The Biology of Behavior

Biology of Behavior (8-10% of the AP Exam)

Before we start. . .

A website to help you review.

It’s COOL!

http://www.g2conline.org/

The Neuron

Basic info Structure

Click icon to add picture

Trans parency

The Electrochemical Process

The neuron is adapted for sending and receiving

signals.This is done within and

between neurons.HOW?

Within the cell, the nature of the neural impulse is electrical.

All-or-nothing Principle

Impulse along the axon is called axonal transmission

The nature of the neural impulse is electrical.

The neuron at rest is more negative inside the cell membrane relative to outside the membrane. The resting neural potential is about -70 mV.

The resting potential results from the selective permeability of the membrane, the presence of electrically charged particles called ions near the inside and outside surfaces of the membrane and resulting concentration and electrical gradients. The sodium potassium pump and blocking of ionic channels by calcium ions help maintain the resting potential.

The nature of the neural impulse is electrical

When sufficiently stimulated (to threshold) a net flow of sodium ions into the cell occurs (along with the movement of potassium ions out).

The potential rapidly reverses its polarity to typically +40mV very briefly.

The brief change in potential is call the action potential. This neural impulse travels down the length of the axon to the axon terminals.

The nature of the neural impulse is electrical

The more intense a stimulus, the more frequent a neuron fires.

A brief period of time, called the refractory period, follows the polarization changes during which the neuron is resistant to a retriggering of an action potential.

The chemical process is via neurotransmitters

Dozens of chemicals have been identified that

perform different functions in the brain.

Basic Neurotransmitters

Acetylcholine (ACh)

Controls skeletal muscles

Contributes to the regulation of attention, arousal and memory

Some ACh receptors are stimulated by nicotine

Dopamine (DA)

Contributes to control of voluntary movement, pleasurable emotions

Decreased levels associated with Parkinson’s Disease

Overactive at DA synapses associated with schizophrenia

Cocaine and amphetamines elevate activity at DA synapses

Norepinephrine (NE)

Contributes to modulation of mood and arousal

Cocaine and amphetamines elevate the activity at NE synapses

SerotoninInvolved in regulation of sleep and wakefulness, eating and aggression

Abnormal levels may contribute to depression and OCD

Prozac and similar antidepressant drugs affect serotonin circuits

Gamma-aminobutyic acid

(GABA)

Serves as widely distributed inhibitory transmitter

Valium and similar antianxiety drugs work at GABA synapses

EndorphinsResemble opiate drugs in structure and effect

Contribute to pain relief and perhaps to some pleasurable emotions

The communication between cells is chemical.

More about that. . .

Lock and Key http://www.biologyinmotion.com/minilec/lock.html

Excitatory and Inhibitory Increases the likelihood that neuron will fire Decreases the likelihood that neuron will fire

Agonist and Antagonist A chemical that mimics the neurotransmitter A chemical that opposes the action of a neurotransmitter

Reuptake Process by which neurotransmitters are sponged up

from synapse by the presynaptic membrane

The Reflex Arc

Types of sensory receptors (get information from the environment). There are four types . . .

The simplest form of a behavior is called a reflex.

We need to know the basic types of neurons.

Mnemonic is SAME.

Take a look

HOW LONG DOES THIS TAKE?

ACTIVITY WITH REACTION TIME.

Fun with neurons

Fuzzy Neuron

Field Trip Preparation (look up terms)

Field Trip

AV The Mind #5 Endorphins

The Mind #5

Neuron 1:30

Fantastic Website!!!

http://www.g2conline.org/2022

3-D brain and neuron for explanation and study

The Brain

Structure and Function

Structure and Function

Structure and Function

Structure and Function

Structure and Function

Pinkie and the Brain

Organization of the Brain

How can we describe the brain?Neural tissue

description(the look)Location description(the

place)NAT GEO photo gallery

General divisions of the nervous system

Peripheral Nervous System (PNS)

Somatic Nervous SystemAutonomic Nervous System

Sympathetic Nervous System

Parasympathetic Nervous System

Central Nervous System (CNS)Spinal CordThe Brain

Reptilian BrainOld Mammalian BrainNew Mammalian Brain

(Neocortex)

Localization of function of the human brain

Structure and Function, Structure and Function

Subcortical areasStructure and FunctionStructure and FunctionStructure and Function

Neocortex

The look

The lobes

A review

Carl Sagen 11 mins

NAT GEO web site for review

Brain Surgery

Let’s Look Into Your Brain!

Today’s topics Right/Left Brain

Clip Dysfunctions

How do the two hemispheres of the brain communicate?

Lateralization of function of the human brain

Split Brain- although similarly located both cerebral hemispheres generally have similar functions, but. . .

There are some differences or lateralization of functions shown to exist

How did scientist figure this out???

Roger Sperry

According to Dr.Sperry, the brain has two hemispheres with different but overlapping functions. The right and left hemispheres of the brain each specialize in distinct types of thinking processes.

Left and Right Brain Specialization

http://www.nobelprize.org/educational/medicine/split-brain/index.html

How is this studied?

