Introduction to Neuroscience

Intro to Neuroscience Lecture 1 - Sept 5th

What is Psychology? (In this context)

  • Purpose: Expanding understanding of the brain.

Prehistoric Brain Surgery: Trephining

  • Trephining: A form of neurosurgery practiced for around 7000 years.

Ancient Views of the Nervous System

  • Stone Age Conept (Trephining)

    • Evidence of brain surgery in early cultures.

  • Edwin Smith Papyrus (1500 B.C.E)

    • Ancient literature detailing treatment of diseases and behavioural disorders.

    • The brain was described as a significant organ.

The Science of Brain and Behaviour

  • Encompasses the past, present, and future of neuropsychology.

  • Early Egyptians and Greeks, including Aristotle, believed the heart was responsible for mental processes.

  • Hippocrates (circa 400 B.C.) countered, identifying the brain as the seat of thoughts and emotions.

  • Galen (circa AD 129-199):

    • Gained insights from treating brain-injured gladiators.

    • Proposed that behaviour is a product of brain-nerves functioning.

  • Leonardo da Vinci (1452-1519):

    • Innovated anatomical drawings; utilized cross sections in studies.

  • Rene Descartes (1596-1650):

    • Researched animal behaviour through the lens of machinery.

    • Introduced the concept of spinal reflexes and neural pathways.

Brain Utilization Myth

  • 10% Brain Usage Myth:

    • Popular belief associated with William James.

    • Wilder Penfield's discovery of the “silent cortex” demonstrated that large areas of the brain had no observable function when electrically stimulated.

  • Albert Einstein:

    • Alleged intellectual capabilities connected to the silent cortex usage.

Music and Intelligence

  • Raucher et al. (1993):

    • Study found that 10 minutes of Mozart improved spatial reasoning among undergraduate students temporarily (the Mozart Effect).

    • Addressed Georgia's initiative providing classical music to children.

    • Concluded the ‘Mozart Effect’ stems more from enjoyable arousal than music alone.

Science of Brain and Behaviour

  • Quote by Hermann Ebbinghaus (1908):

    • Psychology has a long past but short history, indicating continuous evolution and study in the field.

Historical Neurosurgery Practice

  • Re-revisited concepts of prehistoric trephining and diseases/behavioural treatments present in ancient texts like the Edwin Smith papyrus.

  • Historical thoughts from Egyptians and Greeks indicating brain’s perceived lesser importance compared to the heart, specifically Aristotle's claims.

Mentalism vs. Localization of Function

  • Mentalism: Aristotle (350 B.C.):

    • Suggested heart responsible for feelings (blood and temperature).

  • Hippocrates:

    • Identified the brain's role in emotions.

  • Galen:

    • Distinguished between heart and brain functions, suggesting fluid balance in brain ventricles caused emotional responses.

  • Renaissance Advances:

    • Da Vinci's anatomical studies; Descartes advocating mechanistic views in animal behaviour.

Phrenology (19th Century)

  • Promoted brain region specialization; connection between skull bumps and behavioural traits invoked by physiognomist.

Functional Localization and Language

  • Localization of Function:

    • Confirmed by Broca and Wernicke.

    • Damage to specific brain areas correlated with predictable impairments:

    • Broca’s area:

      • Associated with speech production.

    • Wernicke’s area:

      • Associated with language comprehension.

Neuroanatomy: Under the Microscope

  • Reticular Theory (Golgi):

    • Early neurobiological theory positing interconnected neurons as a single network (now obsolete).

  • Golgi Staining:

    • Developed staining methods to visualize cellular structures facilitating early neurobiology.

Development of Neuroscience

  • Santiago Ramón y Cajal:

    • Drew observations influenced by his medical background, elucidating that neurons are individual cells forming interconnected networks.

  • Discerned organizational elements in complex structures such as the retina and cerebellum.

The Neuron Doctrine**

  • Proposed that the nervous system is made up of individual cells (neurons).

Connecting Behaviour to Neurons

  • Donald Hebb proposal:

    • Psychological phenomena can stem from brain activity.

  • Introduced the concept of Hebbian synapses, which are plastic, allowing changes in response to behaviour.

  • Eric Kandel:

    • Established connections between changes at the neuron level and behavioural changes across studies.

Neuroscience as a Discipline

  • Psychology: The study of behaviour.

  • Biological psychology connects human behaviour with the biological processes in the brain.

  • Neuroscience is influenced by a variety of fields including biology, psychology, and anatomy.

Lecture 2 - Sept 12th

Anatomy in Neuroscience

  • Comparative Anatomy:

    • Relationship of brain mass and neural connections.

Measuring Differences in Brain Function

  • Correlations: Value of knowing one variable to predict another.

