NERVE SYSTEM Nerve tissue central astrocytes (protoplasmic and fibrous) oligodendrocytes microglia ependyma peripheral Schwann cells satellite cells Neurons Glial cells CNS Astrocytes - fibrous (grey matter) - protoplasmic (white matter) Oligodendrocytes Microglia Ependyme cells Periphery Schwann cells Sattelite cells (amphicytes) Function in neural network Eferent Sensor Interneurons Sensitive Motor Associative Mediator Dopaminergic Cholinergic Serotonergic Aminergic GABAergic nitriergic, peptidergic, … Morphology Unipolar Bipolar Multipolar Pseudounipolar Axon Golgi type I (long) Golgi type II (short) Neurons Glial cells Capillaries Classification of neurons According to the number of processes  Apolar  Unipolar  Pseudounipolar  Bipolar  Multipolar According to the length of axon  Golgi I /long axon – 1 m/  Golgi II /short axon - µm/  Apolar – hairy cells in inner ear  Unipolar – primary sensory cells /rods, cones/  Bipolar – the 2nd neuron in the retina, ganglion vestibulocochleare  Pseudounipolar –  T-shaped process.  branches of the neurite connecting the ganglion cell with the CNS (central branch) and the periphery (peripheral branch).  function as one actively conducting axon, which transmits information from the periphery to the CNS – dorsal root ganglia, some cranial nerves  Multipolar - the most frequent – CNS, the autonomic ganglia Pyramidal neuron of cerebral cortex (inner pyramidal layer, „motorcortex“) Spinal multipolar neuroal 10-100m Perikaryon - round nucleus,dominant nucleolus - basophilic cytoplasm – rod-like mitochondria, GA, Nissl substance GER - neurofilaments, neurotubules - lipofuscin Dendrites, dendritic spines Axon - odstupový konus - initial segment - axolemma Synapse - presynaptic end (terminal arborization) - synaptic cleft - postsynaptic membrane Motori plate - large cholinergic synapse CNS • Gray matter – cell bodies – nonmyelinated fibers – associated neuroglial cells – very dense capillary network • White matter – only myelinated axons of neurons – neuroglial cells (oligodendrocytes) – blood capillaries (lesser than in gray matter) White matter Corpus medullare telencephali Telencephalon 1. Lamina molecularis 2. Lamina granularis externa 3. Lamina pyramidalis 4. Lamina granularis interna 5. Lamina ganglionaris 6. Lamina multiformis Grey matter 1.5-5mm, 0.2-0.25m2 Surface (cortex cerebri) + regions under the cortex (ncl. caudatus, lentiformis, claustrum, amygdale) Isocortex - 11/12 of surface - 8-9109 neurons - 6 layers - homotypic isocortex - heterotypic isocortex Allocortex 1/12 of surface, rhinencephalon Neurons Pyramidal (motorneurons) Granular (stellate) Fusiform (spindle) Cells of Cajal (horizontal) Cells of Martinotti (vertical) Neuroglial cells Plasmatic astrocytes Microglia Santiago R. Cajal Nobel prize 1906 Brodmann classification of isocortex REGIO AREAE FUNCTION Postcentralis 1,2,3,43,(2s) Soamtosensoric, taste Praecentralis 4,6, (4s) Motor Frontalis 8,9,10,11,44, 45,46,47, (8s) associative Insularis 13,14,15,16 Integrative Temporalis 20,21,22,36,37,38,41,42,52 Hearing Parietalis 5,7,39,40 Associative Occipitalis 17,18,19,(19s) Vision Cingularis 23,24,31,32,33 Spontaneous Retrosplenialis 26,29,30 Spontaneous Hippocampica 27,28,34,35,48,51 Smell, Olfactoria area olfactoria trigonum olfactorium Smell Homotypical isocortex Primary motor cortex Primary visiual cortex I. Lamina molecularis II. Lamina granularis externa III. Lamina pyramidalis IV. Lamina granularis interna V. Lamina ganglionaris VI. Lamina multiformis White matter Motor neurons (motoneurons) Lamina ganglionaris (V) – Betz cells Send axons outside CNS and control muscles (directly or indirectly) Always cholinergic – utilize neurotransmiter acetylcholin Cerebellum • Gray matter /cortex cerebelli/ - ca 1mm - 3 distinct layers – Molecular layer /stratum moleculare/ – Purkinje cell layer /stratum gangliosum/ – Granular layer /stratum granulosum/ • White matter – Efferent fibers – Afferent fibers • Nuclei of cerebellum basket cells and stellate cells granule cells and Golgi typ II cells Purkinje cells 1 2 3 Cerebellum basket cells afferent granular cells Cerebellum – white matter efferent Cerebellum – stratum granulare glomeruli /cerebellar islands/ - synapses between Medulla spinalis Spinal cord (medulla spinalis) Fissura mediana anterior Septum medianum posterior A B C Gray matter columns (horns) - posterior - (lateral) canalis centralis - anterior White matter Funiculi: A – dorsal B – lateral C – ventral ventral root of spinal nerve ventral root of spinal nerve Medulla spinalis (HE) – anterior horn and funiculus pia mater motor neurons myelinated axons nuclei of glial cells Medulla spinalis (impregnation) – ventral horn Medulla spinalis (impregnation) – ventral horn: motor neurons spinal autonomic PNS ganglia and nerves Spinal ganglion (HE) nerve nerve epineurium pseudounipolar neurons bundles of nerve fibers c. t. Ganglial cells Bundles of nerve fibers Spinal ganglion (HE) – pseudounipolar neurons + satelite cells Pseudounipolar neuron Satellite glial cell Autonomic ganglion (HE) multipolar neurons satelite cells Autonomic ganglion (HE) bundles of nerve fibers multipolar neurons Autonomic ganglion (HE) ganglionic cells satelite cells nerve fibers Peripheral nerve epineurium perineurium bundles of nerve fibers blood vessels adipose tissue Peripheral nerve (HE) – cross section Peripheral nerve (myelin) – cross section Peripheral nerve (HE) – cross section blood vessel axons with myelin and Schwann Sheath layer of myelin axon unmyelinated fibers Schwann cells Peripheral nerve (HE) – detail of cross section Peripheral nerve – myelin, longitudinal section axon myelin sheath node of Ranvier Peripheral nerve (HE) longitudinal section Myelinated nerve fiber (axon) This is a view on brain structure as it was developed 100 years ago by Cajal and Golgi How can we see brain structure today? • Not only histological stratification and cell types, but also their connections • „connectomics“ of large segments of nerve tissue • Tracing of neuronal fibers through different parts of brain • Novel techniques of preserving bimolecular composition of nerve tissue while making the brain transparent • Brain-hydrogel structure allows for application of fluorescent dyes, labels, etc. • 75. Cortex cerebri • 76. Cortex cerebri /impregnation/ • 77. Cerebellum /impregnation/ • 78. Cerebellum /Nissl substance/ • 79. Medulla spinalis • 80. Plexus choroideus • 81. Ganglion spinale • 82. Ganglion spinale /impregnation/ • 83. Ganglion autonomic • 84. Peripheral nerve – cross section • 85. Peripheral nerve – cross section /myelin/ • 86. Peripheral nerve – longitudinal section • 87. Peripheral nerve – longitudinal section /myelin/ Microscopic structure of the central and peripheral nervous system