Bio psych 1


Cells of the nervous system 


Endoplasmic reticulum - reticulum = mesh


Smooth is lipid synthesis and rough has ribosomes for protein synthesis


Specialized cell of your nervous system - neuron


  • Dendrites receive information, Afferents 

  • Axons delivers, Efferents (effects)

  • Axon - terminates in the terminal buttons, ends of finger like structures at the base of axon

  • Axon surrounded by myelin sheaths, insulate and increase speed of neurotransmission 

  • Part of axon connected to the body is called axon hillock, action potential originates, trigger zone


NERVE -

  • Neuron is a connection of nerves

  • Bundles of cable like structures


Neurons - Sensory, Motor, Interneurons (connects motor and sensory)


Sensory - Sense organs to the brain 


Motor - brain back to the sense organs


                        Sensory to motor and motor to sensory is called reflex arc 


Synapse is a close contact link between two neurons 


The neurotransmitters are in synaptic vesicles sent through the axon through the synapse to the next neuron


Anterograde transport is forward, retrograde is backwards (back up to soma)


Communication between neurons is an electrochemical process



Glial cells - gaps between neurons


Phagocytosis - eats the waste of dead or broken neurons


Oligodendrocytes produce myelin sheath - Central Nervous System,, Schwarm cells do this in Peripheral Nervous System


Gaps between myelin sheath called node of ranvier - purpose: saltatory conduction, where the action potential jumps, myelin sheath allows jumps which increases speed


Multiple sclerosis is an autoimmune attack of myelin in the CNS, cells are attacking themselves



ElectroChemical communication



  • Done by generation of action potentials 

  • Sodium, potassium, chloride and calcium ions around the neuron

  • - 70 mv potential in a resting neurons because there is more sodium outside than inside 

  • The -70 will moves towards the positive outside (+10, +40), called depolarization which leads to excitatory potential

  • If it moved towards more negative, called hyperpolarization, which results in inhibitory potential



Sodium potassium pump pushes sodium and potassium ions into and out of the cells

  • 3 sodium out and 2 potassium in (all are positive, meaning the inside will be negative cuz less positive are inside)


Peak of action potential is +40, when the sodium channels close


-70 to +40 depolarization

+40 to -70 repolarization 

-70 to more negative is hyperpolarized 


Once it hits -55, threshold is hit and Na+ opens to get to +40 


In the synapse, the transmitters are released from the vesicles and sprinkled into the synapse 


  • Afferent, Presynaptic terminal is in the terminal button of the neuron releasing the neurotransmitters

  • Efferent, Postsynaptic terminal is the terminal button receiving them 

  • Lock and key mechanism, only certain transmitters can enter certain spots of the postsynaptic terminal 

  • Synaptic cleft is the gap in the synapse



Transmitter functions - don’t want waste or hyperactivity

  1. Sit on the receptor

  2. Reuptaken

  3. Digested - degraded 


All or none law -

  • Stays at the same potential rate, doesn’t decrease along the axon


Axodendritic is a synapse is between a dendrite and axon 

Axoaxonic is a synapse between 2 axons, (terminal buttons of them)


Ionotropic receptor - connects to the binding site, and the channel opens, and the ions flow through


Metabotropic receptors - attaches to a binding site, binding site changes shapes to trigger G protein which excites second messenger, full chain 




ESPS - excitatory              ISPS - Inhibitory 



Neural integration is excitatory and inhibitory 



Neuromodulators - will bring action in the future because they travel farther 





Sympathetic is excited autonomic sensory organs, increased heartbeat

Parasympathetic inhibits, relax and slow heart rate



Dorsal root ganglion is a lump: of a bundle of neurons  (cell body of the sensory neurons in the spinal cord)


 Neurotransmitters - 


Sympathetic - norepinephrine 

Parasympathetic - acetylcholine



Forebrain  - Thalamus, Hypothalamus, Cerebral cortex, hippocampus, basal ganglia

Midbrain - tectum, tegmentum, superior colliculus, inferior colliculus, substantia nigra

