuron FiresKhan: stop @ 4:45

• an electrochemical process– Electrical inside the neuron;

chemical outside the neuron (neurotransmitters).

• called an action potential• an “all or nothing” process– like a gun– greater intensity of stimulus does

not equal faster/more intense firing; greater stimulus can mean more neurons firing or more frequent firing

Action Potential1. Resting Potential - the neuron is ready

to fire 2. Reaches its threshold , then fires based

on the all-or-none response3. Polarization Depolarization

a) opens up portals in axon letting in positive ions (Sodium) which mix with negative ions (Potassium) that are already inside the axon

b) process continues down axon to the axon terminal

4. Terminal buttons convert electrical charge into chemical response (neurotransmitter) and sends message to next neuron, across the synapse

Action Potential

The Role of Neurotransmitters

•Excitatory - neurotransmitter effect that makes it more likely that the receiving neuron will generate an action potential or “fire”• Inhibitory - neurotransmitter effect that makes it less likely that the receiving neuron will generate an action potential or “fire”

SPECIFIC NEUROTRANSMITTERS

Acetylcholine (ACh)• vital role in

movement and memory

• too much – muscle contractions, convulsions– some spider venoms

cause floods of ACh• too little – immobility,

extreme lethargy– Botulin causes

paralysis by blocking its release

• Undersupply of ACh has been linked to Alzheimer’s disease

Dopamine

• deals with movement, learning, attention & emotion

• lack of dopamine has been linked to Parkinson’s Disease

• too much has been linked to Schizophrenia

Serotonin

• involved in mood control, hunger, sleep / arousal

• lack of serotonin has been linked to clinical depression (Prozac and other antidepressants raise serotonin levels)

Endorphins• “endogenous

morphine”• involved in pain

control• most addictive

drugs work with endorphins

Neurotransmission Drugs• Agonists - mimics / blocks reuptake /

excites• Antagonists - prevents release / blocks /

inhibits

Types of NeuronsKhan;start @ 4:50

• Efferent (Motor) Neurons– info to body parts for

movement

• Interneurons– info within central nervous

system

• Afferent (Sensory) Neurons– info to CNS from body parts

• Remember… S.A.M.E.

A Neural Chain

A Neural Chain

A Neural Chain

A Neural Chain

The Nervous Systemcrash course

Khan

Central Nervous System

• brain and spinal cord• CNS

Peripheral Nervous System

• all nerves that are not encased in bone

• everything but the brain and spinal cord

• divided into two categories– somatic– autonomic

Somatic Nervous System

• controls voluntary muscle movement

• uses motor (efferent) neurons

Autonomic Nervous System

• controls the automatic functions of the body

• divided into two categories– sympathetic– parasympathetic

Sympathetic Nervous System

• “Fight or Flight” response

• automatically accelerates heart rate, breathing, dilates pupils, slows down digestion

Parasympathetic Nervous System

• automatically calms the body down after a stressful event

• heart rate and breathing slow down, pupils constrict, and digestion speeds up

• think, “parachute”

Reflexes

• normally, afferent neurons spine brain & brain sends orders for movement efferent neurons

• some reactions occur when sensory neurons reach just the spinal cord & spinal cord sends orders

Neural NetworksHow much of our brain do we actually use?

• interconnected neurons• regular connections or

routes of communication for different tasks, processes, etc.

• body/brain “learns” networks over time

• “muscle memory” in sports (“practice makes permanent”)

brain rap

Ways to Study the Brain

• Case Studies / Clinical Observation– Accidents (i.e. –

Phineas Gage)– Diseases /

Disorders

Invasive Exploration

• Lesion - a natural or man-made destruction of brain tissue• Electrical

Probing• Psychosurgery

Less Invasive Methods

• Electroencephalogram (EEG)

• Computerized Axial Tomography (CAT Scan / CT Scan)

• Magnetic Resonance Imaging (MRI)

• Positron Emission Tomography (PET)

• Functional MRI (fMRI)

The BrainPinky & the Brain

• made up of…– neurons – glial cells (or glia -

support neural cells by insulating them, removing waste, etc.)

– connective tissues– cerebrospinal fluid

• can be divided into three major sections: hindbrain, midbrain, forebrain

Brain Structuresbrain mneumonics

• Be familiar with functions/roles.

• Location / ability to label might be helpful, but not required.

Our Super Brain!

