Biological Psychology: Foundations

Module 1: Foundations of Biological Psychology

• Behavioral neuroscience, or biological psychology, combines experimental psychology with physiology.
• It integrates experimental biology, chemistry, animal behavior, psychology, and computer science to study the biological basis of behavior.
• The goal of biological psychology is to elucidate the relationship between the brain and behavior.
• Generalization provides broad explanations from smaller observations, while reduction explains complex phenomena through smaller components.
• Research in behavioral neuroscience uses both generalization and reduction, driven by psychological generalizations and physiological mechanisms.
• The mind-body problem explores the relationship between the mind and the physical body, with dualism suggesting separation and monism proposing unity.
• Dualism posits the mind and body as separate entities, while monism suggests the mind is a product of the nervous system's activity.
• Biological psychology favors a monistic approach.
• The rubber-hand illusion illustrates how visual and tactile information is processed, leading the brain to misattribute touch to an external object.
• It demonstrates the complex interplay between the body and mind.
• Functionalism explains biological phenomena by understanding their useful functions for the organism.
• Natural selection favors inherited traits that increase an organism's likelihood to survive and reproduce, making these traits more common in a population.
• Human brains are relatively larger than other species because of pressures from social interactions, tool use, and environmental problem-solving.
• Larger brains, especially the neocortex, are needed for complex cognitive processing.
• Animal research is guided by the Australian Code for the Care and Use of Animals for Scientific Purposes, and the Queensland Animal Care Protection Act at Griffith University.
• Key guidelines for animal research include respect, justification of use, minimizing harm, high care standards, ethical review, training, and transparency.
• The 3 R's (replacement, reduction, refinement) are used in animal research to avoid animal use, minimize animal numbers, and minimize harm.
• Neuroethics examines the ethical implications of neuroscience research and promotes best practices.
• Informed consent requires researchers to fully inform participants about the study's nature, data handling, and potential benefits and costs.

Module 2: Neural Components and Function

• The nervous system (NS) is composed of neurons and glia, divided into the central (CNS) and peripheral (PNS) nervous systems.
• The CNS includes the brain and spinal cord, which serve as the body's control center.
• The PNS includes all nerves and sensory organs outside the brain and spinal cord.
• Cranial nerves connect to the brain, while spinal nerves connect to the spine.
• The PNS contains three neuron types: sensory, interneurons, and motor neurons.
• Sensory neurons detect environmental changes and send information to the CNS.
• Interneurons in the CNS process and transmit information between sensory and motor neurons.
• Motor neurons control muscle and gland contractions to produce motor behavior.
• Neurons consist of a cell body (soma), a membrane, a cytoskeleton, cytoplasm, and an axon.
• The soma contains internal layers.
• The membrane is made of proteins for substance detection or transport.
• The cytoskeleton is made of protein strands.
• The cytoplasm is the space inside the membrane, containing organelles.
• The axon transmits electrochemical messages from the soma to the terminal buttons.
• Myelin sheath insulates the axon to prevent interference between neuron messages.
• Nodes of Ranvier are gaps in the myelin sheath that facilitate saltatory conduction.
• Terminal buttons send chemical messages to other neurons, and dendrites receive these messages.
• Glial cells are non-neuronal cells that support and maintain neurons, ensuring the NS's structure and integrity.
• They regulate chemical and nutrient supply, provide protection, and remove dead neurons.
• CNS glial cells include astrocytes, microglia, and oligodendrocytes.
• Astrocytes supply nutrients and regulate chemicals.
• Microglia aid in damage control and immune function.
• Oligodendrocytes produce myelin for axon insulation.
• PNS glial cells include Schwann cells, which produce myelin for the PNS, differing from oligodendrocytes.
• The blood-brain barrier (BBB) is formed by tightly packed cells, protecting the brain by blocking harmful substances while allowing essential nutrients to pass.
• It maintains a stable chemical environment, regulates neurotransmitter levels, and protects against inflammation to ensure optimal brain health.
• The withdrawal reflex is an involuntary response to painful stimuli that protects the body.
• Sensory neurons signal the spinal cord upon stimulation where excitatory neurons stimulate motor neurons to contract muscles for withdrawal.
• Simultaneously, inhibitory neurons prevent opposing muscles from contracting, leading to a quick withdrawal.
• A membrane potential is the electrical potential difference inside versus outside a neuron.
• Resting potential is -70mV.
• Hyperpolarization (negative) reduces action potential likelihood.
• Depolarization (positive) increases action potential likelihood.
• The threshold of excitation triggers an action potential when sufficient depolarization occurs.
• At the terminal buttons, the action potential causes neurotransmitter release into the synapses.
• Ions are either positively or negatively charged and located inside or outside a neuron.
• Ion concentration determines an ion's resting charge.
  • Diffusion moves ions from high to low concentration areas.
• Potassium ions (K+) are concentrated inside, whereas sodium ions (Na+) are concentrated outside.
• Electrostatic pressure attracts oppositely charged ions (e.g., Na+ to the inside, K+ to the outside).
• The sodium-potassium pump maintains resting potential by transporting three sodium ions out and two potassium ions into the cell, against their gradients.
• This active transport creates and maintains concentration differences and contributes to a -70 mV internal charge.
• Voltage-gated ion channels (VGIC) are specialized proteins in the neuron's membrane that respond to changes in the membrane potential.
• During an action potential, sodium channels open, allowing Na+ to rush in and depolarize the membrane, and then potassium channels open, allowing K+ to exit, thus repolarizing the membrane.
• Action potentials travel down myelinated axons via saltatory conduction, jumping from node of Ranvier to node of Ranvier, increasing transmission speed.
• In unmyelinated axons, action potentials move along the axon in a continuous wave as voltage-gated ion channels sequentially open and close.
• Synapses form between presynaptic cell terminal buttons and the postsynaptic cell dendritic membrane, or the somatic membrane, or the terminal button of a postsynaptic cell.

