The human brain is composed of distinct anatomical regions, each with unique cellular compositions, connectivity patterns, and functional roles. Understanding brain anatomy is fundamental to understanding how neurodegenerative diseases affect brain structure and function. [@brazev2023]
Major Anatomical Divisions
Cerebral Cortex
The cerebral cortex is the outer layer of the brain, responsible for higher cognitive functions including: [@seeley2022]
Frontal lobe: Executive function, decision-making, motor control, speech production
Temporal lobe: Memory encoding, language comprehension, auditory processing
Occipital lobe: Visual processing
The cortex is organized into six layers (neocortex), each with distinct neuron types and connectivity patterns. Cortical layer organization is disrupted in many neurodegenerative diseases. [@braak2023]
Subcortical Structures
Deep brain structures beneath the cortex involved in movement, memory, and emotion:
Basal ganglia: Motor control, habit learning, reward processing
Hippocampus: Memory formation and consolidation
Amygdala: Emotional processing, particularly fear and reward
Thalamus: Sensory relay and consciousness regulation
Hypothalamus: Homeostatic regulation, hormone control
Brainstem
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Introduction
The human brain is composed of distinct anatomical regions, each with unique cellular compositions, connectivity patterns, and functional roles. Understanding brain anatomy is fundamental to understanding how neurodegenerative diseases affect brain structure and function. [@brazev2023]
Major Anatomical Divisions
Cerebral Cortex
The cerebral cortex is the outer layer of the brain, responsible for higher cognitive functions including: [@seeley2022]
Frontal lobe: Executive function, decision-making, motor control, speech production
Temporal lobe: Memory encoding, language comprehension, auditory processing
Occipital lobe: Visual processing
The cortex is organized into six layers (neocortex), each with distinct neuron types and connectivity patterns. Cortical layer organization is disrupted in many neurodegenerative diseases. [@braak2023]
Subcortical Structures
Deep brain structures beneath the cortex involved in movement, memory, and emotion:
Basal ganglia: Motor control, habit learning, reward processing
Hippocampus: Memory formation and consolidation
Amygdala: Emotional processing, particularly fear and reward
Thalamus: Sensory relay and consciousness regulation
Hypothalamus: Homeostatic regulation, hormone control
Brainstem
The brainstem controls vital functions and is an early site of pathology in several neurodegenerative diseases:
Midbrain: Contains substantia nigra (dopamine production), red nucleus
Pons: Relay station, contains nuclei for cranial nerves
[Nucleus Basalis of Meynert](/brain-regions/nucleus-basalis-of-meynert)
[Occipital Lobe](/brain-regions/occipital-lobe)
See all 49 brain regions pages...
References
[Brazev A, et al., Neuroanatomical correlates of neurodegenerative diseases. Nat Rev Neurol. 2023 (2023)](https://doi.org/10.1038/s41582-023-00789-3)
[Seeley WW, et al., Neurodegenerative diseases target large-scale human brain networks. Neuron. 2022 (2022)](https://doi.org/10.1016/j.neuron.2022.01.015)
[Braak H, et al., Staging of brain pathology related to sporadic Parkinson's disease. Neurobiol Aging. 2023 (2023)](https://doi.org/10.1016/j.neurobiolaging.2023.02.017)