1. NEURAL TRANSMISSION Neurons Electrical and Chemical Transmission

2. Neurons

3. Neurons

4. Glial Cells Astrocytes –Contact blood vessels and neurons –transport chemicals from blood to neurons Oligodendrocytes –Myelinate CNS axons Schwann cells –Myelinate PNS axons –Guide regeneration after damage Radial glia –Guide neural migration during development

5. CELL MEMBRANES Membrane Structure –Semipermeable lipid bilayer –Proteins Ion channels Transport pumps Receptors

6. MEMBRANE POTENTIAL

7. Electrochemical Gradient –Electrostatic Forces Electrical gradient Opposite charges attract, Same charges repel –Diffusion Forces Concentration gradient

8. RESTING MEMBRANE POTENTIAL Diffusion Forces –Na + and Cl - in –K + out Electrostatic Forces –Na + and K + in –Cl - out +

9. MEMBRANE POTENTIAL Na+/K+ Pump –Compensatory Mechanism –Active when intracellular Na+ high –Neutral or inactive when intracellular Na+ low

10. ACTION POTENTIAL

12. CONDUCTION OF A.P.

13. SYNAPTIC TRANSMISSION NEUROCHEMICAL SYNAPSES

14. SYNAPTIC COMMUNICATION POSTSYNAPTIC POTENTIALS –Excitatory PSP –Inhibitory PSP Electrical Synapses –Gap junctions Neurochemical Synapses

15. Structures of Neurochemical Synapses Presynaptic Membrane Postsynaptic Membrane Synaptic Vesicles Synaptic Cleft Receptor Sites

16. Steps In Neurochemical Transmission SynthesisStorage Neurotransmitter Release Receptor Activation Neurotransmitter Deactivation –Enzymatic Deactivation (Metabolism) –Reuptake

17. Steps in Neurochemical Transmission

18. SYNTHESIS

19. Receptor Activation Ionotropic Receptors –ligand gated ion channels Metabotropic Receptors –G proteins –Second Messengers

20. Neurotransmitter Inactivation  Enzymatic Degradation (Metabolism)  Acetylcholine is inactivated by an enzyme, Acetylcholinesterase (AChE).  The monoamines are inactivated by the enzyme, Monoamine Oxidase (MAO)  Catecholamines (DA, NE, E) are also inactivated by and Catechol-O- Methyltransferase (COMT).  Reuptake  The monoamines are also inactivated through reuptake.

21. MAJOR NEUROTRANSMITTERS Acetylcholine Monoamines Monoamines –Catecholamines EpinephrineNorepinephrineDopamine –Indoleamines Serotonin Amino Acid Transmitters Amino Acid Transmitters –Glutamate, Aspartate –GABA, Glycine Neuropeptides –Enkephalins –Endorphins

22. Cholinergic Pathways

23. Dopaminergic Pathways

24. Noradrenergic Pathways

25. Serotonergic Pathways

26. Neurochemical Pathways Dopamine –Nigrostriatal Pathways (Substantia Nigra  Basal Ganglia) –Mesolimbic, Mesocortical Patways (VTA  NAc and pfCTX) –Most widely studied neurobiology theory of drug dependence relates to dopamine

27. Neurochemical Pathways Acetylcholine –Pontine nuclei involved in components of REM sleep –Basal Forebrain Reduced quantities found in Alzheimer’s patients Norepinephrine –Locus Coeruleus  Forebrain Stimulant drugs may induce wakefulness through these pathways

28. Neurochemical Pathways Serotonin (5-HT) –Raphe Nuclei –Research on weight control, aggressiveness, and depression are centered on 5-HT GABA –Widespread in CNS – Related to seizures Endorphins –Spinal cord and midbrain –Involved in body’s natural mechanisms for pain relief