Neuroscience

• 10-50 times more gila than neruons 
• supporting cells 

• support
• clean up(dead cells and waste) 
• regulation 
• blood brain barrier 
• nourishment 

• folowing trauma they engulf and breakdown dead and dying neurons 
• active following injuring, infection or stroke (like the wbc of the brain) 
• little known of function at resting state 
• role in diseases MS AIDS PD and Alzheimers 

• Oligodendroytes 
• schwann cells 
• astrocytes 

• funtion: insulation of axons= myelin sheath 
• Oligoes---CNS 15 axons
• schwann PNS only 1 axon 

• function: Nutrients(provide and connect) 
• BBB 
• neurotransmitter removal 
• clean up gets rid of scar tissue 
• support 
• CNS 
• doesn't form mylien sheath 

semipermeable barrier produced by the cells walls of the capillaries in the brain 

tight junctions between cells making it difficult for some substances to pass from the blood stream to the brain 

• gases and water diffuse readily
• some drugs: loperamind vs morphine ...herion passes faster than morhpine 
• alcohol 

• energy sources: glucose, amino acids 
• ions(na+ k+cl-) 
• vitamins some hormones and peptiedes 
• gets acrsoss through astroyctes 

• BBB is weaker in some areas of the brains capillaries 
• area postrem located in the brain stem(vomit reflex) 
• pituitary gland(hormone release) 

• basic unit of the nervous system 
• specialized cells that recieve info and transmit it to other cells by conducting electrochemical impulses 

• Nucleus--dna 
• endoplasmic reticulum--ribosomes 
• mitochondrion--energy 
• plasma membrane ---lipid bilayer studded with protein comples impermeable 
• cytosketleton 

• Branching 
• reflects communication property 

cell body, nucleus, er, mitochondria 

recipeients of messages from other neurons 

simgle process  that leaves the soma and carries messages to the trminal buttons (to other neurons ) 

insulation to carry message more efficeitly 

branches at the end of the axon where neurotransmitters are releases 

 junction between terminal button of one axon and teh membrane of anohter neroun 

• lots of mitochrodra 
• need a lot of glucose and 02 
• but have little ability to store enregy 

• esp in adults 
• don't replicate very often 

info processing an transmission

• invertebraes --communication 
• simpliest 
• 1 primary process to many branches 

• processing sensory neurons 
• soma to 2 processes 

• most common 
• CNS spinal cord and brain 
• single axon many dendrites 
• multipolar interneuron don't have a defined axon signal motifiers to spinal cord 

info from external environment 

CNS to muscles and glands 

• Lie completely in CNS  
• Function: perceiving learning decision making complex behaviors 

electrical signals witin a neuron flow in one direction:from reveiving site to axon, From there AP is unidirectional axon to presynaptic terminal 

neurons do not connect indiscriminately with one another to form random networks each cell maes specific connections 

charge across the neurons membrane created by electrical polarization 

• outside of the neuron is postive inside is negative 
• represented with - -(70mV) 

• resting membrane (-70mV) 
• depolarization--increase in the membrane potential( inside becomes more like the outside ) towards 0 EXCITE 
• hyperpolarization ---decrease in the membrane potential (inside becomes more negative) INHIBIT

•  ions(charged particles) are balanced inside and outside of the cell 
• cations:positvely charged 
• anions negatively charged 

• membrane is somewhat permeable to NA=and K= 
• na+ outside: force of diffusion want Na+ to come in 
• k+ inside:force of diffusion want K+ to go out 
• electostatic pressure: like repels like (electrostatic gradient ) 

• na/k pump
• protein in cell membrane that moves k in 2 and na= in 3 using atp 

• net result of diffusion and na/k pump is resting membrane potential 
• na outside wants in 
• k inside wants out 
• Na just waiting for the membrane permeability to increase 

• brief change in the permeability of the membrane such that the mebrane potential depolarizes 
• stimuli from other neurons open ion channels 

• na channels open first and na rushed into the cell 
• k channels open later and k rushes out of the cell 
• the cell depolarizes 
• (membrane potential becomes more positve more positive inside the neuron) 

• when cell is depolarized 
• na channels close 
• k channels stay open though 
• then the na/k pumps restores resting potential 
•          requires a lot of energy3 na go out 2 k pumped in 

• na channels 
• novocain, cocaine, lidocaine block na channels to prevent depolarzation (tempory and local) 

• tetrodotoxin 
• pufferfish, sewts and frogs 
• permanent blockers of na channels 

the passive conduction of electrical current in a decremental fashion, down the length of an axon 

conduction of action potentials by myelinated axons the action potential apperars to jump from one node of Ranvier to the next  

• energy
• a. less atp requried to pump na out and reset the system 
• speed 
• a. transmission under mylein sheath is much faster 
• roughly 90 ms vs 10-20ms 

• when action potential reaches terminal buttons, what happens? 
• electrochemical transmission ---electric=action potential 
• chemical=neurotransmitters 
• neurotransmitters chemicals that communicate between neurons at the synapse 

the location on a receptor protein to which a ligand binds 

a chemical that binds with the binding site of a receptor 

a small hollow bead like structure found in  terminal buttons, contains molecules of a transmitter 

• ligand dependent ion channel
• ion channel that opens when a nT binds to it (fast) NT depended 

