Neuropsychology

Class 9

             I.      Neuron Hypothesis

A.   What defines a cell?

                                                           1.      The Basics of Cells

                                                           2.      The plasma membrane

 

B.   Unique Structure of the Neuron

                                                           1.      Neuron structure tutorial at http://psych.hanover.edu/Krantz/neurotut.html

                                                           2.      General parts

                                                           3.      Axonal Cytoskeleton

                                                           4.      Axoplasmic transport

C.   Importance of this Concept

                                                           1.      Why might the cell doctrine in biology be important for us?

                                                           2.      What is the importance that this can be applied to the nervous system?

          II.      Genetics Review -DNA

A.   Transcription

B.   Translation

C.   Protein structure

HOMEWORK:  calculate and show answers for Nernst and Goldman equations.  Concentrations and permeabilities are here.  Be prepared to show work in class.

B.   Unique Structure of the Neuron

                                                           1.      Neuron structure tutorial at http://psych.hanover.edu/Krantz/neurotut.html

                                                           2.      General parts

                                                           3.      Axonal Cytoskeleton  

                                                           4.      Axoplasmic transport

          C. Glial Cells

               1.  Astrocytes

            2. Myelin Cells

                    a. Oligodendrycytes

                    b. Schwann Cells

3.     Blood-Brain Barrier

III.      Basic Chemistry

A.   ISSUE: All neural membrane potentials are the product of basic physics and chemistry

B.    Atoms and Binding

1.                 The atom

a)                 The nucleus

b)                The electron shell or cloud

(1)              A full ring

(2)              A partially full ring

2.                 Binding

a)                 Ionic binding and ions:

(1)              Electron from one atom joins other atom, both become charged.

(4)              

(5)              

(6)              In solution, ions will tend to wander a part

b)                Covalent binding and "sharing electrons":

(1)              Electrons are shared - tightly bound -

(2)              Generally, atoms cannot separate until bond is broken

C.   Concentration: amount of substance per volume.

1.                 Atoms do not move purposively

2.                 Chemicals will flow from high concentrations to low with effect of evening out concentration: by random movements: Diffusion

D.   Entropy

1.                 A definition of entropy: no differences anywhere

2.                 That entropy increases is the second law of thermodynamics

3.                 Thus diffusion increases entropy

4.                 Enthalpy: DEF: forces that can lead to organization

E.    Application of Chemistry to Membrane

1.                 Channels in the Membrane

2.                 What channels are there

F.    Charging the membrane

1.                 Charge gradients vs. diffusion gradient.

a)                 E.g. potassium

b)                The Nernst Equation for potassium

              EK = 58log([K]o/[K]i) = -93 mV

c)                 Nernst Values for other ions

(1)              ENa = + 56 mV

(2)              ECl = - 66 mV

d)            Getting to -70 mV

(1)              The Goldman equation

           Em = 58log(PK*[K]o+PNa*[Na]o+PCl*[Cl]i)/
                          (PK*[K]i+PNa*[Na]i+PCl*[Cl]o)

(2)              Permeability = the ability of an ion to reach equilibrium

(3)              Gets us to -67

(4)              The Sodium Potassium Pump

(a)              3 NA/2K

(b)             gets us to -70

(c)              Uses energy