Bio Psych Week 2 Notes
Bio Psych Week 2 Notes Psych 383
Popular in Biological Psychology
Popular in Psychology
This 7 page Class Notes was uploaded by Maggie Loy on Wednesday September 28, 2016. The Class Notes belongs to Psych 383 at University of Wisconsin - Oshkosh taught by Dr. James Koch in Fall 2016. Since its upload, it has received 3 views. For similar materials see Biological Psychology in Psychology at University of Wisconsin - Oshkosh.
Reviews for Bio Psych Week 2 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/28/16
Bio Psych Week 2 Notes The Resting Potential: Why and How the Membrane is Polarized Check out p. 37 Ions to know: K+ = Potassium Cl = Chlorine Na+ = Sodium Ca+2 = Calcium + or – refers to positive or negative charge Diffusion: Wants to move ions from high to low concentration (seeking equilibrium) Electrostatic pressure (magnetism): Opposites attract and likes repel *Diffusion and EP can work together or balance each other out Maintaining and Resetting Resting Potential SodiumPotassium Pump (transport) Fig. 2.16! Balances out Receptors work the same way (for serotonin, dopamine, etc.) Make antipsychotics with this information The Action Potential Happens when the cell is depolarized to the threshold of excitation Neuron fires Threshold of excitation: Value of membrane potential that must be reached to produce an action potential (60 mV) Na+ and K+ ions cross the membrane through special pores Ion Channels When depolarization reaches certain point, they open up Different thresholds of opening Na+ opens first, then K+ Produces brief electrical impulse (change in polarization) Travels down axon to terminal button Causes release of chemical messengers Neurotransmitters, neuropeptides, neuromodulators Look for receptors to bind on same or other neurons *Fig 2.17 Ion Movement during the Action Potential Refractory period neuron isn’t supposed to be able to fire again; can be overcome 1. Threshold of excitation 2. Channels open, ions enter/leave cell 3. Refractory condition at peak of action potential 4. Resetting when the membrane potential returns to resting potential 5. Channels close/ reset Whole process takes 3 milliseconds *Study Fig. 2.17 – need to know each step and what happens! Conduction and Properties Action Potentials AllorNone Law: When an action potential is triggered, its size remains undiminished as it travels down the axon Rate of firing dependent on stimulus Rate Law: The strength of a stimulus is represented by the rate of firing of an axon Saltatory Conduction Action potential jumps from node of Ranvier to node of Ranvier Regenerated at each node In myelinated neurons Decremental conduction under myelin sheath Saves energy Fewer Na+/K+ pumps needed Increases speed Cable properties (decremental conduction) are very fast (120 m/s = 269 mph) 3. Communication between Neurons Synapses Use neurotransmitters (NTs) and receptors to transmit information from one neuron to another Presynaptic neuron releases NT and postsynaptic neuron has receptors to which NT binds NT binding to postsynaptic receptors either excites or inhibits postsynaptic neuron Neural Integration: Postsynaptic neuron integrates all incoming excitatory and inhibitory signals Excitation/inhibition both important for brain activity Neuron can synapse with: Another neuron Muscle cell (neuromuscular) Gland (neuroglandular) Types of synapses on neurons: Axodendritic Axon to dendrites (smooth part or on “spine”) Axosomatic Axon to soma Axoaxonic Axon to axon (or TB [terminal button] to TB, or axon to TB) Presynaptic facilitation (more NT release) Also: gap junctions Based on ion transfer Fig. 2.22 Details of a synapse *Learn vocabulary Microtubule Synaptic vesicle Pre/post synaptic membranes Release zone Post synaptic density Where receptors are located Synaptic cleft Release of NT **Know steps Undocked synaptic vesicle (free floating) Docking proteins Calcium channel Crucial Open when AP depolarize membrane Entry of calcium opens fusion pore “Omega” figures Diffusion What Happens After Release of NTs? NT released by neuron has several