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Week 1 notes

Levels of Behavior and Brain Structure

  • Social Level: Focuses on individuals and their behaviors during social interactions.

  • Organ Level: Encompasses major organs such as the brain, spinal cord, peripheral nerves, and eyes.

  • Neural Systems Level: Involves the eyes as well as the visual regions of the brain, which are pivotal for processing visual information.

  • Brain Region Level: Specifically centers on the visual cortex, the area of the brain responsible for visual processing.

  • Circuit Level: Consists of local neural circuits which facilitate communication between neurons.

  • Molecular Level: Examines synaptic interactions at the level of membrane receptors.

  • Cellular Level: Looks at single neurons as fundamental units in brain function.

    Cerebral Cortex has 6 layers

Historical Perspectives on Brain and Behavior

  • Antiquity Views:

    • Aristotle believed the heart was the seat of mental capacity, relegating the brain to cooling blood.

    • Hippocrates countered this by asserting that the brain is the seat of thought and emotion.

    • Galen documented behavioral changes in gladiators with brain injuries, highlighting an early link between brain function and behavior.

Timeline of Neuroscience Development

  • 4000 BCE: Documented euphoriant effects of poppy in Sumeria.

  • 2700 BCE: Shen Nung founded acupuncture practices.

  • 1700 BCE: The Smith Surgical Papyrus features the first medical writings on the nervous system.

  • 177 AD: Galen conducted lectures on brain function.

  • 1000 AD: Al-Zahrawi detailed surgical treatments for neurological conditions.

  • 1402: St. Mary of Bethlehem Hospital became a treatment center for mentally ill patients.

Evolution of Phrenology

  • Old Phrenology: In the 19th century, phrenology assigned distinct functions to different cortical areas. It was believed that bumps on the skull corresponded to enlarged brain regions related to specific behaviors and personality traits.

  • New Phrenology: Expanded understanding of brain function through regions related to various capabilities such as:

    • Motor functions (e.g., voluntary eye movements, face and hand movements)

    • Visual and spatial attention (e.g., visual cortex activities)

    • Analytic reasoning, mathematical approximations, and object memory.

Neurological Disorders

  • Epilepsy: Often referred to as the sacred disease, characterized by recurrent seizures.

  • Dementia: Especially the Pick's disease, a form of frontal-lobe dementia.

  • Brain Development: The human brain reaches 18 weeks gestation before birth.

  • Genetic Brain Disorders: Notable conditions include Autism and Fragile X syndrome.

Stress and Mental Health

  • Stress: Its significant impact on both physical health and mental well-being, affecting brain function and behavior.

  • Schizophrenia: A complex disorder characterized by alterations in thinking, perception, and behavior.

  • Movement disorders: Types and their implications on mobility and coordination.

Neuropharmacology and Addiction

  • Neuropharmacology: The study of how drugs impact the nervous system, including addiction patterns.

Cognitive Functions and Learning

  • Language: The process involving hearing, seeing, reading, and generating words.

  • Sleep and Dreaming: Their role in memory consolidation and cognitive development.

  • Learning and Memory: Key mechanisms that underpin educational practices and cognitive growth.

Neuroanatomy Overview

  • Human Anatomy: Focus on specific brain and spinal cord structures, as well as peripheral nerves.

  • Brain Structures: Understanding different parts of the brain, such as the basal ganglia, limbic system, and cerebellum, and their functions.

Neuron Doctrine

  • Brain is made of independent cells (neurons)

  • Signals are transmitted though synapses

3 types of neurons

Unipolar neurons: They have one single extension that branches out both ways. (Forms receptive pole and output zone.)

Bipolar neurons: Have one axon, one dendrite (sensory)

Multipolar neurons: One axon, many dendrites

Kinds of neurons and function

  • Sensory neurons/Bipolar neurons: respond to environment (light, odor, touch)

  • Motoneurons: Contact muscles or glands

  • Interneurons/multipolar neurons: Receive input from and send it to other neurons (MOST NEURONS)

Glial Cells and Support Functions

  • Types of Glial Cells:

    • Astrocytes: Provide structural support, regulate blood flow and the blood-brain barrier.

    • Oligodendrocytes: Insulate axons with myelin sheaths, crucial for rapid signal transmission in the CNS. (Nodes of Ranvier)

      Multiple Sclerosis: Oligodendrocyte injury from autoimmune attack (Disrupts communication between cells as myelin sheath help for faster action potentials.)

    • Microglia: Act as immune cells in the brain, cleaning up debris.

    • Ependymal Cells: Line the central nervous system's ventricles and are involved in cerebrospinal fluid production.

Synapses and Information Flow

  • Synaptic Transmission: Neurons communicate through synapses where neurotransmitters are released.

  • Functional Zones of Neurons: Each neuron has input, integration, conduction, and output zones facilitating efficient information processing.

Autonomic Nervous System

  • Sympathetic: Prepares body for action (middle spinal segments)

  • Parasympathetic: Rests and digests (Brain stem and very top and bottom spinal cord)

Meninges

  • Dura matter (Top layer)

  • Subdural space (Gap between the subdural space and arachnoid membrane)

  • Arachnoid membrane (Middle Layer)

  • Subarachnoid Space (Space between arachnoid membrane and Pia mater)

  • Pia mater (Bottom layer)

    CEREBRAL VENTRICAL

  • Make cerebrospinal fluid which surrounds and cushions brain

Anatomical Planes and Directions

  • Planes of section: Coronal (front vs. back), sagittal (left vs. right), and horizontal (top vs. bottom) slices of the brain.

  • Directional Terms: Understanding medial, lateral, anterior, posterior, and other terms for describing positions and relationships in the brain.

White Matter vs. Gray Matter

  • White Matter: Composed of myelinated axons that carry signals across brain areas.

  • Gray Matter: Contains neuron cell bodies, processing and integrating information.

Neuroimaging Techniques

  • CT, MRI, PET, fMRI: Different imaging modalities useful for studying brain structure and function, each with unique advantages.

  • CT: X RAY

  • MRI: Magnets

  • PET: Radioactive Chemicals

  • fMRI: Brain activity

  • Functional Aspects: fMRI shows brain activity patterns based on blood flow and oxygen use, particularly useful in understanding functional connectivity during tasks.

Key Insights and Learning Strategies

  • Learning is enhanced through repetition, emotional engagement, and adequate rest. Study strategies include using mnemonics and visualization for better retention of information. Understanding individual brain function can further tailor learning processes.