Central Nervous System Histology Slide Orientation 1

Spinal cord Dorsal horns: Interneurons Ventral horns: Motor neurons Lateral horns: Sympathetic neurons Parasympathetic (S2-4) neurons DRG: Sensory (pseudounipolar) neurons Autonomic ganglia: Post ganglionic neurons with unmyelinated axons. Sympathetic: paravertebral ganglia Parasympathetic: In organs

65-2 Lumbar Spinal Cord, H&E Dura mater D.R.G. DRG=dorsal root ganglia Spinal Cord Myelinated nerves

#65-1N Spinal cord and DRG Dorsal horn Lateral horn Ventral horn Dorsal root ganglion (DRG)

Dorsal nucleus of Clarke 66a Thoracic Spinal Cord Dorsal median sulcus Dorsal nucleus of Clarke (proprioceptive) Dorsal horn Lateral horn Ventral horn Ventral median fissure

66a Thoracic Spinal Cord Neurons in Lateral Horn Neurons in ventral Horn

65-1N Motor neurons, glial cells and neuropil Note: the “glial cells” are astrocytes, oligodendrocytes, and/or microglia, which are typically very difficult to distinguish in routine stains of normal tissue. In response to injury, there is marked proliferation of reactive astrocytes, a phenomenon known as “gliosis,” in which case it would be pretty safe to ASSUME the glial cells seen are mostly astrocytes. However, the only way to know FOR SURE would be an immunohistochemical stain. Neuropil

Dorsal root ganglion cells

#74 Sympathetic ganglion cells #75 Parasympathetic ganglion cells Seminal vesicle

Sensory and Autonomic Neurons (DRG) (Parasympathetic)

Brain Cerebrum Cerebellum 3rd ventricle 4th ventricle Pons Sulcus (sulci) Gyrus (gyri) 3rd ventricle Cerebellum 4th ventricle Pons Medulla oblongata

Cerebrum and Cerebellum 77

#77 Cerebellum #76b Cerebrum C: Cortex of gray matter W: White matter C C C W C=cortex W=white matter W W

#77 Cerebellum Cortex White matter

#77 Cerebellum ML GL WM Purkinje neurons (cells) ML=molecular layer WM=white matter GL=granule cell layer WM Purkinje neurons (cells)

#77a Cerebellar Cortex

#76 Cerebrum White matter Cortex of gray matter

#76 Cerebral cortex Ross and Pawlina, p.311

C C Cerebellum Cerebrum W W C: Cortex of gray matter W: White matter Purkinje cells (neurons) C C Pyramidal cells (neurons) W W

Hippocampal Formation Posterior View Lateral View

LIMBIC LOBE (Cortical Areas) Cortex Type Cingulate gyrus & Isthmus Neocortex (six layers) Subcallosal area Parahippocampal Gyrus Paleocortex (3-5 layers) Uncus Hippocampus Archicortex (3 layers) (Deep within parahippocampal gyrus) “Hippocampus:” so-named because of it’s similarity to a sea-horse

Hippocampal Formation Dentate Gyrus Hippocampus Subiculum Martin: Neuroanatomy Figs. 15-3, 4, 14

#NP004N Hippocampal region CA: Cornus ammonis Choroid plexus CA2 Fornix Lateral ventricle CA3 Dentate gyrus Hippocampus CA1 through CA3 are specific regions of cell columns that run the length of the hippocampal formation. Since the hippocampus is curved, the columns are horn-shaped and called Cornu Ammoni (horns of Ammon) Here, the hippocampus is cut in coronal section, so the “columns” would be coming out at you) CA1 Subiculum

3 layers of Dentate gyrus Archicortex (3 layers), as opposed to Neocortex (6 layers) Molecular layer Molecular layer (dendrites of granule cells) Granule cell layer (neurons) Polymorphic layer Polymorphic layer (interneurons)

3 layers of Hippocampus (Archicortex) Polymorphic layer Pyramidal cell layer Molecular layer Pyramidal cells