Electrical stimulation

PET scans

Cerebral vascular accidents (strokes), injury or lesioning Left/Right Side neglect

Split brain patients

Drugs affecting half of brain

Dichotic listening

Michael Gazzinga

Over the course of several decades, a major focus of his research has been an extensive study of patients that have undergone split-brain surgery that have revealed lateralization of functions across the cerebral hemispheres.

Split brain Paitent

Left Hemisphere Specialization

Speech and Language FunctionsWernicke’s AreaBroca’s AreaAngular gyrus

Contralateral representation

Right Hemisphere Specialization

Spatial Functions (patterns (gestalten), visual configurations, color discrimination)

Musical Functions

Contralateral Representation

The Brain

#6 Language and Speech

#7 Plasticity

#8 Visual Imaging Processing

Hemispheric Dysfunction

Broca’s Aphasia

Example (3 mins)

Wernicke’s Aphasia

example (4 mins)

Anomic Aphasia

Global Aphasia

Developmental Dyslexia

Plasticity

Chudler/plasticity

See Hand out

The Brain 7 mins

Windows to the Brain

Brain Imaging Techniques See Hand Out

Investigative Assignment Web search by Courtney Denton Plano ISD

Windows on the Brain

The Greeks

Franz Gall

Brain Damage – Phineas Gage

Lesion (ablation)

Imaging Techniques

The Greeks

Hippocrates460-377 BCEEmotions,

thought and mental health arise from the brain

Galen130-200 CEFluids in the

brain ventricles were responsible for sensations, reasoning, judgment and memories

57

Gall’s Contribution

58

American Phrenology Journal

59

Phineas Gage

A railroad construction worker in Vermont in 1848. Dynamite blew a tamper rod through his eye and out his skull. Remarkably, he survived, but was never the same. Once considerate and friendly, he was now overbearing and indecisive. Theory: executive control system in prefrontal cortex was damaged.

#25 Phineas Gage

Warren Museum Harvard Medical School Boston MA

Lesions Cutting of brain

tissue

Ablation – destroy brain tissue

(Essentially these are the same thing)

Do we do this today?

Some cool guys

Cajal

Golgi

Penfield

Hess

62

Golgi’s Contribution (1872)

63

Cajal’s Contribution: Discrete cells

Wilder Penfield Electrode into

brain to map motor cortex

1952

Walter Hess Electrode deeper

in brain to discover function of hypothalamus and “start-stop eating” function

1955

Brain Imaging Techniques

The are now many, highly specific methods to see into your brain.

Assignment to follow will help you discover the techniques used today.

As an introduction. . .

More modern approaches

EEG

CAT

MRI and fMRI

PET

MEG

SPECT

DTI

EEG

Transmit electrical activity (brain waves)

CAT or CT scan

Computerized axial tomography- computerized image of x-rays

MRI

Magnetic resonance imaging – magnetic field to develop image of the brain

fMRI

Functional MRI – detect the use of oxygen in the brain

PET

Positron emission tomography- slightly radioactive solution injected to see metabolic activity in imaged part of the brain

MEG

Magnetoencephalography- detect activity too brief to be detected by PET or MRI

SPECT

Single photon emission computerized tomography- tracks cerebral blood flow as an indicator of neural activity in a specific region of the brain

Diffusion Tensor Imaging

An MRI technique that measures the diffusion of water within a cell to yield an image of axons and neural tracts

Investigative Assignment

Brain Imaging and web search

Courtney Denton Plano ISD

Brain Dysfunction

http://www.ted.com/talks/jill_bolte_taylor_s_powerful_stroke_of_insight.html

Ted talks and strokes

The Endocrine System!!!!Chemical messengers telling

the body what to do

The Endocrine System

We rarely think about the endocrine system

However, it influences almost every cell, organ and function of our bodies

It is instrumental in regulating mood, growth and development, tissue functions, metabolism, sexual functions and reproductive processes

The Endocrine System

Integration and control is achieved through interaction of the nervous system with the endocrine system of glands that secrete chemical messengers called hormones.

Endocrine v. exocrine systems

Endocrine glands secrete “within” the body See remaining lecture notes

Exocrine glands secrete “outside” of the body Sweat glands Salivary glands Tear glands

A brief introduction

The endocrine system 3 mins

Comparison of endocrine and nervous system

Endocrine Glands

Secrete hormones directly into the blood stream

Endocrine transport may take minutes to hours

Endocrine effects are typically long lasting

BOTH interact with specific receptors on or in the target cells

Neurons (Nervous System)

Neurons transmit signals over neural networks (generally speaking)

Nervous control may take a fraction of a second to minutes

Neural effects are short lived

There is overlap between systems!!

The foundations of the endocrine system

Glands Hormones

Glands

A group of cells that produce and secrete chemicals

A gland selects and removes materials from the blood, processes them and secretes the finished chemical product for use somewhere in the body

Hormones – the chemical messengers of the body

3 typesSteroidsPeptides or proteinsAmino acid derivatives

Small amounts

Rapidly degraded

Specialized function of the endocrine glands

Pineal gland

Pituitary gland- Hypothalamus

Thyroid gland

Parathyroid gland

Adrenal gland

Pancreas

Ovaries and Testes

Discussion topics

How about synthetic hormones?

Hormonal disorders?