Psyc 260 fa24 04 intro to neurons and neural communication (edited) (1).pdf

Intro to Neurons and Neural Communication PSYC 260 Fall 2024 lecture 4 TPS 4A: Review questions 1. A researcher is interested in the relationship between maternal stress and the stress of their offspring. Pregnant rats are either put in highly stressful situations, or...

Intro to Neurons and Neural Communication PSYC 260 Fall 2024 lecture 4 TPS 4A: Review questions 1. A researcher is interested in the relationship between maternal stress and the stress of their offspring. Pregnant rats are either put in highly stressful situations, or not put in them. After the baby is born, the stress response of the offspring is measured. What is the independent variable? What is the dependent variable? 2. Damage to Broca’s area impairs speech production but not comprehension. Damage to Wernicke’s area has the opposite effect. This pattern is considered the gold standard in neuropsychology and is called a(an) ______________. 3. Which has higher temporal (time based) resolution, event-related brain potentials (ERP) or functional magnetic resonance imaging (fMRI)? Attendance Learning Objectives Recognize the difference between neurons and glial cells Recognize the parts of a neuron (soma, dendrites, dendritic spines, axon hillock, axon, terminal buttons/axon terminals, myelin sheath) and the function of those parts Recognize what a synapse is and the difference between a presynaptic and a postsynaptic neuron Identify and distinguish between key components of neural communication (action potential, neurotransmitters, inhibition and excitation, summation, membrane potential, threshold of excitation)  Brief history of the neuron Camillo Golgi In 1873 discovered a way to stain cells to see their structure Santiago Ramón y Cajal Applied Golgi stains to brain cells and discovered that the brain was made up of many individual cells separated by tiny gaps. Neuron doctrine – neurons (individual cells) are the basic signaling units of the nervous system Central and Peripheral Nervous System Nerve impulses are signals sent between neurons in the central and peripheral nervous system Neurons & Glia Neurons – cells in the nervous system that send and receive information Together, they form a computational system that allows us to experience the world as we know it. Neuron Doctrine: Glia – cells of the nervous system that are not neurons Many types provide physical and metabolic support for neurons Neurons come in many shapes and sizes Glial Cells Neural Communication Neurons communicate using electrical and chemical signals Action potentials: electrical signals within the neuron Neurotransmitters: chemical signals between neurons Synapse or synaptic gap (small space between neurons) Presynaptic neuron Postsynaptic neuron (sends signal) (receives signal)  Dendrites – lined with synaptic receptors (spines) for receiving signals from other neurons Cell body (Soma) – contains the nucleus and does most of the metabolic processes like dendrites, it has synaptic receptors Axon – Action potentials (electric signals) travel down the axon to communicate with the Axon hillock – where the computations (decisions to fire and action potential) occur Myelin sheath – insulation on the axon Presynaptic terminals (axon terminals)– releases neurotransmitters (chemical signals) across the synaptic gap between neurons The neurotransmitters bind to receptors on the post- synaptic (receiving) neuron, making it more or less likely to fire an action potential TPS 4B: label the diagram 1. the branches 2. 3. the insulation part 4.the long fiber 5. the tips 6. the part connecting the long fiber 8. the bumps 7. on the branches Action potentials Electrical signals that travel down the axon. An action potentials ends with the release of neurotransmitters that influence the next neuron (or muscle) Neurons send neurotransmitters (chemical signals) across the synaptic gaps presynaptic (sending) neuron postsynaptic (receiving) neuron Neurotransmitters excite or inhibit the postsynaptic (receiving) cell Summation (adding) of EPSPs and IPSPs EPSP: Excitatory post synaptic potential IPSP: Inhibitory post synaptic potential If the sum reaches the threshold of activation, the postsynaptic cell will “fire” an action potential down its axon TPS4 B Neural communication involves excitation (to increase firing of action potentials) and inhibition (to decrease firing) The brain processes information. It receives input (environmental energy), transforms it in relationship to our memory (innate and learned memories), and outputs it in the form of behavior. Why would excitation be useful for sending information throughout the brain? Why would inhibition be useful? Midterm Review Questions: MRQ 4 write two multiple choice questions that you think would help in studying / prepping for the midterm. You are encouraged to write questions that relate to the learning objectives of the lecture This should be done when we get to the end of every lecture, even if we don’t have time to do them in class (then they become homework)