For your assigned brain area:-Where is it located?-What is it’s main functions?-Create a superhero or supervillain with extra strength in this part of his or her brain that gives them their super powers (be sure to include what his /her power is). .

Brainstem• Pons - involved in sleep,

arousal, facial recognition• Medulla Oblongata

located just above the spinal cord

involved in the control of heart rate, blood pressure, respiration.

• Reticular Formation - arousal and ability to focus attention

Cerebellum

• coordinates voluntary muscle movements

• balance/coordination• injury = difficulty

walking, keeping balance, shaking hands, etc.

Thalamusswitchboard example

• Receives sensory information and sends them to appropriate areas of forebrain.

• Like a switchboard.

• Everything but smell.

Limbic System#24

• EMOTIONAL CONTROL CENTER of the brain.

• Made up of Hypothalamus, Amygdala and Hippocampus.

Hypothalamus• Pea sized in brain,

but plays a not so pea sized role.

• Body temperature• Hunger• Thirst• Sexual Arousal

(libido)• Endocrine System

Hippocampus and Amygdala

• Hippocampus is involved in forming new memories.

• Amygdala is vital for our basic emotions.

Cerebral Cortex

• Top layer of our brain.

• Contains wrinkles called fissures.

• The fissures increase surface area of our brain.

• Laid out it would be about the size of a large pizza.

Hemispheres

• Divided into a left and right hemisphere.

• Contralateral controlled- left controls right side of body and vice versa.

• Brain Lateralization.

Split-Brain Patients

• Corpus Collosum attaches the two hemispheres of cerebral cortex.

• right & left sides working together?

• When removed (usually b/c of severe seizures) you have a split-brain patient. #5

Areas of the Cerebral Cortex

• Divided into eight lobes, four in each hemisphere (frontal, parietal, occipital and temporal).

• Any area not dealing with our senses or muscle movements are called association areas.

Frontal Lobe

• Deals with planning, maintaining emotional control and abstract thought.

• Contains Broca’s Area.

• Broca’s Aphasia.• Contains Motor

Cortex.

Parietal Lobes

• Located at the top of our head.

• Contains the somato-sensory cortex.

• Rest are association areas (intelligence!).

Occipital Lobes

• In the back of our head.

• Handles visual input from eyes.

• Right half of each retina goes to left occipital lobe and vice versa.

Temporal Lobes

• Process sound sensed by ears.

• Not lateralized.• Contains

Wernicke’s area.• Wernicke’s

Aphasia.

Build a Brain!

Using the materials provided build a brain and label the following areas:-Frontal Lobe -Temporal Lobe-Parietal Lobe -Occipital Lobe-Cerebellum -Brain Stem

Also include one specific function of that area in your label.Then on a separate piece of paper, write down how each part of your brain is engaged in this activity.

Brain Plasticity# 7

• ability of our brains to form new connections (repair itself) after being damaged

• the younger you are, the more “plastic” your brain is

The Endocrine Systema system of glands that secrete

hormones into the bloodstreamsimilar to nervous system,

except hormones work a lot slower than neurotransmitters

Neurotransmitters

Hormones

Endocrine System

• System of glands that secrete hormones.

• Controlled by the hypothalamus.

• Ovaries and Testes.• Adrenal Gland• Epinephrine-energy

boost (adrenaline)

Common Hormones That Influence Behavior

Hormone Where? What does it do? Too much?

Not enough?

Epinephrine(Adrenaline)

Adrenal gland

-stress management-fight or flight

Melatonin Pineal gland

-regulated circadian rhythm (sleep/wake cycle)

Oxytocin Pituitary gland

-romantic attraction -bonding (romantic, parental)-regulates fear and anxiety-increased empathy

Testosterone Testes (m)Ovaries (f)

-aggression-libido-encourages risk taking

Estrogen Ovaries (f)Testes (m)

-regulates mood (f)-regulates compulsive behavior (m)-libido (f)

Nervous System v. Endocrine System

Nervous System Endocrine System

Signal

Transmission

Speed

Duration

Compare and Contrast the Nervous and Endocrine Systems using the following chart:

Nervous System Endocrine System

Signal Nerve impulses Hormones

Transmission Along neural networks

Carried in the blood stream

Speed Super fast- nearly instantaneous

Much slower

Duration Fraction of a second

Much longer lasting

• hold your stomach!

• So what’s the REAL significance of this chapter??