If I only had a brain – Wizard of Oz

Biological Bases of Behavior “The brain is the last and greatest biological frontier. It is the most complex thing we have yet discovered in the universe.”

Hippocrates (400 BC) “From the brain and only the brain arise our pleasures, joys, laughter and jests,as well as our sorrows, pains, grief and tears.”

Biological Bases of Behavior “It’s amazing to think that the body feeds the brain sugar and amino acids and what comes out is poetry and piroettes.” “It’s amazing to think that the body feeds the brain sugar and amino acids and what comes out is poetry and piroettes.” -Neuroscientist Robert Collins (1997) -Neuroscientist Robert Collins (1997)

“Decade of the Brain” President George Bush “…to enhance public awareness of the benefits to be derived from brain research…”

2013 B.R.A.I.N. Initiative ($110 mil)

1809 Phrenology: Francis Gall Traits=bumps Traits=bumps Bump=more brain tissue Bump=more brain tissue Pseudoscience Pseudoscience Brain? Localization of function—yes. Brain? Localization of function—yes. Cranial bumps? Wrong. Cranial bumps? Wrong.

Searching for the biology of “self” 8 Is our identity in the heart? In the brain? In the whole body?

Physiological Psychology n Study of... Brain & nervous system – Their relation to psychological things…. ThoughtEmotion Behavior

Physiological Psychology n Biopsychology –Broader field n Neuroscience –Study of brain-behavior link Clinical Neuroscience Clinical Neuroscience Cognitive Neuroscience Cognitive Neuroscience Affective Neuroscience Affective Neuroscience n Neuropsychology –Assessment of brain functioning

Surveying the Chapter: Overview What We Have in Mind  Building blocks of the mind: neurons and how they communicate (neurotransmitters)  Systems that build the mind: functions of the parts of the nervous system  Supporting player: the slower- communicating endocrine system (hormones)  Star of the show: the brain and its structures

Information-processing 1) Encode (translate) 2) Organize & integrate 3) Respond 4) Self-monitor Self-awareness Self-awareness Meta-cognition Meta-cognition

©2001 Prentice Hall The Neuron

n Neuron = a cell specialized to receive, process, and/or transmit a signal specialized to receive, process, and/or transmit a signal n Nerve = bundle of axons (from many neurons) = bundle of axons (from many neurons)

Nerve: a bundle of axons Nerve: a bundle of axons

The Neuron (a single cell)

3 Types Neurons n Sensory neurons sense receptors --> CNS n Motor neurons CNS --> muscles and glands n Interneurons sensory --> interneurons-->motor

Spinal Reflex: Pain Withdrawal

The Neural Impulse: Electrochemical Beginnings n Hodgkin & Huxley (1952) - giant squid n Fluids inside and outside neuron n Electrically charged particles (ions) n Neuron at rest – negative charge on inside compared to outside n -70 millivolts – resting potential 19

The Neuron Copyright 2002 Allyn & Bacon SOMA AXON Dendrites Terminal Buttons RECEIVE SEND

Neurons and Neuronal Communication: The Structure of a Neuron There are billions of neurons (nerve cells) throughout the body.

The Neural Impulse Neural impulse Brief electric surge that carries the neuron’s message Ions Charged particles that move through the cell membrane

“Resting Potential” n ions (+sodium atoms, -chloride atoms, +potassium atoms) n ion channels along cell membrane n semi-permeable membrane n membrane has a sodium pump n Resting= -70 millivolts n Resting= -70 millivolts (1/20 of flashlight battery)

The Action Potential n the firing of a single neuron n ion channels fly open n rapid cascade of voltage change runs down membrane n all-or-nothing phenomenon

Action potential: a neural impulse that travels down an axon like a wave Just as “the wave” can flow to the right in a stadium even though the people only move up and down, a wave moves down an axon although it is only made up of ion exchanges moving in and out.

