Good Morning

2-1 57-65

Neural Communication: Biological Psychology, Anatomy of Neurons (location and function of all parts), Neural Firing- Action Potential Process, Synapse, Reuptake Process, Neurotransmitters - Roles of Acetylcholine, Dopamine, Serotonin, Norepinephrine, GABA, Glutamate, Endorphins; Agonists, Antagonists, Curare, Botulin, Blood-Brain Barrier

1. Identify the parts of a neuron and give their functions.

2. Describe the Action Potential Process.

3. Discuss the role of the major neurotransmitters.

4. Differentiate agonists and antagonists and give examples of each.

NEUROSCIENCE – YAY!!

Chapter 2 Neuroscience,

Geneticsand Behavior

Neural Communication

Biological Psychology branch of psychology concerned with the links

between biology and behavior some biological psychologists call themselves

behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists

Neuron a nerve cell the basic building block of the nervous system

Neural Communication Dendrite

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body

Axon the extension of a neuron that carries messages away

from the cell body some are quite long 2 to 3 feet in length Myelin [MY-uh-lin] Sheath white fatty layer that insulates some axons helps speed up neural impulses Multiple Sclerosis is a disease in which the myelin

sheath degenerates-leads to loss of muscle control

Neural CommunicationCell Body=Soma

Terminal Button

Neural Communication

Action Potential action potential- a neural impulse; is a brief

electrical charge neurons generate electricity from

chemical events resting neurons are full of negative ions,

while fluid outside is positively charged –known as resting potential

-when a neuron fires, the axon opens its gates and lets in positive Potassium ions—sets of a chain reaction

Neural Communication

ACTION POTENTIAL cont’dexcitatory vs. inhibitory messages dendrite of a neuron receives both types of

signals -If # of excitatory – # of inhibitory signals is above

the threshold the neuron fires -the level of stimulation required to trigger a

neural impulse RESTING POTENTIAL =-70 MICROVOLTS -all-or-none response; it fires or it doesn’t Refractory Period – the time b/w neural firings

w/in which a neuron cannot fire (toilet flush metaphor), Resting Pause

“Volley Principle”

Neural Communication

Cell body end of axon

Direction of neural impulse: toward axon terminals

Neural Communication

Synapse [SIN-aps] junction between the axon tip of the

sending neuron and the dendrite or cell body of the receiving neuron

tiny gap at this junction is called the synaptic gap or cleft

Sir Charles Sherrington

Neural Communication(Postsynaptic Neuron)

(Presynaptic Neuron)

/gap

Neural Communication -axon terminals-branching terminals that send

messages to the next neuron -contain sacs that hold

neurotransmitters NEUROTRANSMITTERS cross the synaptic gap and

bind to receptor sites on the dendrite of the next neuron

lock and key relationship this opens up the gates for the ions to pass through

either excites or inhibits the action potential influencing whether it will generate a neural impulse

Neural Communication reuptake- process where excess

neurotransmitters are reabsorbed by the sending neuron

-agonists excite neurons by mimicking natural neurotransmitters or blocking their reuptake to keep more of them in your system

-antagonists inhibit neural impulses by blocking receptor sites or diminishing their release

Neural Communication

Serotonin Pathways Dopamine Pathways

Neural Communication

Neural Communication

Acetylcholine ACh involved in muscle contraction, learning and

memory people with Alzheimer’s lose the ability to

produce acetylcholine -if its transmission is blocked our

muscles can’t contract and we become paralyzed

-Poison darts -too much may lead to violent muscle

contractions and seizures (black widow spider)

Neural Communication

Endorphins- natural opiates released in response to pain and vigorous exercise

-“endogenous morphine” Pert & Snyder blood-brain barrier- which is a membrane

that only lets certain chemicals pass through Parkinson’s -lack dopamine, but dopamine can’t

cross the barrier—therefore we can’t give them dopamine

-L-Dopa must be used (kinda like synthetic dopamine) because it can cross the barrier

Neural Communication

Neurotransmitter molecule

Receiving cellmembrane

Receptor site onreceiving neuron

Agonist mimicsneurotransmitter

Antagonistblocksneurotransmitter

Good Morning

2-2 61-67 NERVOUS & ENDOCRINE SYSTEM1. Describe the nervous system’s two major divisions and identify the three

types of neurons that transmit information through the system.

