III (occulomotor)

VII (facial)

IX (glossopharyngeal)

X (vagus)

31 total 

Cervical 8

Thoracic 12

Lumbar 5

Sacral 5

Coccygeal 1 

Visual and auditory reflexes

Reward and motivation 

Cerebral hemispheres

Basal ganglia

Diencephalon 

Thalamus - sensory relay (except for olfactory)

Hypothalamus - hormones, appetite, sexual behavior, thirst, homeostasis

Frontal lobe: planning, cognition, motor control

Parietal lobe: association area, sensory input

Occiptial lobe: vision

Temporal lobe: audition, memory consolidation 

1) buoyancy

2) communicates with brain's ECF and may play a role in carrying waste products

3) conduit for hormones and GFs

4) diagnostically valuable 

What is the source of the CSF?

What volume of CSF is release each day?

The choroid plexus found in the ventricles;

500 mL/day 

Too much CSF in ventricles caused by:

1) a blockage within ventricles

2) increased production (choroid plexus tumor?)

3) block of venous outlet 

- Proteins via lysozomes to be degraded

- Neurotrophic factors for development (ie nerve growth factor)

- Viruses 

Short - 30-40 microns which are good for local control

Long - 1-1.5 meters from cortex to spinal cord for motor control 

Bipolar, multipolar, pseudounipolar;

Multipolar 

Astrocytes

Oligodendrocytes (CNS) / Schwann cells (PNS)

Microglia - phagocytic

• Structural support
• Uptake of ions (K+)
• Fill gaps by proliferation (ability to respont to injury by growing to fill sites)
• NT metabolism
• Control blood flow (through prostaglandin release during activity of neuron) 

Barrier - to ion movement

Support - of integral membrane proteins

Storage - of electrical charge 

K+: closed and open

Na+: closed, open and inactive 

Na: initiation and transmission of AP (found in axon)

K: repolarization and hyperpolaraition of AP (found in axon)

Ca: triggers release of NT from vesicles 

During absolute the K channels are open and the cells are repolarizing and hyperpolarizing

Before the relative Na channels are inactivateed and with time during relative refractory period the Na channels close and then can be reopened

Inc number of Na channels

Segments of interrupted myelination 

Small synaptic vesicles

large dense core synaptic vesicles

Differences between chemical and electrical synapses in terms of:

- distance between pre and postysnaptic cell membrane

- cytoplasmic continuity

-synaptic delay 

-direction of transmission 

Elec              chem

  3.5 nm        30-50 nm 

                          yes               no

                     no delay    0.3 msec to several msec                                         (depending on NT)

                     bidirectional    unidirectional

-synthesized in cell body or axon terminal

-present in synaptic terminal for packaging into vesicles

-exogenous application mimics endogenous affect

-specific mechanism for removal of NT from synaptic cleft 

1 - diffusion

2 - enzymatic degradation

3 - reuptake by specific transporters back into presynaptic terminals 

Temporal: summing of PSPs over time

Spatial: summing of many synapses 

Receptor that provides direct coupling between the receptro and the NT ligand gated ion channel

FAST

accomodates more than one type of ion 

Glutamate;

 GABA and glycine

Gray's type I - excitatory with wide synptic cleft ~30 nm or more

Gray's type II - inhibitory with smaller cleft ~20 nm or less 

Voltage gated: 1 ion

Ligand gated: multiple ions (Na K or Ca) 

ligand-gated: Less because it is dependent on amount of NT

voltage-gated: Greater regenerative capacity; depends on change in membrane potential 

Indirectly coupled to ion channels

Slow synaptic transmission

Utilizes a G protein 

1 - close normally open channels

2 - modulate voltage gated ion channels

3 - modulate ligand gated ion channels 

1 - G proteins open channels directly

2 - channel can be modulated by 2nd messenger 

ACh

Amino acids

Biogenic amines

Neuropeptides

Gases

Nucleus basalis and septal nuclei

Excitatory: glutamate and aspartate

Inhibitory: GABA and glycine

Ionotropic - AMPA, NMDA, Kalnate

Metabotropic - Quisqualate

GABA A: ionotropic

GABA B: metabotropic

Benzodiazapines, alcohol and barbituates

(overactivation of the GABA A receptor by these agents causes sleep and then coma)

From what are biogenic amines derived?

SN - substantia nigra, caudate nucleus and putamin

VTA - ventral tegmental area

Cholinergic neurons of the nucleus basalis

locus coerulus (limbic system) --> emotion, mood arousal

spinal cord --> pain modulation

cerebellum --> movement and motor control

sympathetic NS

One hypothesis about schizophrenia is that it is caused by too much:

Where are serotonin receptors located?

In the raphe nuclei of the brain stem (medulla)

spinal cord

limbic structures