All-or-none law Size of action potential not affected by increases in stimulation beyond threshold Size of action potential not affected by increases in stimulation beyond threshold

Action Potential

The neuron receives signals from other neurons; some are telling it to fire and some are telling it not to fire.  When the threshold is reached, the action potential starts moving.  Like a gun, it either fires or it doesn’t; more stimulation does nothing.  This is known as the “all-or- none” response.  When the threshold is reached, the action potential starts moving.  Like a gun, it either fires or it doesn’t; more stimulation does nothing.  This is known as the “all-or- none” response. The action potential travels down the axon from the cell body to the terminal branches. The signal is transmitted to another cell. However, the message must find a way to cross a gap between cells. This gap is also called the synapse. How neurons communicate (with each other): When does the cell send the action potential?... when it reaches a threshold The threshold is reached when excitatory (“Fire!”) signals outweigh the inhibitory (“Don’t fire!”) signals by a certain amount.

©2001 Prentice Hall Synaptic Transmission

n Synapse the synapse (noun) the synapse (noun) to synapse (can be verb too) to synapse (can be verb too) n Neurotransmitters Chemical messengers across the synaptic cleft Chemical messengers across the synaptic cleft

The synapse is also known as the “synaptic junction” or “synaptic gap.” The Synapse The synapse is a junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.

Synapse

Neurotransmitters Neurotransmitters are chemicals used to send a signal across the synaptic gap.

Hearing the message How Neurotransmitters Activate Receptors When the key fits, the site is opened.

Reuptake: Recycling Neurotransmitters [NTs] Reuptake: After the neurotransmitters stimulate the receptors on the receiving neuron, the chemicals are taken back up into the sending neuron to be used again.

Keys that almost fit: Agonist and Antagonist Molecules An antagonist molecule fills the lock so that the neurotransmitter cannot get in and activate the receptor site. An agonist molecule fills the receptor site and activates it, acting like the neurotransmitter.

1. Synthesis 2. Release 3. Binding 4. Deactivation 5. Reuptake 5 Stages of Synaptic Transmission

Synapse

Hearing the message How Neurotransmitters Activate Receptors When the key fits, the site is opened.

Neurotransmitters AcetylcholineGlutamateGABADopamineNorepinephrineSerotoninEndorphins

Some Neurotransmitters and Their Functions NeurotransmitterFunctionProblems Caused by Imbalances Roles of Different Neurotransmitters SerotoninAffects mood, hunger, sleep, and arousal Undersupply linked to depression; some antidepressant drugs raise serotonin levels DopamineInfluences movement, learning, attention, and emotion Oversupply linked to schizophrenia; undersupply linked to tremors and decreased mobility in Parkinson’s disease and ADHD Acetylcholine (ACh) Enables muscle action, learning, and memory ACh-producing neurons deteriorate as Alzheimer’s disease progresses NorepinephrineHelps control alertness and arousal Undersupply can depress mood and cause ADHD-like attention problems GABA (gamma- aminobutyric acid A major inhibitory neurotransmitter Undersupply linked to seizures, tremors, and insomnia GlutamateA major excitatory neurotransmitter; involved in memory Oversupply can overstimulate the brain, producing migraines or seizures; this is why some people avoid MSG (monosodium glutamate) in food

Keys that almost fit: Agonist and Antagonist Molecules An antagonist molecule fills the lock so that the neurotransmitter cannot get in and activate the receptor site. An agonist molecule fills the receptor site and activates it, acting like the neurotransmitter.

MDMA (Ecstacy)

n Binds to serotonin transporters n Increases serotonin n Modulates release of dopamine and norepinephrin n Modulates release of oxytocin and vassopressin (love )  Causes high levels of serotonin, dopamine, and norepinephrin  Causes high levels of serotonin, dopamine, and norepinephrin

MDMA: Is it safe? Controversial finding 1990s research by John Hopkins U Scary results:

A leading scientific journal yesterday retracted a paper it published last year saying that one night's typical dose of the drug Ecstasy might cause permanent brain damage. The monkeys and baboons in the study were not injected with Ecstasy but with a powerful amphetamine, said the journal, Science magazine.