Module 3: Nervous System Structure and Organization

• The nervous system divides into the CNS and PNS.
• The CNS includes the brain and spinal cord, and is responsible for sensory processing, higher functions (thought, memory), and motor control.
• The brain which is located in the cranial cavity has the cerebrum that involves sensory perception and voluntary movement.
• The Cerebellum coordinates balance and motor control.
• The diencephalon includes the thalamus and hypothalamus.
  • Responsible for sensory relay and autonomic regulation.
• The brainstem includes the midbrain, pons, and medulla oblongata.
  • Responsible for vital functions, heartbeat, breathing, and blood pressure.
• The spinal cord is located in the vertebral canal.
  • Connects the brain to the body; transmits motor and sensory signals and controls reflex actions.
• The PNS includes cranial nerves managing roles like vision and face movement.
• It also contains spinal nerves used as pathways for communication between the CNS and the body.
• The PNS is divided into the somatic nervous system for voluntary movements and sensory input, and the autonomic nervous system (ANS) for involuntary functions like heart rate and digestion.
• The ANS has two divisions: the sympathetic division preparing for "fight or flight", and the parasympathetic division promoting "rest and digest".
• At the cellular level, the nervous system comprises neurons and glial cells.
• Sensory (afferent) neurons transmit sensory information from the body to the CNS.
• Motor (efferent) neurons carry motor commands from the CNS to muscles and glands.
• Interneurons within the CNS process/relay information between sensory and motor neurons.
• Glial cells (astrocytes, oligodendrocytes, microglia, Schwann cells) provide structural support, nourishment, and protection.
• This coordination allows the nervous system to regulate functions, facilitate movement, and respond to the environment.
• Meninges are layers of connective tissue that cover the nervous system for protection and structure.
• In the CNS, these have the dura mater (outer), arachnoid membrane (middle), and pia mater (inner).
  • The arachnoid membrane contains subarachnoid space with cerebrospinal fluid.
    • Used as a shock absorber and material exchanger.
• The PNS has only the dura mater and pia mater layers.
• The forebrain is the largest/most complex, located at the front, and is critical for higher cognitive functions, sensory processing, and emotional regulation.
• Divisions include the telencephalon and the diencephalon.
• The telencephalon contains the cerebrum divided into two hemispheres.
• Responsible for thought, voluntary movement, reasoning, and perception.
• The cerebrum is divided into lobes.
  • The frontal lobe involves decision-making, problem-solving, and motor control.
  • The Parietal lobe processes sensory information related to touch, temperature, and spatial orientation.
  • The temporal lobe processes auditory information, memory, and language.
  • The Occipital lobe involves visual processing.
• Within the cerebrum, regions are responsible for sensory and motor functions.
  • The sensory cortex in the parietal lobe processes sensory input (touch, pain, temperature).
    • The sensory cortex maps these sensations to body areas.
  • The visual cortex in the occipital lobe interprets visual information from the eyes.
  • The auditory cortex located in the temporal lobe processes sound for hearing.
  • The motor cortex located in the frontal lobe controls voluntary movements by signaling muscles.
• Beneath the telencephalon lies the diencephalon, containing the thalamus for sensory relay (not smell) to the cerebral cortex.
  • It regulates consciousness, sleep, and alertness.
• The hypothalamus maintains homeostasis by regulating bodily functions.
  • Temperature, hunger, thirst, and circadian rhythms.
    • It controls the autonomic nervous system.
    • Links the nervous system to the endocrine system.
  • The Pituitary gland is in two parts.
• The anterior pituitary secretes hormones (growth hormone) to regulate growth, metabolism, and reproduction and the posterior pituitary stores and releases hormones like oxytocin.
  • vasopressin for childbirth, lactation, and water balance.
• Together, the telencephalon and diencephalon enables sensory processing, emotional regulation, motor control, and maintaining homeostasis, making the forebrain central to coordination of bodily functions and higher cognitive abilities.
• The midbrain is a small/vital region between the forebrain and hindbrain.
