PSB Exam 1 Notes PDF

Chapter 1: Basic Concepts and Neuroanatomy 1.​ Neuron Doctrine ○​ Proposed by Santiago Ramón y Cajal, states that the brain is composed of discrete cells (neurons) that communicate via synapses. 2.​ Broca & Wernicke ○​ Broca's Area: Located in the left frontal l...

Chapter 1: Basic Concepts and Neuroanatomy 1.​ Neuron Doctrine ○​ Proposed by Santiago Ramón y Cajal, states that the brain is composed of discrete cells (neurons) that communicate via synapses. 2.​ Broca & Wernicke ○​ Broca's Area: Located in the left frontal lobe; associated with speech production. Damage results in Broca's aphasia (difficulty forming speech). ○​ Wernicke's Area: Located in the left temporal lobe; associated with language comprehension. Damage results in Wernicke's aphasia (difficulty understanding speech). 3.​ Somatic and Behavioral Variables ○​ Somatic variables: Physical structures or functions of the body (e.g., brain size, neural activity). ○​ Behavioral variables: Observable behaviors or actions. ○​ Their interaction is studied in biopsychology to understand brain-behavior relationships. 4.​ Glial Cells ○​ Supportive cells in the nervous system. Types include: ​ Astrocytes: Support blood-brain barrier, regulate blood flow. ​ Microglia: Act as immune cells in the CNS. ​ Oligodendrocytes (CNS) and Schwann cells (PNS): Myelinate axons. ○​ Implications in diseases like multiple sclerosis (damage to myelin). 5.​ Central and Peripheral Nervous System ○​ CNS: Brain and spinal cord. ○​ PNS: Somatic (voluntary movement) and autonomic systems (involuntary functions). 6.​ Nerves ○​ Bundles of axons in the PNS. Types: ​ Cranial nerves: Connect directly to the brain. ​ Spinal nerves: Connect to the spinal cord. 7.​ Autonomic Nervous System ○​ Regulates involuntary processes. Subdivided into: ​ Sympathetic: Fight or flight. ​ Parasympathetic: Rest and digest. 8.​ Neuroanatomy Terms ○​ Rostral/caudal: Front/back. ○​ Dorsal/ventral: Top/bottom. ○​ Medial/lateral: Middle/side. Chapter 2: Neurons and Electrical Signaling  1.​ Neuronal Cell Membrane ○​ Phospholipid bilayer containing embedded proteins (ion channels and pumps). Maintains separation of ions. 2.​ Ion Channels and Ion Pumps ○​ Channels: Allow passive ion flow (e.g., K+, Na+). ○​ Pumps: Actively transport ions (e.g., sodium-potassium pump: 3 Na+ out, 2 K+ in). 3.​ Resting Potential ○​ Neuron's baseline electrical charge (~ -70 mV). Maintained by selective permeability of K+ and active ion pumping. 4.​ Two Forces Acting on Ions ○​ Diffusion: Ions move from high to low concentration. ○​ Electrostatic pressure: Opposite charges attract, like charges repel. 5.​ Equilibrium Potential for an Ion ○​ The electrical potential at which no net ion flow occurs (balance between forces). 6.​ Sodium and Potassium Equilibrium Potentials ○​ Na+ equilibrium potential: Positive (wants to enter the cell). ○​ K+ equilibrium potential: Negative (wants to leave the cell). 7.​ Voltage-Gated Channels``1`1`1`1`` ○​ Open/close in response to changes in membrane potential, crucial for action potential generation. 8.​ Action Potentials ○​ All-or-none electrical signals propagated along axons. ○​ Depolarization: Na+ influx. ○​ Repolarization: K+ efflux. 9.​ Action Potential Propagation ○​ Wave of depolarization traveling down the axon. Faster in myelinated axons. 10.​Myelination of Axons ○​ Provided by oligodendrocytes (CNS) or Schwann cells (PNS). Gaps between myelin are Nodes of Ranvier, where action potentials regenerate. Chapter 3: Chemical Synaptic Transmission of 1.​ Chemical Synaptic Transmission ○​ Process by which neurotransmitters are released from the presynaptic neuron, cross the synaptic cleft, and bind to postsynaptic receptors. 2.​ Loewi Frog Experiment ○​ Demonstrated chemical signaling using acetylcholine. Stimulating one frog's vagus nerve slowed its heart rate, and transferring its fluid to another frog slowed its heart rate too. 3.​ Neurotransmitters ○​ Chemical messengers. Examples: dopamine, serotonin, acetylcholine, GABA.  4.​ Receptors ○​ Specialized proteins on the postsynaptic cell that bind neurotransmitters. ○​ Ionotropic receptors: Fast, direct ion channel opening. ○​ Metabotropic receptors: Slower, involve second messengers. 5.