1. Introduction and organization of Nervous system

2. Nerve signal processing

3. Sensory processing : Physical, chemical, EM

4. Motor control mechanism voluntary and involuntary

5. Consciousness, sleep, emotion reproduction

6. Cognitive function: Language, Memory…

7. Development of NS and Genetics

8. Cognitive Neurophilosophy

9. Recent development

Objectives

Nerve Cell

Ion distribution across cell membrane

A. Effect of concentration difference B. Electrical potential difference affecting negative ionsC. Pressure difference

Ion movement across cell

Giant Nerve Cells of Squid

Resting membrane Potential

Patch-clamp setup

A pipette containing

acetylcholine (ACh) is

used to record

transmitter-gated

channels in skeletal

muscle. (Adapted

from Alberts et al.

1989.)

Action Potential

Propagation of AP

Saltatory conduction

The Refractory Period

Synapse

Electrical synapse

Chemical Synapse

Neurotransmitter release

Post synaptic receptor

Depolarization & Repolarization of Post Synaptic Neuron

Excitatory and Inhibitory Post Synaptic Potential

Excitatory and inhibitory currents have competitive effects in a single nerve cell. (Adapted from Eckert et al., 1988.)

Second Messenger

Stretch Reflex

Inhibition

Reverberatory (Oscillatory) Circuit as a Cause of Signal Prolongation.

Neurotransmitters

1. The substance must be present within the presynapticneuron

2. The substance must be released in response to presynaptic depolarization, and the release must be Ca2+-dependent.

3. Specific receptors for the substance must be present on the postsynaptic cell

Major classes of NT

Neruopeptide

Acetyl Choline

Cholinergic Receptors in Normal Brain

Alzheimer's disease

Serotonin System

•originate in the median raphe of the brain stem

•project to many brain and spinal cord areas, especially to the dorsal horns of the spinal cord and to the hypothalamus

•acts as an inhibitor of pain pathways in the cord, and an inhibitor action in the higher regions of the nervous system

•believed to help control the mood of the person, perhaps even to cause sleep.

Dopamine System

•secreted by neurons that originate in the substantia nigra.

•The termination of these neurons is mainly in the striatal region of the basal ganglia.

•The effect of dopamine is usually inhibition

•Parkinsonism is due to degeneration of substantia nigrawith reduced dopamine

•Schizophrenia there is increased dopamine

Norepinephric System

•secreted by the terminals of many neurons whose cell bodies are located in the brain stem and hypothalamus•help control overall activity and mood of the mind, such as increasing the level of wakefulness•In most of these areas, norepinephrine probably activates excitatory receptors, but in a few areas, it activates inhibitory receptors instead•Norepinephrine is also secreted bymost postganglionic neurons of the sympathetic nervous system, where it excites some organs but inhibits others

Glutamate System

•the prominent glutamatergicpathways are: the cortico-cortical pathways; •the pathways between the thalamus and the cortex; and the extrapyramidal pathway o•other glutamate projections exist between the cortex, substantia nigra, subthalmicnucleus and pallidum. •Glutamate is an excitatory neurotransmitter

GABA System

•Widespread in the brain and spinal cord•Inhibitory by increasing permeability to Cl

Nerve Conduction Study

Transcranial Magnetic Stimulation

SSEP

Auditory Evoked Response

BAEP

VEP

Selected Reading