Physiological Psychology and Psychopharmacology Lecture: Part Two

• Introduction:

  • This is part two of the physiological psychology and psychopharmacology lecture, expanded to three parts.

  • In this part, we cover subcortical and cortical structures of the forebrain and neuroimaging techniques.

  • Part three will cover neurological disorders and psychoactive drugs.

• Subcortical Structures of the Forebrain:

  • Hypothalamus:

  • Maintains homeostasis (temperature, blood pressure, appetite, thirst).

  • Regulates sex characteristics and reproduction via the pituitary gland.

  • Manages stress response through ACTH release.

  • Contains suprachiasmatic nucleus (biological clock):

    • Controls circadian rhythms (sleep-wake cycle, hormone release).

    • Regulates melatonin secretion from the pineal gland based on light sensitivity.

  • Mammillary bodies: Attached to the hypothalamus, critical for memory — damage leads to issues in forming new declarative memories.

  • Thalamus:

  • Acts as a relay station for sensory information (except olfaction) to the cortex.

  • Coordinates sensory and motor functions.

  • Damage can result in conditions like Korsakoff syndrome (often due to thiamine deficiency), affecting memory and causing anterograde/retrograde amnesia and confabulation.

  • Basal Ganglia:

  • Includes caudate nucleus, putamen, and globus pallidus — collectively referred to as the striatum.

  • Important for initiation and coordination of voluntary movement and emotion processing.

  • Damage associated with Huntington's, Parkinson's, and OCD, among others.

  • Limbic System:

  • Includes amygdala (emotion processing, fear, and anger) and hippocampus (memory and learning).

  • Amygdala:

    • Connects emotions to memories; damage leads to Kluver-Bucy syndrome.

    • Linked to PTSD, anxiety, and depression.

  • Hippocampus:

    • Consolidates declarative memories from short to long term.

    • Damage impairs new memory storage but not previously formed memories.

    • Larger in London taxi drivers, linked to spatial memory; degeneration relates to Alzheimer's disease.

• Cerebral Cortex:

  • Divided into left and right hemispheres, each has frontal, parietal, temporal, and occipital lobes.

  • Corpus Callosum: Connects the hemispheres.

  • Frontal Lobe:

  • Contains prefrontal cortex, primary motor cortex, and Broca's area.

  • Prefrontal cortex:

    • Responsible for executive functions (planning, decision-making).

    • Damage impacts judgment, attention, and emotional regulation (dysfunction varies by area of damage).

  • Primary Motor Cortex:

    • Executes voluntary movements; damage may lead to weakness or paralysis on the opposite side of the body.

  • Broca's Area:

    • Language processing; damage causes Broca's aphasia (slow speech, intact comprehension).

  • Parietal Lobe:

  • Contains somatosensory cortex (touch, pain processing).

  • Damage leads to agnosias, contralateral neglect (inattention to one side), and Gerstmann syndrome (finger agnosia, agraphia).

  • Temporal Lobe:

  • Contains auditory cortex and Wernicke's area.

  • Auditory Cortex: Damage leads to auditory agnosia or hallucinations.

  • Wernicke's Area:

    • Damage results in Wernicke's aphasia (impaired comprehension and fluent but incoherent speech).

  • Occipital Lobe:

  • Contains visual cortex; damage can lead to visual agnosia and other visual impairments (e.g., prosopagnosia).

• Neuroimaging Techniques:

  • Two main types: structural and functional imaging.

  • Structural Neuroimaging:

  • Identifies changes (e.g., strokes, tumors).

  • CT (Computed Tomography): Uses X-rays for brain images; quick and cost-effective.

  • MRI (Magnetic Resonance Imaging): Uses magnetic fields for detailed images without radiation.

  • Functional Neuroimaging:

  • Provides insights into brain activity via blood flow, oxygen, or glucose usage.

  • PET (Positron Emission Tomography): Tracks radioactive tracers in active cells.

  • SPECT: Simpler and cheaper than PET but less detailed.

  • fMRI: Observes blood oxygenation changes (similar to MRI).

• Conclusion:

  • The understanding of the brain's structure and function is crucial for diagnosing and treating neurological disorders.

  • Familiarity with neuroimaging techniques enhances our ability to assess brain health.

  • Engaging with examples and questions aids exam readiness, particularly for identifying brain functions and disorders.

Introduction:
This is part two of the physiological psychology and psychopharmacology lecture, expanded to three parts.
In this part, we cover subcortical and cortical structures of the forebrain and neuroimaging techniques.
Part three will cover neurological disorders and psychoactive drugs.

Subcortical Structures of the Forebrain:
Hypothalamus:

• Maintains homeostasis (temperature, blood pressure, appetite, thirst), which is crucial for survival.

• Regulates sex characteristics and reproduction via the pituitary gland, coordinating hormonal release for sexual development.