  • Is useful for sensory processing, motor control, and maintains alertness.
• The midbrain contains the tectum and the tegmentum.
• The tectum is at the dorsal (top) of the midbrain and primarily processes visual and auditory information.
• The colliculi is helpful for integration of visual stimuli.
• The inferior colliculi plays a role in auditory processing.
• Structures are essential for reflexive responses to visual and auditory cues.
• The tegmentum is involved in functions like motor control and consciousness regulation.
• Includes the red nucleus for motor coordination, especially limb movements, and substantia nigra for movement control by dopamine neurons.
• Degeneration of the substantia nigra is linked to Parkinson's disease, which is a motor impairment.
• The reticular formation runs through the tegmentum.
• Plays a role in arousal, attention, and the sleep-wake cycle.
• The Midbrain is crucial for sensory processing, motor control, and consciousness by relaying information and contributing to environmental responses.
• The hindbrain is a part of the brainstem at the posterior region.
• Regulates functions like motor control, coordination, autonomic regulation and maintainong balance.
• The metencephalon and the myelencephalon are the two regions.
• The metencephalon includes the cerebellum and the pons.
  • The cerebellum helps coordinates and fine-tunes voluntary movements.
  • Sensory input is sent from the body, as well as motor commands to adjust movements. - Helpful for motor learning and maintaining posture.
  • The vermis helps in coordinating movements and maintaining body balance.
  • The Pons serves as a communicatioin bridge between parts of the brain.
• Relays signals and helps regulate breathing. - Houses nuclei involved in sensations.
• The myelencephalon contains the medulla oblongata which regulates autonomic functions. - Is essential for survival.
  • Contains the cardiac center that regulates the heart.
  • Contains the vasomotor center that controls blood vessel diameter. -The respiratory centers regulates breathing patterns.
  • Contains the pyramidal decussation for motor fiber crossover, explaining contralateral motor control.
• Hindbrain regulates basic life functions, coordinates movements, and maintains balance.
  • Ensures smooth motor activities.
  • Controls autonomic functions.
• The spinal cord is a cylindrical structure extending from the brain's base through the vertebral column, connecting the rain and body to transmit motor commands and regulate reflexes.
• The spinal cord is divided into segments that correspond to body regions, giving rise to spinal nerves named for their location (cervical, thoracic etc).
• Structurally, the spinal cord has grey matter (neuron cell bodies for information-processing) and white matter (myelinated tracts), divided into dorsal and ventral horns.
• Dorsal horns receive sensory input, and ventral horns contain motor neurons.
• The white matter contains ascending and descending tracts, including the spinothalamic tract for pain/temperature and the corticospinal tract for voluntary motor control.
• The spinal cord mediates rapid reflexes, automatically responding to stimuli without direct brain involvement, such as the patellar reflex.
• The spinal cord is a conduit.
  • Connects to the brain by enabling voluntary movement, by processing sensory input, and by mediating the body's responses.
• Cranial and spinal nerves are responsible for sensory, motor and mixed signals.
  • Cranial nerves have 12 pairs. - Emerges directly from the brain and serves function like sensory input and regulation.
    • Responsible for the sensation of smell and visual information.
      • The vagus nerve plays a role in parasympathetic control.
• Spinal nerves include 31 pairs that emerges from the spinal cord for transmitting signals. - Sensory fibers gets information from receptors. - Forms plexuses and provides the touch and feeling responses.
• Together, the cranial and spinal nerves plays role in sensory perception and motor function while ensuring the ability for one to respond to the environment.
• The autonomic nervous system (ANS) regulates bodily functions (involuntary) and has two divisions( sympathetic and parasympathetic). - The sympathetic division is "fight or flight" - Nerves arises from the thoracolumbar region.
• When activated, the Sympathetic gives adrenaline and increased heart rate. - The "rest and digest" system is promoted in the parasympathetic division.
  • Nerves comes from cranial nerves (III, VII, IX, and X) and the sacral region.
    • When active, there is balance and support.