2014 Review

CONCLUSION “…Deficits have been demonstrated in retrospective memory, prospective memory, higher cognition, complex visual processing, sleep architecture, sleep apnea, pain, neurohormonal activity, and psychiatric status. Neuroimaging studies have shown serotonergic deficits, which are associated with lifetime Ecstasy /MDMA usage, and degree of neurocognitive impairment. Basic psychological skills remain intact. Ecstasy/MDMA use by pregnant mothers leads to psychomotor impairments in the children. Hence, the damaging effects of Ecstasy/MDMA were far more widespread than was realized a few years ago. In summary, MDMA can induce a wide range of neuropsychobiological changes, many of which are damaging to humans.

Some Neurotransmitters and Their Functions NeurotransmitterFunctionProblems Caused by Imbalances Roles of Different Neurotransmitters SerotoninAffects mood, hunger, sleep, and arousal Undersupply linked to depression; some antidepressant drugs raise serotonin levels DopamineInfluences movement, learning, attention, and emotion Oversupply linked to schizophrenia; undersupply linked to tremors and decreased mobility in Parkinson’s disease and ADHD Acetylcholine (ACh) Enables muscle action, learning, and memory ACh-producing neurons deteriorate as Alzheimer’s disease progresses NorepinephrineHelps control alertness and arousal Undersupply can depress mood and cause ADHD-like attention problems GABA (gamma- aminobutyric acid A major inhibitory neurotransmitter Undersupply linked to seizures, tremors, and insomnia GlutamateA major excitatory neurotransmitter; involved in memory Oversupply can overstimulate the brain, producing migraines or seizures; this is why some people avoid MSG (monosodium glutamate) in food

Serotonin pathways Networks of neurons that communicate with serotonin help regulate mood. Networks of neurons that communicate with dopamine are involved in focusing attention and controlling movement. Dopamine pathways

Receptor Binding Affinities for LSD Serotonin Dopamine Norepinephrin

The Inner and Outer Parts of the Nervous System The central nervous system [CNS] consists of the brain and spinal cord. The CNS makes decisions for the body. The peripheral nervous system [PNS] consists of ‘the rest’ of the nervous system. The PNS gathers and sends information to and from the rest of the body.

The “Nerves” are not the same as neurons. Nerves consist of neural “cables” containing many axons. Nerves are part of the peripheral nervous system and connect muscles, glands, and sense organs to the central nervous system.

More Parts of the Nervous System

The Peripheral Nervous System

The Autonomic Nervous System: The sympathetic NS arouses (fight-or-flight) The parasympathetic NS calms (rest and digest)

The Central Nervous System  The brain is a web of neural networks.  The spinal cord is full of interneurons that sometimes have a “mind of their own.”

Endocrine System Network of glands Hormones Chemical messangers.. Hormones  Metabolism: HUNGER, THIRST  Growth hormone  Motivation: SEX, AGGRESSION  Stress reactions: FIGHT OR FLIGHT

The Endocrine System The endocrine system refers to a set of glands that produce chemical messengers called hormones.

The Body’s “Slow but Sure” Endocrine Message System  bloodstream  bloodstream instead of synapses.  molecules as messages  Molecules, called hormones  produced in glands around body.  messages go to the brain and other body tissues.

1.The sympathetic “fight or flight” nervous system adrenal glands 2.Responds to stress by sending message to adrenal glands 3.Release stress hormones Effect?  heart rate,  blood pressure,  blood sugar. ENERGY  fight or flight! Adrenal Glands Pancreas Adrenal Glands Adrenaline (Epinephrine) Noradrenaline (Norepinephrine) Cortisol

The Pituitary Gland  master gland” of the endocrine system.  Controlled by hypothalamus  Secretes hormones that regulate other glands  Growth Hormone (especially during sleep)  Oxytocin “bonding” hormone Pituitary gland

Endocrine System