1. Nervous System

2. -Central Nervous System -Peripheral Nervous System Brain Spinal Cord Cranial Nerves Spinal Nerves Peripheral Ganglia Division of the nervous system

3. -Central Nervous System -Peripheral Nervous System Brain Spinal Cord Cranial Nerves Spinal Nerves Peripheral Ganglia Division of the nervous system

4. Central Nervous System (CNS) 7 Main Parts of the CNS Spinal Cord Medulla oblongata Pons Cerebellum Midbrain Diencephalon Cerebrum

5. Directions in the nervous system - Axes Orientation Axes in the brain Rostral-Caudal (front-back)  anterior-posterior Dorsal-Ventral (up – down) Lateral-Medial (sideways – mid)

6. Directions in the nervous system - Planes

7. Maturation of the CNS Brain weight at birth: 400 g At 2 years ~ 1000 g Adult ~1500 g Maturation is mostly based on differentiation of nerve- cell connectivty

8. Nerve cells (neurons)

9. Sketch of a neuron Nucleus Dendrites Myelin Axons Dendrites -- Input Cell body (soma) -- Integration Axon -- Output

10. Structure of neurons - Dendrites At dendrites, the neurons recieve input via axons of other neurons at synapses dendritic spine

11. Structure of neurons - Soma In the soma of the cells, the cell nucleus is located (containing the DNA, i.e. genetic code); the synthesis of the proteins (within ribosomes and endoplasmatic reticulum) as well as energy production (mitochondria) are performed.

12. Structure of neurons - Axon The axon transmits the information electrically from the soma to the synapses – it is surrounded by myelin that insulate the axon, provided by oligodendrocytes (glial cells)

13. Sketch of a neuron Nucleus Dendrites Myelin Axons Dendrites -- Input Cell body (soma) – Integration; protein production, genes, energy production Axon -- Output

14. Electrical properties of neurons The cell membrane isolates the intracellular from extracellular space extracellular intracellular

16. Electrical properties of neurons The membrane potential In the resting state, the intracellular space contains more negative ions than the extracellular space extracellular intracellular difference of -70 mV

17. Ion channels connect the intra- and extracellular space Opening of ion channels lead to a flux of ions through the membrane and to a change of the membrane potential

18. Different types of ion channels

19. The action potential The action potential is generated by ion flux through voltage gated channels All or nothing principle!!

20. Propagation of the action potential

21. Synapse – Communication between neurons

23. Presynaptic vesicles with neurotransmitter Released transmitter Transmitter binds to receptor Na + Transmitter- Resorption from synaptic cleft Synapse – Communication between neurons

24. Animasi

25. Excitatory and Inhibitory Synapses Depending on the neurotransmitter and the receptor, the postsynaptic potential can be excitatory or inhibitory Excitatory postsynaptic potential (EPSP) Inhibitory postsynaptic potential (EPSP)

26. Important Neurotransmitters Dopamine Epinephrine Norepinephrine Acetylcholine Serotonine Glycine GABA Glutamate

27. Two forms of integration of information

28. EPSC at dendrite can lead to action potential

29. Effect of inhibition on excitation

30. Glial cells astrocytes oligodendrocytes

31. Astrocytes Astrocytes connect the extraneuronal space with the blood vessels

32. Oligodendrocytes Oligodendrocytes sheat the axons of the neurons to increase conductance of action potential

33. Summary neuronal communication intracellular electrical transmission of information (action potential) neurons communicate via biochemical transmission (neurotransmitters and receptors) integration of information in neurons by means of spatial and temporal summation