​ Agonists and Antagonists ○​ Agonists: Enhance neurotransmitter activity. ○​ Antagonists: Block neurotransmitter activity. 6.​ Drug Categories and Mechanisms ○​ Stimulants (e.g., cocaine), depressants, hallucinogens, opioids. ○​ Work by altering synaptic transmission (e.g., blocking reuptake, enhancing release). 7.​ SSRI Drugs ○​ Selective serotonin reuptake inhibitors (e.g., fluoxetine) increase serotonin in the synapse by blocking its reuptake. 8.​ Dopamine and Reward ○​ Dopamine pathways are central to the brain's reward system. Implicated in addiction and reinforcement. Chapter 1: Foundations of Neuroscience Historical Perspectives 1.​ Aristotle: Believed the heart, not the brain, was the source of sensation and thought. 2.​ Ancient Egyptians: Extracted the brain during mummification, viewing the heart as central to the mind. 3.​ Hippocrates: Recognized the brain as the seat of intelligence and emotions. ○​ Quote: "From the brain arise our pleasures, sorrows, and emotions." 4.​ Galen: Proposed "animal spirits" traveled through nerves to convey information. Scientific Evolution ​ Localization vs. Distributed Function: ○​ Broca: Language production linked to the left frontal lobe. ○​ Wernicke: Language comprehension linked to posterior left hemisphere. ○​ Hughlings Jackson: Identified topographic mapping in motor areas. ​ Neuron Doctrine: Santiago Ramón y Cajal, using Golgi staining, demonstrated neurons as discrete units. Methods in Behavioral Neuroscience  ​ Studying the relationships between somatic variables (e.g., brain activity) and behavioral variables (e.g., emotions). Chapter 2: Neurons and Electrical Signaling The Neuron 1.​ Basic Facts: ○​ Brain contains ~100 billion neurons and ~100 trillion synapses. ○​ Neurons communicate via changes in electrical polarization. 2.​ Neuron Types: ○​ Motor neurons: Control muscles. ○​ Sensory neurons: Respond to stimuli. ○​ Interneurons: Integrate and relay signals. 3.​ Glial Cells: ○​ Astrocytes: Regulate blood flow to active neurons. ○​ Microglia: Clean debris after injury. ○​ Oligodendrocytes/Schwann cells: Myelinate axons (CNS/PNS). ○​ Disease: Multiple sclerosis involves demyelination, leading to movement and coordination problems. Neural Electrical Activity 1.​ Resting Potential: ~ -70 mV, maintained by ion pumps and selective permeability. 2.​ Action Potential: All-or-none depolarization triggered by voltage-gated sodium and potassium channels. 3.​ Propagation: ○​ Faster in myelinated axons due to saltatory conduction at Nodes of Ranvier. Chapter 3: Chemical Synaptic Transmission 1.​ Synaptic Transmission: ○​ Neurotransmitters released at synapses bind to receptors on the postsynaptic membrane. 2.​ Loewi's Frog Experiment: Proved chemical transmission by slowing heart rate through transferred fluid containing acetylcholine. 3.​ Neurotransmitters: ○​ Examples: Dopamine, serotonin, acetylcholine, GABA. ○​ Dopamine pathways are linked to reward and addiction. 4.​ Receptors: ○​ Ionotropic: Fast, direct ion channel effects.  ○​ Metabotropic: Slower, second-messenger-mediated. 5.​ Drugs: ○​ Agonists: Enhance neurotransmitter activity. ○​ Antagonists: Block neurotransmitter activity. ○​ SSRIs: Prevent serotonin reuptake to treat depression. Additional Concepts from Slides Neuroanatomy Terms ​ Directional Terms: ○​ Dorsal (top), ventral (bottom), rostral (front), caudal (rear). ​ Cortical Organization: ○​ Gyrus: Raised ridge. ○​ Sulcus: Valley. ○​ Central sulcus separates motor (precentral gyrus) and sensory (postcentral gyrus) regions. Brain Structures 1.​ Forebrain: ○​ Telencephalon: Cerebral cortex, basal ganglia, limbic system. ○​ Diencephalon: Thalamus (sensory relay) and hypothalamus (homeostasis). 2.​ Midbrain: Sensory and motor areas. 3.​ Hindbrain: Includes the pons (motor/sensory relay) and medulla (life support functions). 4.​ Cerebellum: Fine motor control; damage causes coordination loss. Nervous System Divisions ​ CNS: Brain and spinal cord. ​ PNS: Nerves connecting CNS to the body. ○​ Autonomic Nervous System: ​ Sympathetic: Fight-or-flight response. ​ Parasympathetic: Rest-and-digest functions. Imaging and Methods ​ Histology: Golgi stain (neurons), Nissl stain (cell bodies). ​ Imaging: fMRI (blood flow), EEG (electrical activity).