2. Identify the subdivisions of the peripheral nervous system, and describe their functions.

3. Describe the simplicity of the reflex pathways.

4. Describe the nature and functions of the endocrine system and its interaction with the nervous system.

The Nervous System Nervous System

the body’s speedy, electrochemical communication system

consists of all the nerve cells of the peripheral and central nervous systems

Central Nervous System (CNS) the brain and spinal cord

Peripheral Nervous System (PNS) the sensory and motor neurons that connect the

central nervous system (CNS) to the rest of the body

The Nervous System

Central(brain and

spinal cord)

Nervoussystem

Autonomic (controlsself-regulated action of

internal organs and glands)

Skeletal (controlsvoluntary movements of

skeletal muscles)

Sympathetic (arousing)

Parasympathetic (calming)

Peripheral

The Nervous System

Nerves neural “cables” containing many axons part of the peripheral nervous system connect the central nervous system with muscles,

glands, and sense organs Sensory Neurons (Afferent)

neurons that carry incoming information from the sense receptors to the central nervous system

The Nervous System Interneurons

CNS neurons that internally communicate and intervene between the sensory inputs and motor outputs

Motor Neurons (Efferent) carry outgoing information from the CNS to muscles

and glands SAME:Sensory=Afferent, Motor=Efferent

Somatic Nervous System the division of the peripheral nervous system that

controls the body’s skeletal muscles

The Nervous System Autonomic Nervous System

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart)

Sympathetic Nervous System division of the autonomic nervous system that

arouses the body, mobilizing its energy in stressful situations

Parasympathetic Nervous System division of the autonomic nervous system that

calms the body, conserving its energy

The Nervous System

The Nervous System

The Nervous System Reflex

a simple, automatic, inborn response to a sensory stimulus

Skinreceptors

Muscle

Sensory neuron(incoming information)

Motor neuron(outgoing information)

Brain

Interneuron

Spinal cord

The Nervous System Neural Networks

interconnected neural cells

with experience, networks can learn, as feedback strengthens or inhibits connections that produce certain results

computer simulations of neural networks show analogous learning

Inputs Outputs

Neurons in the brain connect with one

another to form networks

The brain learns by modifyingcertain connections in response to feedback

The Brain

Lesion tissue destruction a brain lesion is a

naturally or experimentally caused destruction of brain tissue

The Endocrine System

Endocrine System the body’s “slow”

chemical communication system (v. Neurotransmitters –faster but shorter lasting)

a set of glands that secrete hormones into the bloodstream

Neural and Hormonal Systems        The Endocrine System -set of glands that secrete hormones into the blood stream -hormones – chemical messengers that are produced in one

tissue and affect another  -some hormones are very similar in structure to

neurotransmitters -most are much slower acting than neurotransmitters -n-mitters travel along neural pathways, hormones travel in the

blood  pituitary gland –master gland, produces or controls release of

many diff. Types of hormones -located under hypothalamus which controls it -adrenal glands- pair of endocrine glands located just above the

kidneys -release epinephrine and Norepinephrine (aka adrenaline

and noradrenaline) -provide us with energy surges when under stress or pressure

(work with sympathetic nervous system)

Electroencephalogram (EEG)

an amplified recording of the waves of electrical activity that sweep across the brain’s surface

these waves are measured by electrodes placed on the scalp

The Brain CT (computed tomography) Scan

a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body; also called CAT scan

PET (positron emission tomography) Scan a visual display of brain activity that detects where a

radioactive form of glucose goes while the brain performs a given task

MRI (magnetic resonance imaging) a technique that uses magnetic fields and radio waves to

produce computer-generated images that distinguish among different types of soft tissue; allows us to see structures within the brain

PET Scan

MRI Scan

The Brain

Brainstem the oldest part and central core of the

brain, beginning where the spinal cord swells as it enters the skull

responsible for automatic survival functions Medulla [muh-DUL-uh]

base of the brainstem controls heartbeat and breathing

The Brain

The Brain

Reticular Formation a nerve network in the brainstem that plays

an important role in controlling arousal Thalamus [THAL-uh-muss]

the brain’s sensory switchboard, located on top of the brainstem

it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

The Brain

Cerebellum [sehr-uh-BELL-um] the “little brain”

attached to the rear of the brainstem

it helps coordinate voluntary movement and balance

The Brain Limbic System

a doughnut-shaped system of neural structures at the border of the brainstem and cerebral hemispheres

associated with emotions such as fear and aggression and drives such as those for food and sex

includes the hippocampus, amygdala, and hypothalamus.

