Brain and Behavior class

Brain and Behavior

Neural Communication

• Similarities in brain regions engaged in information processing.

• Humans and animals have comparable mechanisms for processing information.

Nervous System

Central Nervous System (CNS)

• Brain: Responsible for thinking, calculation, feeling, and controlling motivation.

• Spinal Cord: A bundle of long neural pathways connecting the brain to the body.

Neurons: The Units of the Nervous System

• Components of a Neuron:

  • Dendrites: Receive signals from other neurons.

  • Axon: Transmits impulses away from the cell body.

  • Cell body (soma): Contains the nucleus and maintains the neuron.

  • Axon Terminals: Endpoints of the axon where neurotransmitters are released.

  • Myelin Sheath: Insulates the axon, speeding up neural transmission.

Neural Transmission

• Neurons: Comprised of ions, which are positively or negatively charged particles.

• Action Potential: An electrical impulse that travels along the neuron.

• Resting Potential: The polarized state where negative ions are inside the cell membrane, and positive ions are outside.

• Refractory Period: Time after an action potential during which a neuron is unable to fire.

• Threshold: Minimum level of electrical charge to trigger an action potential.

• All-or-None Principle: Neurons either fire at full strength or not at all.

Synaptic Transmission

• Key Components:

  • Synaptic Vesicles: Contain neurotransmitters.

  • Receptor Sites: Locations on the postsynaptic neuron where neurotransmitters bind.

  • Reuptake: The process of reabsorbing neurotransmitters back into the presynaptic neuron.

  • Enzymatic Deactivation: Breakdown of neurotransmitters by enzymes.

Neurotransmitters and Their Functions

Primary Neurotransmitters

• Acetylcholine: Involved in muscle contractions and memory. Related to Alzheimer's Disease.

• Dopamine: Associated with rewarding sensations, movement, and thought processes. Linked to Parkinson's disease and schizophrenia.

• Serotonin: Influences mood, sleep, and appetite. Implicated in depression.

• Epinephrine: Related to fight or flight responses.

• Norepinephrine: Involved in arousal and alertness. Related to depression and stress response.

• GABA: Major inhibitory neurotransmitter. Calms anxiety and can treat seizures.

• Glutamate: Key in learning and memory; excessive levels can cause migraines.

• Endorphins: Natural painkillers; linked to pleasure and reduced pain perception.

Divisions of the Nervous System

Central Nervous System (CNS)

• Comprises the brain and spinal cord.

• Interneurons facilitate communication within the CNS.

Peripheral Nervous System (PNS)

• Connects the CNS to the rest of the body.

• Includes sensory and motor neurons.

Autonomic Nervous System

• Controls involuntary actions of internal organs and glands.

Divisions:

• Sympathetic Nervous System: Activates fight or flight responses.

• Parasympathetic Nervous System: Calms the body and conserves energy.

Endocrine System

• Comprised of glands that secrete hormones into the bloodstream, affecting long-term bodily functions.

• Key Glands:

  • Pituitary Gland: The master gland; controls other glands and growth hormones.

  • Adrenal Glands: Produce adrenaline for stress response.

Brain Plasticity

Adaptation in the Brain

• Neuroplasticity: The brain's capacity to change its structure and function based on experiences.

  • Functional Plasticity: The brain compensates for damages by reallocating functions.

  • Structural Plasticity: The physical alteration of neural pathways in response to learning or environment.

Structures and Functions of the Brain

Brainstem

• Responsible for basic life functions:

  • Medulla: Controls breathing and reflexes.

  • Pons: Relays information and regulates sleep and breathing.

  • Cerebellum: Coordinates voluntary movements and balance.

Forebrain

• Cerebral Cortex: Outer layer responsible for advanced functions like reasoning, perception, and language.

• Limbic System: Regulates emotions and memory.

  • Hippocampus: Involved in forming memories.

  • Amygdala: Controls emotion and fear responses.

Hemispherical Functionality

Left Hemisphere

• Language processing, logical reasoning, and analytical tasks.

Right Hemisphere

• Visual and spatial processing, art appreciation, and emotional expression.

Corpus Callosum

• Thick band connecting hemispheres; allows communication between them.

Imaging Techniques for Brain Activity

• EEG: Measures electrical activity.

• CT Scan: Uses X-rays for structural imaging.

• MRI: Uses magnetic fields to visualize brain structures.

• PET Scan: Detects radioactive glucose to analyze brain activity.

• fMRI: Monitors blood flow and energy use during specific tasks.