• receptor is adjacent to ion channels 
• when nt binds it causes a cascade of intracellular events that open nearby ion channels (slower)

determine gender in babies ...digestion

• reuptake=NT is taken up by the presynaptic cell via a membrane transporter 
• metabolism(enzymatic degredation)=NT is broken down in the synapse 
• autorecptors=resynaptic receptors that detect the level of NT in the synapse 

• intensity of nervous systems response is regulated by rate ( how many neryons fire ) 
• most neurons fire at a basal rate all the time (stimuli can excite--increase firing) or inhibit 

• excitatory post-synaptic potential(EPSP;+) 
• inhibitory post-synaptic potential(IPSP;-) 

how many +- inputs the neruon recieves and whether they occur at the same time 

spatial summation 

toward teh back, top of hand and back 

towards the belly 

towards the face 

towards the tail 

toward the midline 

away from the midline 

ear to ear 

between the eyes 

like taking off a hat 

both sides 

on opposite sides (vison) 

on the same side 

brain and spinal cord 

• cranial nerves 
• somatic ns 
• autonomic ns 
•   sympatheicNS (fight or flight) increase pulse 
•    parasympathtic 

3 layers of protective sheaths around the CNS 

• hard mother 
• outer layer 
• thick tough but flexible 

• web like 
• soft and spongy 
• only in CNS 

inner thin layer that continues around the NS 

hollow spaces in the brain that contain CSF

clear fluid that fills the subarachnoi space and the ventricles of the brain and spinal cord 


supports and protects teh brain from damage and its own weight 

 csf is produced by a special sturctre in the ventricles called the choroid plexus 

• entire volume replaced every 6 hours 
• fluid fills the ventricles and surrounds the brain
• desends into a tube in the center of the spinal cord central cannal 

• Choroid plexus 
• lateral ventricle 
• 3rd ventricle cerebral aqeduct 
• 4th ventricle 
• subaranoid space ---central canal 
•                arancoid villius /granulations 

links the pns to the brain(not the crainal nerves) 

axons carrying info up or down 

cell bodies 

Central canal=filled with CSF

• relay of sensory signals to cns and motor signals from cns to skeletal muscles 
• sensory nerves--enter dorsal side of spinal cord 
• motor nerves---exit ventral side of spinal cord 
• cranial nerves--leave right to the brain 

• automatic 
• regulates cardiac muslces smooth muscles and glands 

• sympathetic NS fight or fligh energy use 
• parasympathetic --resores/maintains homeostatis 
• energy saving 

System of glands that release hormones under the direction of the pituitary gland

Hormones --chemical messengers that travel through the bloodstrem(loose junctions..pitutary )

• Hormones can have effects on the CNS
• Can easily cross the BBB (feedback system)
• Bind to both

• Membrane-bound receptors
• Intracellular receptors (transcription factors… make new proteins)

controling vital functions heart rat resp vomit cough sneeze reflexes muscle tones 

• reticular formation--extends from medulla through the pons to midbrain 
• controls sleep/wake cycle 
• alterness to external stimuli 
• norephinephrene projections throughout the brain

• raphe system(nuclie)--control of internal alertness
• mental vigilance 
• serotonergic projections throughout the brain 

• coordinations of voluntary movement complicated motor movement 
• imput from motor cortex spinal cord sensory neurons and inner ear 

Tectum (above cerebral aqueduct)

Superior & inferoir colliculi--visual and auditory reflexes(something out of the corner of your eye) 


Tegmentum (below cerebral aqueduct)

• Cerebrum: cerebral cortex (bark)
• 4 lobes

• Frontal-judgement, iniciates movement
• Parietal--sensation
• Occipital--vison
• Temporal--hearing 

• groove in the surface of teh cerebral hemisphere 
• smaller than a fissure 

• major groove in teh surface of the brain 
• long deep cut 

• convoltion of the cortex of teh cerebral hemisphere separated by sulcus of fissure 
• big bumps 

primary visual cortex

The region of the ___back of the brain upperand lower banks of calcarine fissure_ whose primary input is from the visual system.

primary auditory cortex

The region of the ___lower surface of lateral fissure__ whose primary input is from the auditory system.

lateral fissure--The fissure that separates the temporal lobe from the overlying frontal and parietal lobes.

primary somatosensory cortex

The region of the ___caudal to central suclus__ whose primary input is from the somatosensory system.

primary motor cortex

The region of the _posterial frontal lobe__ that contains neurons that control movements of skeletal muscles.

• Corpus callosum = commissure 
• connection between teh 2 cerebral hemisphers 

Thalamus = sensory relay station (train station) connects body senses to the cerebrum

• Lateral geniculate nucleus = eye to CTX
• Medial geniculate nucleus = ear to CTX

• Hypothalamus
• involved in everything regulate temp and hormone production

• limbic system(motivation, emotion, memory ) 
• amygdala( almond shaped, anterior temporal lobe) 
• fear anger emotions defensive and agressive behavior at tip of hippocampus 

hippocampus--learning declaritive momories shaped like a ram horn 

fornix--connects hippocampus to other parts of the brain 

Basal Ganglia (3 seperate group of cells)

• Caudate nucleus
• Globus pallidus
• Putamen--important parts of the motor system control of balance and movement connected to substantia nigra 

Connect to substantia nigra (nigrostriatal DA pathway) and motor areas of CTX