Department of Histology and Embryology Medical faculty KU Bratislava

NERVOUS TISSUE

RNDr. Mária Csobonyeiová, PhD ([email protected]) Nerve tissue neurons /main cells/ (perikaryon = cell body=soma,dendrites,axon), 4 -150 µm

glial cells /supporting cells/ - 10 times more abudant CNS- oligodendrocytes, astrocytes, ependymal cells,microglia PNS - Schwann cells, satelite cells Neuron independentNeuron anatomical and functional unit responsible for:  receiving of different types of stimuli  transducing them into the nerve impulses  conducting them to the nerve centers development – embryonal neuroectoderm Morphology of the neurons

Pseudounipolar neuron! (spinal ganglion) Methods used in neurohistology Staining methods:  Luxol blue and cresyl violet (nucleus+nucleolus+Nissl body)  Luxol blue (myelin sheath) and nuclear red (nucleus + nucleolus+Nissl body) Impregnations according -  Holmes – neurons, axon, dendrites - neurofibrils (brown-violet)  Golgi – neurons + astrocytes (black) with golden background  Cajal – astrocytes (black) with red background  Rio del Hortega – microglia (black) with gray-violet background  OsO4 - myelin sheath (black), staining for lipids and lipoproteins (myelin) Microglia (phagocytosis)

Astrocytes (supporting role, Oligodendrocytes nutrition, healing (formation of myelin of defects - glial sheath) scars, formation of BBB)

Ependymal cells (regulation of stable chemical constitution of CSF) CSN Gray matter: White matter: - bodies of neurons, dendrites - myelinated and unmyelinated axons - initial portion of axons - no bodies of neurons! - protoplasmic astrocytes, microglia - oligodendrocytes, microglia - capillaries - capillaries - unmyelinated axons (occationally) Multipolar neurons and ependymal cells - spinal cord (luxol blue and nuclear red)

motoneurons Gray matter

Central canal

White matter Multipolar neurons and ependymal cells, spinal cord (luxol blue and nuclear red)

motoneurons

Nissl substance

nucleus

nucleolus Multipolar neurons and ependymal cells, spinal cord (luxol blue and nuclear red)

motoneurons Multipolar neurons and ependymal cells of central canal in spinal cord (luxol blue and nuclear red)

Central Ependymal cells canal Multipolar neurons and ependymal cells of central canal in spinal cord (luxol blue and nuclear red)

Ependymal cells

Central canal Neurofibrils – spinal cord (Holmes)

- neurotubules - neurofilaments (impreg. neurofibrils) Neurofibrils, spinal cord (Holmes)

gray white matter matter Neurofibrils, spinal cord (Holmes)

Multipolar neurons Neurofibrils, spinal cord (Holmes)

white matter LITTLE BRAIN (cerebellum)  Gray matter→ cortex (3 layers) + cerebellar nuclei  White matter→ medulla

stratum moleculare

stratum gangliosum

stratum granulosum

Purkinje medulla cell Cerebellum (HE)

stratum cortex moleculare

stratum gangliosum

stratum granulosum

medulla cortex

Purkinje neurons, cerebellum(HE) Purkinje neurons, cerebellum (HE)

nucleus

nucleolus Purkinje neurons, cerebellum (HE)

dendrites Purkinje neurons, cerebellum (HE) cortex of the brain

Betz Betzove cells bunky Protoplasmic astrocytes Fibrous astrocytes – in the – in the gray matter; many white matter; few long processes short-branched processes Pyramidal neurons and astrocytes, great brain (Golgi)

pyramidal neurons Pyramidal neurons and astrocytes, great brain (Golgi)

protoplasmic astrocyte Pyramidal neurons and astrocytes, great brain (Golgi)

protoplasmic astrocyte Pyramidal neurons and astrocytes, great brain (Golgi)

dendrites

axon Pyramidal neurons and astrocytes, great brain (Golgi)

protoplasmic astrocyte Pyramidal neurons and astrocytes, great brain (Golgi)

Fibrous astrocyte Microglia /glial cells/  in the gray and the white matter  small elongated cells with short irregular processes dense elongated nuclei  phagocytic cells  represent a mononuclear-phagocytic system in nervous tissue

 are involved with inflammation and repair in CNS Microglial cells, great brain (Rio del Hortega) Microglial cells, great brain (Rio del Hortega) Microglia (Rio del Hortega) Peripheral nervous system Ganglia, peripheral nerves Ganglia Spinal ganglion Autonomic ganglion  on the posterior nerve roots of  constitute the intramural the spinal cord ganglia  cell bodies of the  cell bodies of multipolar pseudounipolar neurons neurons  satellite cells  few satellite cells (irregular cover)  dense connective tissue  connective tissue capsule capsule Pseudounipolar neuron of spinal ganglion Pseudounipolar neurons and satellite cells, spinal ganglion (luxol blue and nuclear red)

Pseudounipolar nerons Pseudounipolar neuron and satellite cells, spinal ganglion (luxol blue and nuclear red)

Satellite cells Pseudounipolar neurons Schwann cells - neurolemmocytes  form a lipid rich layer – myelin sheath around the axons in PNS! (one Schwann cell – one axon)  protection for unmyelinated axons

Unmyelinated nerve fiber Myelinated nerve fiber Myeline sheaths, peripheral nerve, cross section (impregnation by OsO4)

Nerve bundles Myeline sheaths, peripheral nerve, cross section (impregnation by OsO4)

Myelin sheaths of nerve fibers Myeline sheaths, peripheral nerve, longitudinal section (impregnation by OsO4) Thank you!

Ross-Histology-Text-and-Atlas-6th edtition Junqueira's Basic Histology: Text and Atlas, 13th Edition