Amygdala [ah-MIG-dah-la] two almond-shaped neural clusters that are

components of the limbic system and are linked to emotion

The Brain Hypothalamus

neural structure lying below (hypo) the thalamus; directs several maintenance activities eating drinking body temperature

helps govern the endocrine system via the pituitary gland

is linked to emotion

The Limbic System

The Limbic System

Electrode implanted in reward center

The Cerebral Cortex

Cerebral Cortex the intricate fabric of

interconnected neural cells that covers the cerebral hemispheres

the body’s ultimate control and information processing center

Glial Cells cells in the nervous system that

support, nourish, and protect neurons

The Cerebral Cortex

Frontal Lobes involved in speaking and muscle movements

and in making plans and judgments Parietal Lobes

include the sensory cortex Occipital Lobes

include the visual areas, which receive visual information from the opposite visual field

Temporal Lobes include the auditory areas

The Cerebral Cortex

The Cerebral Cortex

Motor Cortex area at the rear of the frontal lobes that

controls voluntary movements Sensory Cortex

area at the front of the parietal lobes that registers and processes body sensations

The Cerebral Cortex

The Cerebral Cortex

Functional MRI scan shows the visual cortex activated as the subject looks at faces

Visual and Auditory Cortex

The Cerebral Cortex

1. Describe the findings of split-brain research and its expansion of knowledge on hemispheric specialization.

Association Areas More intellegent animals have increased

“uncommitted” or association areas of the cortex

The Cerebral Cortex

Aphasia impairment of language, usually caused by left

hemisphere damage either to Broca’s area (impairing speaking) or to Wernicke’s area (impairing understanding)

Broca’s Area an area of the left frontal lobe that directs the

muscle movements involved in speech (damage also effects signing capability)

Wernicke’s Area an area of the left temporal lobe involved in

language comprehension and expression

Specialization and Integration

Specialization and Integration

Brain activity when hearing, seeing, and speaking words

Brain Reorganization

Plasticity the brain’s capacity for modification, as

evident in brain reorganization following damage (especially in children) and in experiments on the effects of experience on brain development

“Blind-Girl Study” “Phantom Sensations”Hemispherectomy Patient- 5 yr old later scored

above average on intel tests, completed college & grad school

Our Divided Brain

Left – Language/Verbal, Logical, Sequences Left is interpretive; Brain’s press agent; constructs

theories to explain our behavior

Right – Emotionally Intuitive, Expressive, Spatial Relations, Multi-Tasks (can do many things at once unlike the sequential left-brain)

Drawing: p 86 “Which one is happier?”

VIDEO MODULE: THE BRAIN: “The Divided Brain”

Our Divided Brain -accidents, strokes,

and tumors in the left hemisphere generally impair reading, writing, speaking, arithmetic reasoning and understanding

-similar damage in the right hemisphere rarely have such dramatic effects

-corpus-callosum –200 mil neural fibers connecting hemispheres

1960s surgery - severing

Corpus callosum

Our Divided Brain

The information highway from the eye to the brain

Split-Brain Patient

Split Brain

a condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers (mainly those of the corpus callosum) between them

Split Brain

“Look at the dot.” Two words separatedby a dot are momentarily projected.

“What worddid you see?”

or

“Point withyour left hand to theword you saw.”

Disappearing Southpaws

Left Hand vs. Right Hand 90% of humans are right handed 10% left-handed 95% of righties have lang based in left hem 50% of lefties have lang based in left hem 25% in the right 25% mixture -lefties more likely to have reading disabilities, allergies, and migraines -also more commonly musicians , math wiz’s, artists ,and MLB players -for some reason (no one knows) the older the population you study, the less % of left handers there is

Disappearing Southpaws

The percentage of left-handers decreases sharply in samples of older people (adapted from Coren, 1993).

The percentage of lefties sharplydeclines with age

10 20 30 40 50 60 70 80 90Age in years

14%

12

10

8

6

4

2

0

Percentage ofleft-handedness

Brain Structures and their Functions

The Endocrine System

Endocrine System the body’s “slow”

chemical communication system (v. Neurotransmitters –faster but shorter lasting)

a set of glands that secrete hormones into the bloodstream

Neural and Hormonal Systems        The Endocrine System -set of glands that secrete hormones into the blood stream -hormones – chemical messengers that are produced in one

tissue and affect another  -some hormones are very similar in structure to

neurotransmitters -most are much slower acting than neurotransmitters -n-mitters travel along neural pathways, hormones travel in the

blood  pituitary gland –master gland, produces or controls release of

many diff. Types of hormones -located under hypothalamus which controls it -adrenal glands- pair of endocrine glands located just above the

kidneys -release epinephrine and Norepinephrine (aka adrenaline

and noradrenaline) -provide us with energy surges when under stress or pressure

(work with sympathetic nervous system)