  • Residuals: Distance from the best-fit line in predictive models.

  • Human cortical complexity:

    • greater complexity indicated through increased folds, providing enhanced surface area and neuron density.

Evolutionary Context

  • Increase in neuroanatomical complexity mirrored evolutionary history.

  • Gyrification: The process by which increased surface area is achieved without substantial brain volume increase essential for evolutionary advantage.

Brain Size and Intelligence

  • Executive brain ratios as indicators of intelligence focused on comparative structures between brainstem and cerebrum across species.

Anatomical Terminology

  • Anatomical Directions: Local vs. global frames of reference that include anterior, posterior, dorsal, and ventral designations.

Brain Sections and Cellular Differences

  • Brain organized structurally through anatomical nomenclature reflecting the cranial architecture.

  • Broadmann’s Organization: 52 areas distinguished by cytoarchitecture based on cellular layers contributing to form and function.

Major Divisions in Brain Development (Embryology)

  • Telencephalon:

    • Most evolved; regulates cognitive processes such as thought.

  • Brain functions split by lateralization; Left brain focuses on logic while the right engages in spatial, musical, and emotional tasks.

Limbic System and its Functions

  • Framework for motivational behaviours and emotional regulation through structure including the hippocampus and amygdala.

Lecture 3 - Sept 19th

Brain and Behaviour Relationship

  • Examined through observations of lesions (e.g., Phineas Gage) revealing the critical connection between psychological function and specific brain areas.

  • Exploration of Montreal Procedure: Localization of function via stimulation of cortical surfaces during awake surgeries for therapeutic insights.

Modern Techniques: Mapping and Brain Stimulation

  • Transmagnetic Stimulation (TMS): Non-invasive brain stimulation indicating causal mapping.

  • Different techniques (CT, MRI) provide distinct insights into structure vs. function:

Neuroimaging Techniques & Their Applications

  • CT Scan: X-rays to map brain anatomy based on absorption profiles.

  • MRI: Uses magnetic fields to align atoms within tissues; high resolution but not indicative of function.

  • fMRI: Measures shifts in blood oxygenation to assess brain activity dynamics.

Lecture 4 - Oct 3rd

Micro Anatomy and Neural Transmission

  • Neuron Hypothesis:

    • Neurons directly account for behaviour.

  • Neural Structure: Each neuron contains several functional zones for integrating and transmitting information effectively.

  • Neuronal Types: Multipolar, bipolar & unipolar neuron classifications.

Axonal Structure and Functions

  • Detailed structure of neuron components including axons and dendrites essential for effective communication throughout the nervous system.

Key Processes in Neural Communication

  • Membrane Potential:

    • Resting membrane potential determined by ion distribution; sodium-potassium pumps play a vital role.

  • Action Potential Generation: Triggered by voltage-gated channels, typical stages include depolarization and repolarization phases.

Neural Integration and Communication

  • Integration leading to action potentials relies on both excitatory and inhibitory postsynaptic potentials.

Neural Conduction Methods

  • Comparative assessments in conduction speeds across myelinated vs. unmyelinated axons regarding saline conduction properties.

Lecture 5 - Oct 10th

Synaptic Transmission

  • Mechanisms of Neurotransmission: Comprised of chemical synapses where pre-synaptic vesicles release neurotransmitters responding upon action potential arriving.

  • Established classifications of neurotransmitter receptors: Ionotropic and metabotropic, including their respective functional differences.

Chemical Synapses vs. Electrical Synapses

  • Introduced varying efficiencies, benefits of flexibility and specificity in chemical signal transmission compared to speed in electrical synapses.

Lecture 6 - Oct 17th

Sensory Perception Concepts

  • Core sensory perception mechanisms highlighted: transduction, organization, and processing.

  • Unique sensory organ roles differing in specific receptor cells correlating to varied stimuli, including vision.

Mechanism of Sensory Adaptation

  • Adaptive features securing distinction between intense and constant stimuli enhancing overall sensory processing efficacy.

Critical Periods of Development (Lecture 7 - Nov 7th)

  • Identification of periods wherein environmental exposures profoundly influence developmental trajectories.

  • Emphasizing ongoing adaptability throughout human life mirroring brain functional maturation.

Neuronal Development Processes

  • Included stages like neurogenesis, cell migration, differentiation, and synaptic connectivity.

  • Current research explores stem cell replacement theories within the scope of neurological disorders.

Memory Processes and Implications (Lecture 9 - Nov 21st)

  • Distinctions among memory types (declarative vs. non-declarative) relative to specific brain regions.

  • Case studies (e.g., HM case) enhanced understanding of long-term memory formation correlational to medial temporal structures, identifying the essential role of the hippocampus in consolidation.