PSYC 260 1st EditionExam # 3 Study Guide Lectures: 15-22Exam 3 Study GuideChapter 5-Otto Loewi: he discovered Acetylcholine-Postsynaptic Potentials1. Excitatory Postsynaptic Potentials (EPSPs)- brief depolarization of a neuron membrane in response to stimulation, making the neuron more likely to produce an action potential2. Inhibitory Postsynaptic Potential (IPSPs)- brief hyperpolarization of a neuron membrane in response to stimulation, making the neuron less likely to produce an action potential -Neurotransmitter: chemical released by a neuron onto a target with an excitatory or inhibitory effect.-Acetylcholine (Ach): First neurotransmitter discovered in the CNS and PNS. Activates skeletal muscles in the somatic nervous system and can excited or inhibit organs in the autonomic nervous system-Epinephrine (EP): chemical messenger that acts as a hormone to mobilize the body for fight or flight during times of stress and as a neurotransmitter in the CNS (AKA- ADRENALINE) -Norepinephrine (NE): neurotransmitter found in the brain and in the nervous system; accelerate heart rate in mammals-Chemical Synapses:-Synaptic Cleft: gap that separate the presynaptic membrane from the postsynaptic membrane-Synaptic Vesicle: Organelle consisting of a membrane structure that encloses and carries a neurotransmitter- Glial cells act to clean up all of the excess chemicals left in space, and they also provide some chemicals to the neuron, which will be used to build new neurotransmitters-Electrical Synapses:-Gap Junction (Electrical Synapse): Fused junction cell membrane in which connected ion channels form a pore that allows ions to pass directly from one neuron to the next-Steps of Neurotransmission:1. Neurotransmitters must be synthesized and stored in the axon terminal-Derived in 2 ways:A. Synthesized in the cell body (via DNA), packed in Golgi bodies and transported on microtubules to the terminal button.B. Or, synthesized in the terminal button itself, built from building blocks derived from food via transporters (protein molecule that pumps substances across a membrane). The storage granules hold several vesicles. 2. The neurotransmitter must be transported to the presynaptic membrane and released in response to an action potential (see notes for more details)3. The neurotransmitter must be able to activate the receptors on the target-cell membrane located on the postsynaptic membrane-Transmitter-activated receptors- proteins with binding sites for specific neurotransmitters and is embedded in the membrane of a cell-Autoreceptors- “self-receptor” in a neural membrane that responds to the neurotransmitter of the neuron it belongs to.-Quantum- amount of neurotransmitter, equivalent to the contents of a single synaptic vesicle that produces a just observable change in postsynaptic electric potential. It takes several quanta to produce an action potential4. The neurotransmitter must be activated, or its effects will last forever-Deactivation1. Diffusion- neurotransmitter diffuses away2. Degradation- enzymes in the synaptic cleft break them down (similar to the game red rover)3. Reuptake- presynaptic membrane transporter proteins bring the transmitter back into the presynaptic axon terminal for subsequent reuse4. Glial uptake- neighboring glial cells take up the transmitter and store it for reintroduction to axon terminal -Types of Synapses:-Axomuscular: axon synapses with a muscle end plate (acetylcholine)-Axondendritic: axon terminal and dendrites-Dendrodendritic: dendrites send messages to other dendrites-Axondendritic: axon terminal of one neuron synapse on the dendritic spine of another (same as axodendritic) -Axonextracellular: axon terminal with no specific target. Secretes transmitter into extracellular fluid-Axosomatic: axon terminal ends on cell body-Axosynaptic: axon terminal ends on another axon terminal-Axoaxonic: axon terminal ends on another axon-Axosecretory: axon terminal ends on a blood vessel and secretes its transmitter directly into the blood-Types of Messages:-Excitatory: Type I synapse; typically furthest from axon hillock-Inhibitory: Type II synapse; Typically furthest from axon hillock; can act as a defense against excitatory signals-Identifying Neurotransmitters:1. The chemical must be synthesized in the neuron or otherwise present in it (build it, store it, make it exist)2. When the neuron is active, the chemical must be released and produce response on some target3. The same response must be obtained when the chemical is experimentally placed on a target4. A mechanism must exist from removing the chemical from its site of action after its work is doneClasses of Neurotransmitters:1. Small-molecule transmitters2. Peptide transmitters3. Transmitter gasesClasses of Receptors:-Ionotropic receptors: embedded membrane protein acts as (1) a binding site for a neurotransmitter and (2) a pore/gate that regulates ion flow to directly and rapidly change membrane voltage-Metabotropic receptor: embedded membrane protein, with a binding site for a neurotransmitter but nopore. They are linked to a G protein that can affect other receptors or act with second messengers to affect other cellular processesNeurotransmitters in SNS-Motor neurons in the brain and spinal cord have axons that reach the body’s skeletal muscles, making behavior possible-Acetylcholine-Ionotropic receptorsNeurotransmitters in ANS1. Sympathetic (fight-flight)a. Norepinephrine receptors2. Parasympathetic (rest-digest)a. Acetylcholine receptorsThe 4 Activating Systems of the CNS1. Cholinergic System2. Dopaminergic System3. Noradrenergic System4. Serotonergic System-Learning: a relatively permanent change in behavior that results from experience-Hepp Synapse: idea that when you have enough instances of relationship established between pre and postsynaptic potential…(full quote in book)2 Kinds of Learning1. Habituation a. Learning behavior in which a response to a stimulus weakens with repeated stimuluspresentations2. Sensitizationa. Learning behavior in which the response to a stimulus strengthens with repeated presentations of that stimulus because the stimulus is novel or because the stimulus is stronger than normalChapter 8-Three perspectives on the brain development1. Structural development can be studied and correlated with the emergence of behavior2. Behavioral development can be analyzed and predictions made about what underlying circuitry must be emerging3. Factors that influence both brain