1. Epilepsy & Membrane Potentials
EEG WAVEFORM
Ca2+
Neural Recording
Excessive Calcium influx leads to a depolarized Resting Membrane

2. Neurophysiology

3. Anatomy of the Neuron Dendrites Cell Body Axon Hillock (organelles)
= Trigger Zone
Direction of
Action Potential
Axon
Terminals

4. Schwann cells and Nodes of Ranvier
Schwann cells make MYELIN
MYELIN is an electrical insulator
Action Potential “jump” down myelinated axons by SALTATORY CONDUCTION

5. Peripheral Nervous System: Support Cells

6. CNS Support Cells = Neuroglia

7. Action potential propagation along neurons
How does the action potential move from the terminal of neuron 1
to the dendrites of neuron 2?
Direction of
Action Potential
2 main types:
electrical and chemical
SYNAPSE

8. Electrical SYNAPSE Gap Junction
Action potential moves DIRECTLY between neurons
EXAMPLES:
Smooth Muscle
Cardiac Muscle
Gap junction between adjacent cardiac cells

9. Chemical SYNAPSE Presynaptic Terminal Synaptic CLEFT
Postsynaptic membrane

10. Chemical SYNAPSE: Function
1) Action potential down axon to terminal
2) Ca2+ Channel open; Ca2+ influx
3) Vesicles of Neurotransmitters release into synaptic cleft
- 4) Neurotransmitter diffuse into synaptic cleft
- Bind to LIGAND-gated ion channels
on post-synaptic membrane

11. Chemical SYNAPSE: Signal types on post-synaptic membrane
EPSP: Excitatory post-synaptic potential
Mechanism
Ligand-gated Na+ channels OPEN
Importance
Increases likelihood of AP in postsynaptic cell
If ENOUGH neurotransmitters are released….AP

12. Local Anesthetics: Novacain, Lidocaine, etc.
Painful stimulus
Action potential
Sensory Neuron
Blocks LIGAND-gated NA+ channels
NO EPSP……no Action potential on post-synaptic cell……no perception of PAIN

13. Chemical SYNAPSE: Signal types on post-synaptic membrane
2) IPSP: Inhibitory post-synaptic potential
Mechanism
Ligand-gated K+ or CL- channels OPEN on post-synaptic membrane
Importance
Decreases likelihood of AP in postsynaptic cell

14. Presynaptic INHIBITION and FACILITATION: Neuromodulators
Can modulate the ability of a neuron to release neurotransmitter
Neuron
Collateral Neuron
INHIBITION of neurotransmitter release at
POST-SYNAPTIC membrane

15. Clinically important neurotransmitters & neuromodulators
Cocaine
Alcohol
Nicotine
Caffeine
Heroin
Viagara
Marijuana
Morphine
Crystal Meth
LSD
Anti-depressants: Prozac
Strychnine
We will cover how some of these drugs work

16. Neural Summation Spatial Axon hillock SUMS EPSP & IPSP Temporal

17. Functional Organization of Nervous System
Central Nervous System
Brain & Spinal Cord
Peripheral Nervous System
Spinal Nerves & all other nerves
Motor
Sensory

18. Sensory Physiology

19. Sensory Physiology Eye Light 1 3 2 Perception of sensation involves
1) External physical signals
2) Converted by physiological process
3) To neural signals (graded & action potentials)
Eye
Light
Phototransduction
Action Potential
in Optic Nerve 1 3 2

20. General senses
Perceive touch, pressure, pain, heat, cold, stretch, vibration, changes in position
Located on skin and in joints/muscles

21. Cutaneous Somatic Receptors

22. Muscle spindle: stretch receptor

23. Golgi Tendon Organ: Tendon stretch receptor
Sensory Neurons
Collagen Fibers within Tendon

24. Physiology of Cutaneous Receptors
Stimulus (Vibration, Pressure, Temperature, Stretch, etc)‏
Mechanical and/or biomolecules cause opening/closing of ion channels (K+, Ca2+, Na+) on receptor membrane =
Graded Receptor Potential
3. If receptor membrane depolarizes to threshold =
ACTION POTENTIAL

25. Functional classifications of sensory receptors
Sustained Pressure
Pain
Vibration

26. General sensory neural pathways

27. Dorsal Column thalamus Tertiary Neuron Proprioreception, Vibration,
Pressure
Secondary Neuron
Primary Neuron

28. Anterolateral System Tertiary Neuron Touch, Itch, Pain, Temperature
Secondary Neuron
Primary Neuron

29. Blocking Pain Perception
Pressure, Vibration
Pain
Dorsal Column
Anterolateral system
2) Triggered by BRAIN (endorphins)
Heroin & Morphine can trigger
Via Blood
1) Collateral Branch
Triggered by Massage, Exercise :
Presynaptic inhibition of 2nd Neuron in Anterolateral System

30. Sensory Perception in Brain
Somatosensory Cortex (Postcentral Gyrus)
Area on cortex = sensitivity of body part =
# of sensory receptors on that part of body

31. Special senses (located in the head region)‏
Vision
Hearing and equilibrium
Olfaction
Taste
We will ONLY cover Vision as an example of a Special Sense!

32. Eye: Basic Anatomy
Lens
Pupil
Optic Nerve
Retina

33. Retina
Pupil
Lens
Ganglion Cells
Bipolar Cells
Rod & Cones

34. Disk
Rhodopsin

35. DARK cGMP Rhodopsin Transducin (G-protien) cGMP-gated Na+/Ca2+ Channel
K+ channel
Glutamate
DARK
-Rhodopsin: inactive
-Transducin: inactive
Intracellular cGMP levels HIGH
Ion channels are OPEN
Membrane potential = -40 mV
Glutamate release high onto
Bipolar cells!
Bipolar Cells

36. LIGHT cGMP 2 Rhodopsin 1 BLEACHES 3 5 4 Time Bipolar Cell 6 Retinal
Activated Transducin (G-protien)
decreases Intracellular cGMP 2
Opsin
Rhodopsin
BLEACHES
cGMP-gated Na+/Ca2+ Channels CLOSE 1
cGMP 3
K+ channel
-40
LIGHT
Membrane potential (mV)
Photoreceptor 5
Glutamate
decreases
-70 4
HYPERPOLARIZATION
Time
Bipolar Cell 6

37. Cones: Color & Day Vision
Rod: Night Vision

38. Neural pathway to optic nerve & brain
Neural Layer
of Retina
Ganglion Cells
Bipolar Cells
Rod & Cones

39. Neural Pathway in Brain
Optic Chiasm
Optic Cortex
Optic Nerve

40. Neural Processing in BrainV4 V3
Layers of signal processing V2 V1

41. V1 sends projections Dorsal & Ventral
Dorsal Stream: “Where” & “How” Pathway
Ventral Stream: “What” Pathway

42. Color Vision: 3 cone types
Retina

43. Distribution of Rod vs. Cones
# of photoreceptors
Position on Retina

44. Processing Visual Stimuli
Retinal Processing:
Convergent Neural Network!
1 million ganglion cells!
200:1
Amount of convergence
125 million photoreceptors!
1:1
Position on Retina

45. Brain Commands to Muscle
Neural Networks
Brain Commands to Muscle
(Motor Output)
Vision

46. Circadian Rhythms: Why you get tired when its dark!
Suprachiasmatic Nucleus (SCN)
Melanopsin
Rhodopsin