Dual approach to learning Introduction to Neuroanatomy neuroanatomy: • Structure-function relationships • Functional anatomy – Localization of function in the CNS – Neural structures that serve particular functions; e.g., pain path from skin to • Non-invasive brain imaging cortex for perception – CAT: structure, low resolution • Regional anatomy – MRI: structure, high resolution – Localization of structures in particular brain – PET: function, low resolution regions –fMRI: function, high resolution

Lecture objectives: • Overview of brain structures to “demystify” anatomical content in Neural Science lectures • Survey brain structure-function relations to provide background for first labs Introduction to Neuroanatomy I: Regional Anatomy First half of lecture:

• Quick review of basic CNS organization • Use development to understand principles of structural organization of CNS

Second half: Functional localization

Brief Overview of Mature CNS CNS Organizational Principles Neuroanatomy • Tubular organization of central nervous system • 1) Tubular organization of central • Columnar/longitudinal organization of spinal nervous system and cranial nerve nuclei • 2) Columnar/longitudinal organization of Nuclei: locations of Ganglia: locations of spinal and cranial nerve nuclei neuron cell bodies w/in neuron cell bodies in the central nervous the periphery • 3) Complex C-shaped organization of system

cerebral cortex and deep structures Tracts: locations of Nerves: locations of axons w/in the central axons in the periphery nervous system

1 Brief Overview of Mature CNS Neuroanatomy Dorsal surface • 1) Tubular organization of central nervous system • 2) Columnar/longitudinal organization of spinal and cranial nerve nuclei • 3) Complex C-shaped organization of cerebral cortex Dorsal and nuclei and structures located beneath cortex root – Lateral ventricle – Basal ganglia – Hippocampal formation & Fornix Gray matter Ventral root White matter Spinal nerve

Ventral surface NTA 1-4

Neural Ectoderm Neural Induction plate

•Portion of the dorsal ectoderm becomes Neural committed to become the nervous system: groove Neural tube wall: Neural plate neurons & glia of CNS Neural Neural tube cavity: tube ventricular system

Neural crest: PNS White matter neurons, etc Gray matter NTA 3-1

3-vesicle stage 5-vesicle stage Brain vesicles: Rostral Forebrain Cerebral Forebrain Lateral hemisphere ventricle Midbrain Neural Tube Development Midbrain Diencephalon Hindbrain Midbrain Hindbrain 3rd Pons & ventricle Cerebellum Cerebral Rostral neural tube forms the Medulla aqueduct 4th brain ventricle Spinal cord Caudal neural tube forms Spinal cord Caudal the spinal cord Central canal Cephalic Cephalic flexure flexure

NTA 3-2 NTA 3-2 …by the 5 vesicle stage, all 7 major brain divisions are present

2 The cephalic flexure persists into maturity

Cephalic flexure

NTA 1-13

Dorsal horn Alar plate Sulcus limitans

Central Spinal cord & brain stem have a canal similar developmental plan Basal plate Ventral horn • Segmentation Dorsal horn • Nuclear organization: columnar Central canal

Ventral horn NTA 3-7

Similarities between SC and brain stem development

Dorsal horn •Sulcus limitans separates sensory and motor nuclei •Nuclei have columnar shape

Dorsal Key differences root • 1) central canal enlargement motor medial and sensory lateral Ventral • 2) migration away from ventricle root • 3) >> sensory and motor Ventral horn

3 Medulla development

4th Vent Striated/branchio. Alar plate Striated/somite Autonomic. Vestibular/auditory.

Somatic sensory.

Taste/viscerosensory Sulcus limitans Basal plate Inferior olivary nucleus

Alar plate and migrating Alar plate neuroblasts Basal plate Basal plate

NTA 3-8 NTA 3-9

Pons development Midbrain development

4th Vent Striated/branchio. Alar plate Striated/somite Vestibular/auditory. Cerebral aq. Alar plate Somatic sensory. Somatic sensory. Taste/viscerosensory Autonomic. Autonomic. Basal plate Sulcus limitans Pontine nuclei

Striated/somite Basal plate Red Sulcus limitans Sub. nigra nucleus More like spinal Cord b/c fewer nuclear classes and cerebral aqueduct Alar plate Basal plate Basal plate NTA 3-10 NTA 3-11

Similarities between forebrain and hindbrain/spinal development Diencephalon •Tubular • Thalamus – Gateway to cortex Key differences • Hypothalamus • 1) CH more complex than BS/SC – Control of endocrine and bodily functions • 2) Cortical gyri more complex anatomy than nuclei – Circadian rhythms • 3) Subcortical nuclei are C-shaped – Confusing: structure in two places on image –Etc.

4 Cerebral Cortex Development

Parietal

Frontal Occipital

Temporal

NTA 3-14

Summary • 7 Major components of the central nervous system & Ventricles Forebrain Development & C-shaped • All present from ~ 1st prenatal month Structures • Longitudinal organization of SC and BS nuclei – Columns • Cerebral cortex (NTA 3-15) – Anatomical and functional divisions • Lateral ventricles (NTA 3-16) • Striatum (NTA 3-16) • C-shape organization of cerebral hemisphere structures and diencephalic • Hippocampal formation and fornix – Cerebral cortex (NTA 3-17) – Lateral ventricle – Striatum – Hippocampal formation and fornix

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