• Manages stress response through ACTH release, triggering the adrenal glands to produce cortisol during stressful situations.

• Contains the suprachiasmatic nucleus (biological clock):

  • Controls circadian rhythms (sleep-wake cycle, hormone release) which adapt bodily functions to the day-night cycle.

  • Regulates melatonin secretion from the pineal gland based on light sensitivity, influencing sleep patterns.

• Mammillary bodies: Attached to the hypothalamus, critical for memory—damage leads to issues in forming new declarative memories, affecting recall of facts and events.

Thalamus:

• Acts as a relay station for sensory information (except olfaction) to the cortex, ensuring efficient communication between sensory organs and the brain.

• Coordinates sensory and motor functions, playing a role in attention and perception.

• Damage can result in conditions like Korsakoff syndrome (often due to thiamine deficiency), affecting memory and causing anterograde/retrograde amnesia and confabulation (false memories).

Basal Ganglia:

• Includes caudate nucleus, putamen, and globus pallidus—collectively referred to as the striatum, involved in movement regulation.

• Important for initiation and coordination of voluntary movement and emotion processing, playing a role in habit learning and motor control.

• Damage associated with Huntington's, Parkinson's, and OCD, among others, leading to characteristic motor deficits and psychological symptoms.

Limbic System:

• Includes amygdala (emotion processing, fear, and anger) and hippocampus (memory and learning).

• Amygdala:

  • Connects emotions to memories; damage leads to Kluver-Bucy syndrome, resulting in behavioral changes and emotional disregulation.

  • Linked to PTSD, anxiety, and depression, influencing emotional responses and stress regulation.

• Hippocampus:

  • Consolidates declarative memories from short to long term, critical for learning new information.

  • Damage impairs new memory storage but not previously formed memories, highlighting its role in memory formation.

  • Larger in London taxi drivers, linked to spatial memory, showcasing neuroplasticity; degeneration relates to Alzheimer's disease.

Cerebral Cortex:

• Divided into left and right hemispheres, each has frontal, parietal, temporal, and occipital lobes, specializing in different functions.

• Corpus Callosum: Connects the hemispheres, facilitating communication between them.

• Frontal Lobe:

  • Contains prefrontal cortex, primary motor cortex, and Broca's area, integral for higher cognitive functions.

  • Prefrontal cortex:

  • Responsible for executive functions (planning, decision-making), governing behavior and social interactions.

  • Damage impacts judgment, attention, and emotional regulation (dysfunction varies by area of damage).

  • Primary Motor Cortex:

  • Executes voluntary movements; damage may lead to weakness or paralysis on the opposite side of the body due to its contralateral control of movement.

  • Broca's Area:

  • Language processing; damage causes Broca's aphasia (slow speech, intact comprehension), affecting communication skills.

• Parietal Lobe:

  • Contains somatosensory cortex (touch, pain processing), essential for interpreting sensory information.

  • Damage leads to agnosias, contralateral neglect (inattention to one side), and Gerstmann syndrome (finger agnosia, agraphia), disrupting sensory perception and motor coordination.

• Temporal Lobe:

  • Contains auditory cortex and Wernicke's area, critical for auditory processing and language comprehension.

  • Auditory Cortex: Damage leads to auditory agnosia or hallucinations, disrupting sound recognition.

  • Wernicke's Area:

  • Damage results in Wernicke's aphasia (impaired comprehension and fluent but incoherent speech), severely affecting communication abilities.

• Occipital Lobe:

  • Contains visual cortex; damage can lead to visual agnosia and other visual impairments (e.g., prosopagnosia), affecting the ability to recognize objects and faces.

Neuroimaging Techniques:

• Two main types: structural and functional imaging, essential for assessing brain health.

Structural Neuroimaging:

• Identifies changes (e.g., strokes, tumors) that can indicate neurological problems.

• CT (Computed Tomography): Uses X-rays for brain images; quick and cost-effective, commonly employed in emergency settings.

• MRI (Magnetic Resonance Imaging): Uses magnetic fields for detailed images without radiation, providing high-resolution brain images for diagnosis.

Functional Neuroimaging:

• Provides insights into brain activity via blood flow, oxygen, or glucose usage, helping to evaluate brain function.

• PET (Positron Emission Tomography): Tracks radioactive tracers in active cells, allowing assessment of metabolic processes in the brain.

• SPECT: Simpler and cheaper than PET but less detailed, used for a variety of medical conditions.

• fMRI: Observes blood oxygenation changes (similar to MRI), utilized for more precise brain activity monitoring during tasks.

Conclusion:
The understanding of the brain's structure and function is crucial for diagnosing and treating neurological disorders.
Familiarity with neuroimaging techniques enhances our ability to assess brain health.
Engaging with examples and questions aids exam readiness, particularly for identifying brain functions and disorders.