* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download File
Neuroregeneration wikipedia , lookup
Neural oscillation wikipedia , lookup
Premovement neuronal activity wikipedia , lookup
NMDA receptor wikipedia , lookup
Metastability in the brain wikipedia , lookup
Activity-dependent plasticity wikipedia , lookup
Multielectrode array wikipedia , lookup
Caridoid escape reaction wikipedia , lookup
Node of Ranvier wikipedia , lookup
Holonomic brain theory wikipedia , lookup
Axon guidance wikipedia , lookup
Optogenetics wikipedia , lookup
Mirror neuron wikipedia , lookup
Neural coding wikipedia , lookup
Membrane potential wikipedia , lookup
Signal transduction wikipedia , lookup
Development of the nervous system wikipedia , lookup
Feature detection (nervous system) wikipedia , lookup
Action potential wikipedia , lookup
Endocannabinoid system wikipedia , lookup
Resting potential wikipedia , lookup
Electrophysiology wikipedia , lookup
Pre-Bötzinger complex wikipedia , lookup
Neuroanatomy wikipedia , lookup
Neuromuscular junction wikipedia , lookup
Channelrhodopsin wikipedia , lookup
Synaptogenesis wikipedia , lookup
Nonsynaptic plasticity wikipedia , lookup
Single-unit recording wikipedia , lookup
Clinical neurochemistry wikipedia , lookup
Synaptic gating wikipedia , lookup
End-plate potential wikipedia , lookup
Biological neuron model wikipedia , lookup
Chemical synapse wikipedia , lookup
Nervous system network models wikipedia , lookup
Stimulus (physiology) wikipedia , lookup
Molecular neuroscience wikipedia , lookup
AGONISTS E FFECTS • • • • ANTAGONISTS OF DRUGS ON N.S. • Block actions of Mimic actions of neurotransmitters neurotransmitters Occupy receptor site & Bind to receptors & prevent action. generate PSP’s A molecule, that by binding A molecule that, by to a receptor site, inhibits or binding to a receptor blocks a response site, stimulates a Botulin (poison found in response improperly canned food causes Opiate drugs can paralysis by blocking ACh release produce a temporary We call it Botox and inject it into “high” our faces to paralyze underlying facial muscles BIOLOGICAL PSYCHOLOGY AND NEUROTRANSMISSION WHY STUDY BIOLOGY IF THIS CLASS IS CALLED PSYCHOLOGY?? Everything psychological is simultaneously biological. To think, feel or act without a body would be like running without legs. -We are bio-psycho-social systems. To understand our behavior, we need to study how biological, psychological and social systems interact. The human brain is the most complex system, natural or man made, in the world. About 3 lbs. About the size of a grapefruit Pinkish/gray in color About 100 billion nerve cells At a loss rate of 200,000 per day during our adult lives we still end up with over 98% of or brain cells. Biopsychology: The specialty in psychology that studies the interaction of biology, behavior and mental processes. -The mind thinking about the mind . some biological psychologists call themselves behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists Neuroscience is a newer field of study in psychology focusing on the brain and our behavior. PHRENOLOGY Back in the olden days, we believed many very stupid and silly things about humans and our minds (cough…hindsight bias..) One of those things was phrenology - the believed that studying bumps on the skull could reveal your mental abilities and skills. BIOLOGICAL PSYCHOLOGISTS Today, we now rely on biological psychologists (people who study the links between biological [genetic, neural, hormonal] and psychological processes) NEURONS NEURONS ARE SUPER COOL A specialized cell that receives information and transmits it to other cells Individual nerve cells that receive, integrate, and transmit information The basic elements of communication in the nervous system, but only the majority communicate with other neurons. However, there are some exceptions Approx. 100 billion neurons make up the brain Millions of neurons are involved in producing a single thought A “T YPICAL” NEURON GLIA Cells found throughout the nervous system that provide various types of support for neurons Outnumber neurons 10-1, 50% of the brains volume Nourish neurons Remove waste products Insulation The heroes of the nervous system THE CHARGE INSIDE THE NEURON IS NEGATIVE Resting potential ● The imbalanced electrical charge of the axon in its inactive state (when the neuron is ready to fire) oThe inside of cell is negative relative to the outside of the axon POLARIZATION DURING RESTING POTENTIAL the neuron is polarized = opposites of each other. inside of a neuron’s charge is all NEGATIVE Outside of a neuron, the charge is POSITIVE Negatives w/negatives, positives w/positives. “Happy homeostasis” prefers to be this way. NEURON AT REST Inside and outside the neuron are fluids containing electrically charged atoms and molecules called “ions” Positively charged potassium and sodium and negatively charged chloride ions flow back and forth across the cell membrane, but do NOT cross at the same rate HIGHER CONCENTRATION of negatively charged ions inside the cell------ resulting voltage/potential energy RESTING POTENTIAL- stable, negative charge when the cell is inactive (-70 million volts) How Does it Work? Neurotransmission is a fancy name for two or more neurons communicating with each other. There are 4 neurons communicating in the picture to the right or you could say that neurotransmission is taking place 1 3 4 2 Neurons stay at rest with their sodium ions on the outside of the cell body (or soma) and potassium ions on the inside. Neurons are no longer at rest when the sodium ions on the outside of the cell body rush in and potassium ions on the inside rush out. The typical neuron receives hundreds of messages…some of these messages are excitatory (saying “FIRE”) while others are inhibitory (saying “DON’T FIRE”) e e i e e e e e e i i e i When there are more excitatory than inhibitory messages, the cell body exceeds its threshold (level of stimulation required to trigger the impulses) and creates an electric impulse… This is called ACTION POTENTIAL Action potential An electrical impulse is caused from the rushing in and out of the ions (depolarization) Most basic – electrical charge that travels through the axon of the neuron; the message that travels through the axon of the neuron. At that moment, the charge becomes less