possible fates 1. Cross synaptic cleft and bind to postsynaptic receptor Ionotropic and metabotropic receptor Ionotropic (Fig. 2.26) only impact 1 ion channel per binding site Metabotropic (Fig. 2.27) wider influence, can impact multiple ion channels 1. NT binds to receptor 2. Gprotein activated 3. Gprotein subunits or intracellular messengers modulate ion channels 4. Ion channel opens (by intracellular messengers) 5. Ions flow across membrane Effector protein (Enzyme) Most commonly adenylate cyclase Binds with G protein subunit intracellular messenger cAMP (cyclic AMP) Produce postsynaptic potentials EPSP (Excitatory postsynaptic potential) = depolarization Positively charged ions come in IPSP (Inhibitory postsynaptic potential)=hyperpolarization Positively charged ions leave Negatively charged ions come in Valium for example connects to channels Alcohol deactivate motor neurons Neural integration IPSP can counteract EPSP action potential not triggered in axon EPSPs or IPSPs result from movement of ions across membrane Outside to inside (Na+, Cl, Ca+2) Inside to outside (K+) 2. Bind to auto receptors Receptors on the same neuron that NT is released from Located on any part of neuron (TB & dendrites) Monitor amount of NT (activation= less release of NT) Presynaptic autoreceptors or somatodendritic autoreceptors Slow down release 3. Bind to reuptake pumps (transporter) and get back inside TB Drugs also have reactions at reuptake pumps Cocaine blocks it Ecstasy reverses movement in reuptake pump 4. Enzyme deactivation in synapse Enzyme breaks up NT AchE & Acetylcholine 5. Diffuse away Recycling of synaptic vesicle membrane (Fig. 2.25) Kiss and run Releases and pinches off – goes back in Merge and recycle Merges with membrane itself – goes back in Bulk endocytosis Pinches off Pools of NT in TB 1. Ready release Docked and ready to release NT 2. Recycle 3. Reserve Chemical Communication Neurotransmitters: from TB Small amount Local (to receptor on one neuron across synapse) Pools of NTs Ready release (1%) Recycling (1015%) Reserve (8590%) Neuromodulators: from TB Larger amount Travel farther (to many neurons in an area) Wider influence Peptides (e.g. endorphins) Hormones: from endocrine glands (nonsynaptic) Travel farther: via bloodstream (circulatory system rather than nervous) Affect many types of “target” cells E.g. steroid hormones Penetrate nucleus and attach to receptors (affects protein synthesis) Fig. 2.32 Too much impacts gene expression Neuroanatomy What we will be learning: Organization: How it’s laid out Names: Memorization Relative location: What’s next to what Interconnections: What’s hooked up to what Dealing with many circuits of neurons Nucleus in CNS Group of functionally & structurally similar neuron Crossed systems Left/right side of brain Where neurons cross over Contralateral = other side Ipsilateral = same side Function: How neuroanatomy is related to behavior Nervous system Central (CNS) Brain and spinal cord Brain Forebrain Midbrain Hindbrain Each divided into “encephalons” (lobes) Meninges Layers to protect brain Ventricles Fluid filled spaces Produce CSF Filter stuff out into blood stream Sulcus (sulci) = groove Fissure = large sulci Gyrus = fold/hump Peripheral (PNS) 1. Somatic: spinal and cranial nerves Bring info into CNS (sensory) Move muscles (motor) 2. Autonomic Sympathetic Heart rate rise Parasympathetic Energy balance: use & storage Heart rate decrease Planes of Section Frontal (transverse brain) Front and back halves Horizontal Top and bottom halves Sagittal Right and left halves Transverse (Cross section) Spinal cord horizontal Anatomical Directions Neuraxis in humans is curved Rostral or anterior = top Caudal or posterior = bottom Dorsal = back or top of head Ventral = front or bottom of head Lateral = away from midline Medial = toward midline Brain & SC coverings = Meninges Dura mater Outermost Hard and protective Arachnoid membrane Weblike Contains CSF Subarachnoid space Arachnoid trabeculae look like pillars Pia mater Soft Follows convolutions
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'