1、Neuron :Supporting cells :CNS : neuroglia (glia)PNS : Schwann cells and satellite cellsFunctions :physical supportelectrical insulationmetabolic exchangeblood-brain barrierComposition of Nervous Tissue神經(jīng)元和神經(jīng)膠質(zhì)細胞膠質(zhì)細胞優(yōu)秀Types and Functions of GliaName of Glial CellFunctionAstrocyte (Astroglia)Star-shap

2、ed cells that provide physical and nutritional support for neurons: 1) clean up braindebris; 2) transport nutrients to neurons; 3) hold neurons in place; 4) digest parts of dead neurons; 5) regulate content of extracellular space MicrogliaLike astrocytes, microglia digest parts of dead neurons.Oligo

3、-dendrogliaProvide the insulation (myelin) to neurons in the central nervous system.Satellite CellsPhysical support to neurons in the peripheral nervous system.Schwann CellsProvide the insulation (myelin) to neurons in the peripheral nervous system.神經(jīng)元和神經(jīng)膠質(zhì)細胞膠質(zhì)細胞優(yōu)秀Neuroglia in the CNS神經(jīng)元和神經(jīng)膠質(zhì)細胞膠質(zhì)細胞優(yōu)

4、秀Able to replicate!Importance in nervous system function is VASTLY underestimated!Evidence is mounting: Nurturing roleSignaling role (Memory?)InflammationPainMany more to come!Neuroglia: Distinguishing Features神經(jīng)元和神經(jīng)膠質(zhì)細胞膠質(zhì)細胞優(yōu)秀Presence of tight junctions between the endothelial cellsOne of the notabl

5、e features of endothelial cells in comparison to other cell is the lack of pinocytic vesiclesSelective permeability to molecules based on their molecular weight and lipid solubilityPresence of specific markersRich in two enzymes: gamma glutamyl transpeptidase (GGTP) (for amino acid transport) and al

6、kaline phosphatase (transport of phsopahte ions) used as marker for BBB.Others: glucose transporter (GLUT-1); endothelial barrier antigen (EBA; unknown function) and antigen recognized by the MRC OX-47 monoclonal antibody (important for cell-to-cell adhesion); transferrin receptor (transport of ferr

7、ic ions).Properties of Blood Brain Barriers神經(jīng)元和神經(jīng)膠質(zhì)細胞膠質(zhì)細胞優(yōu)秀BBB神經(jīng)元和神經(jīng)膠質(zhì)細胞膠質(zhì)細胞優(yōu)秀1. Neurons have TWO processes called axons and dendrites. Glial cells only have ONE. 2. Neurons CAN generate action potentials. Glial cells CANNOT, however, do have a resting potential. 3. Neurons HAVE synapses that use ne

8、urotransmitters. Glial cells do NOT have chemical synapses. 4. Neurons do NOT continue to divide. Glial cells DO continue to divide. 5. There are many MORE (10-50 times more) glial cells in the brain compared to the number of neurons.Glia are different from neurons:神經(jīng)元和神經(jīng)膠質(zhì)細胞膠質(zhì)細胞優(yōu)秀Nerve Cells神經(jīng)元和神經(jīng)膠

9、質(zhì)細胞膠質(zhì)細胞優(yōu)秀Neurons, Glia, Extracellular Space, and Blood神經(jīng)元和神經(jīng)膠質(zhì)細胞膠質(zhì)細胞優(yōu)秀Bidirectional Communication Partners in the CNSReceiving signals from neighboring neurons and responding to them with release of neuroactive substancesExpress receptors for almost all neurotransmitters and neuromodulatorsIncrease

10、of intracellular calcium concentrationMembrane depolarization in astrocytes are common responses to neural activityMetabolically coupled to neural activity神經(jīng)元和神經(jīng)膠質(zhì)細胞膠質(zhì)細胞優(yōu)秀Metabolism of Astrocytes and their Metabolic Cooperation with Neurons Glucose Amino acid metabolism Enzymes:glutamine synthetase(

11、glutamate-glutamine cycle);glycogen phosphorylatase (glycogen mobilization); pyruvate carboxylase (anaplerotic synthesis of oxaloacetate); cysteine sulfinate decarboxylase (synthesis of taurine); glycine cleavage system, glycine metabolism. 神經(jīng)元和神經(jīng)膠質(zhì)細胞膠質(zhì)細胞優(yōu)秀Three Types of Metabolic Cooperation of Astrocytes and NeuronsSupply of the energy substrate lactate to neuronsTh