Module 4: Neurotransmitters and Pharmacology

• Drugs are defined as any exogenous chemical for altering normal cellular operation.
  • Effects of these are measurable changes when individual consumes it.
• Pharmacokinetics involves the drug life cycles.
  • Absorption allows molecules to be absorbed into the body.
  • Distribution allows even spread throughout the body. BBB will have an affect on the body.
  • Metabolism will change the drugs to an inactive form.
  • Excretion is when kidney removes the drug in the urine.
• Dose response curves displays the relationship between dose and strength.
  • Increase leads to change in effect for narrow therapeutic window.
  • Therapeutic index measures safety.
• Tolerance refers to lessening effects when taking drugs over a period of time.
• Withdrawal is the physical dependence on taking drugs.
• Sensitization is opposite of tolerance.
• Together they drive the opioid epidemic.
• An agonist is a substance that binds to a receptor.
• An antagonist blocks and dampens it( prevents receptors from being activated).
• NT are chemicals altered if enyzmes enhance the responsible NT.
• Drugs increase synapse level/ synthesis of NT and precursor chemicals.
• Nt are stored after AP.
• This is caused disrupted to normal NT.
• AP triggers the causing to break and release NT.
• Presynaptic receptors are on the presynaptic cell that regulates NT release.
• Postsynaptic receptors are now located on the other cells that receive signal.
• Molecules also binds depending on receptor function etc.
• Increase of concentration occurs prolonging effects.
• Amino acid neurotransmitters like glutamate and GABA are made up brain function.
• Neurons becomes damaged after periods of excitation.
• Acetylcholine is made in selective cells with the help of choline.
• It enables communcations.
• Nicotinic receptors and muscarinic receptors is on the CNS
• Monoamines are devirived from amino acids.
• Dopamine bonds that provides messages for both signals.
• Serotonin provides to the synaptic signal.
• Histamine located in the brain controls sleep and wakefulness.
• Peptides are made by amino acids.
  • Transmitted for sstoring. -Transport ia facilitated Peptides are long lasting and are deactivated by enzymatic regulation.
• Endocannabinoids are natural. Lipid is not stored in synaptic vesicles and rather synthesized on demand.
• Receptors are metabotropic that has analgesic effects by stimulating the Pns and is deactivated by enzyme.