negative/even positive, creating an action potential Action potential is the DEPOLARIZATION of a NEURON Depolarization occurs, when positive sodium (Na+) ions enter the neuron, making it more susceptible to fire an action potential. Neuron no longer @ homeostasis—domino effect. Once the electrical impulse reaches the terminal button it triggers the vesicles (containing neurotransmitters), to move toward the bottom of the terminal button. REFRACTORY PERIODS After all this excitement, the channels in the cell membranes will close up again (and this may take some time) Refractory Period After a neuron has fired an action potential it pauses for a short period to recharge itself to fire again – at this time the inside potassium ions move out of the cell & cannot fire Like a toilet bowl..gotta wait for the water to fill up again. Imagine running a sprint. After you finish running, you will need a period of time (ARP) to calm down before you will run again. After you completely recover, you can run again, but you will need some more intense motivation (RRP), because you don’t really feel like sprinting again. Other Action Potential Info… This graph depicts the change, with time, in the electrical charge across a given point on the axon membrane as an action potential passes through that point. To transmit the “message” the length of the axon takes less than one hundredth of a second!! With each action potential, a small amount of sodium enters the cell and a small amount of potassium leaves it – to maintain the original balance of these elements, each portion of the axon has a sodium-potassium pump that continuously moves sodium out of the cell and potassium into it http://highered.mheducation.com/sites/0072943696/student_view0/chapter8/animation__transmission_acr oss_a_synapse.html Synapse -- a junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. This tiny gap is called the synaptic gap or cleft. Axon Terminal buttons creates NEUROTRANSMITTERS. Go into gap, and received (from receptor sites) on dendrites. Create electrical impulse for the neuron. All in 1/100th of a second! SYNAPTIC CLEFT & NEUROTRANSMITTERS Neurons don’t actually touch Synaptic Cleft-microscopic gap between the terminal button of one neuron and the cell membrane of another neuron This gap must be jumped in order for neurons to communicate Presynaptic neuron- sends signal Postsynaptic neuron- receives signal How does this happen? The arrival of an action potential at an axon’s terminal triggers the release of NEUROTRANSMITTERS- chemicals that transmit information from one neuron to another Collected together in little sacks called SYNAPTIC VESICLES Vesicles fuse together with the membrane and spill contents into the synaptic gap They may bind to certain areas at various receptor sites ALL-OR-NONE (PRINCIPLE) LAW The neural impulse is like a toilet, either it fires or it doesn’t fire Action potentials are all the same size as well Neurons convey information about the strength of a stimulus by varying the rate at which they fire action potentials Stronger stimulus- more rapid volley of neural impulses than a weaker stimulus FLUSHING NEURON-CAT Write these out on a separate sheet of paper (label and EXPLAIN) All-or-Nothing Principle Refractory Period Resting Potential Action Potential Dendrites Axon Myelin Sheath Terminal Buttons Soma Watch the cat again, however this time, watch it and imagine that the toilet flushing is like a neuron firing https://www.youtube.com/watch?v=H2W8XKK -3Rk&feature=youtu.be NEUROTRANSMITTERS Neurotransmitters (chemicals) released from the sending neuron, travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing it to generate an action potential. OCD High blood pressure Neurotransmitters bind to the receptors of the receiving neuron in a key-lock mechanism. Each neurotransmitter has an unique chemical configuration… Neurotransmitters attach to specific receptors…like a puzzle piece fitting into its proper place, receptors will only accept or recognize one type of neurotransmitter NEUROTRANSMITTERS ACETYLCHOLINE Acetylcholine (often abbreviated ACh) is the most common neurotransmitter. It is located in both the central nervous and peripheral nervous system Acetylcholine was the first neurotransmitter be identified in 1914 As a neuromodulator it acts on basic autonomic and muscular fuctions Sarin Gas disrupts its ability to function and often leads to death Neurotransmitters Dopamine Generally involved in regulatory motor activity In the basal ganglia, involved in mood, sensory perception, and attention NEUROTRANSMITTERS Glutamate Is an excitatory neurotransmitter Plays a role in learning and memory Too much can cause seizures Malfunction of glutamate has also been associated with Alzheimer's’ NEUROTRANSMITTERS Epinephrine Also known as adrenaline Causes the feeling of being “revved up” or on edge Activates a “fight or flight” reaction in the autonomic nervous system NEUROTRANSMITTERS Serotonin Attention and other complex cognitive functions, such as sleep (dreaming), eating, mood, pain regulation Neurons which use serotonin are distributed throughout the brain, stomach and spinal cord Mood disorders NEUROTRANSMITTERS GABA (gamma-aminobutyric acid) GABA is the most important and common inhibitory neurotransmitter Stops the brain from becoming overexcited Too much may cause hallucinations AGONISTS E FFECTS ANTAGONISTS OF DRUGS ON N.S. Block actions of neurotransmitters Mimic actions of Occupy receptor site & neurotransmitters prevent action. Bind to receptors & a molecule, that by binding generate PSP’s to a receptor site, inhibits or a molecule that, by blocks a response binding to a receptor Botulin (poison found in site, stimulates a improperly canned food) causes response paralysis by blocking ACh Opiate drugs can release produce a temporary We call it Botox and inject it into our faces to paralyze underlying “high” • • • • • facial muscles Outside substances, that mimic (Fit) into receptor site for neurotransmitter Similar enough in structure that it mimics the neurotransmitters effect on the receiving neuron – often agonists INCREASE activity by inhibiting reputake Sends message over and over again! (Drugs and effectiveness) “Master Key” Similar enough to occupy the receptor site and block its action, but not similar enough to stimulate activity “Other Key”