Hindbrain - medulla, pons, cerebellum 


(know scientific names ) not listed



Medulla (extension of spinal cord, on top) - vital reflexes: breathing, sneezing, coughing, salivation, heart rate, vomiting 


Cranial nerves exit medulla and control muscle movements in the head and other parasympathetic things 


(Know names and functions of Cranial nerves, and numbers)


Abducens is specifically lateral eye movement (not that deep ur fine)



PONS - connects nerves from the brain to the rest of the body (right controls left and so forth)

Pons = bridge



Cerebellum=balance; shifting attention between auditory and visual stimuli


MIDBRAIN

Tectum = roof 

Superior (vision) and inferior (auditory) colliculus = sensory information processed 

Tegmentum = contains nuclei for cranial nerves and part of the reticular information (the floor)

Substantia nigra (black when stained during studied)- gives rise to the dopamine containing pathway facilitating readiness for movement 


 Person with muscle issues like parkinsons will have issues in substantia nigra 


Used to study these parts of the brain by doing autopsies of people with specific issues 


Forebrain - Folds in the parietal lobe and frontal lobe 

  •  Pre central gyrus (frontal) planning 

  • Central sulcus (middle)

  • Post central gyrus (parietal lobe) motor control 



Limbic system; Hippocampus (memory), amygdala (emotion), hypothalamus (metabolism, eating, drinking, sex), cingulate gyrus (above thalamus, around the corpus callosum; higher order functions), Olfactory bulb (smell)



In the limbic system, temporal lobe contains hippocampus and amygdala 

  • Kliiver and Bucy did monkey temporal lobotomy and they became fearless 


Thalamus is relay station (above hypo)

Hypothalamus - convey messages


Diencephalon is both thalamus and hypothalamus 


Nucleus Basalis - arousal wakefulness and attention 




Frontal - planning/execution 

Parietal - motor control, somatosensation in there (motor and sensory)

Temporal - auditory and memory (hippocampus and amygdala)

Occipital - vision






Large cerebral ventricles for schizophrenics - large means that that the other parts of the brain are overtaken by it and therefore they have less cerebral cortex


Meninges are membranes that surround the brain and spinal cord 

 



DEVELOPMENT of the brain -


Nervous system develops are 2 weeks in the womb



  1. Proliferation - growth, production of new cells (neurons), stem cells are core cells that keep on dividing 

  2. Migration - movement of the neurons and glia to their eventual locations, some don’t get there until adulthood, chemicals like immunoglobulins and chemokines help guide them 

  3. Differentiation - forming of dendrites and axons to function specifically for the part where they are

  4. Myelination - glia produces the myelin around the neuron, come from fatty food, occurs first in the spinal cord 

  5. Synaptogenesis - form the synapses, occurs throughout life, slows as you get older 

(order is important)



Originally thought that no neurons were created after early development but research suggest that stem cells (undifferentiated) can create daughter cells that can transform into glia or neurons 


New olfactory receptors also continually replace dying ones 


Skin cells are the newest, heart cells are usually as old as the person

Cerebral cortex tends to not form any neurons after birth



Post synaptic cells strengthen connection with some cells and eliminate connections with others



Neural darwinism - 

  • We form more connections that we need and the ones who are successful and prosperous will survive while others fail


NGF - nerve growth factor         BDNF - Brain derived growth factor 


  • Type of protein released by muscles that promotes growth of axons 


The brain will overproduce neurons and apoptosis the dysfunctional ones 



Neurotropins are chemicals that promote survival and activity 



Neuronal death

  • Blind people can't get rid of ineffective axons 


Teratogens (chemicals, drugs, alcohol, radioactivity) are toxins that affect ur develop brain 





Fetal alcohol syndrome - 

  • Hyperactivity

  • Motor issues

  • Difficult attention 

  • Degrees of mental retardation

  • Facial abnormalities


Their dendrites are short and don’t have lots of connections (less excitation and less neurotrophins)\

  • Suppressed Glutamate (major excitatory neurotransmitter) 

  • Increased GABA (major inhibitor)





Differentiation in the cortex 

  • Each neurons are in different shapes and make ups in different parts of the brain 

  • Developing neurons will have the properties of their location 

  • Neurons transplanted later will develop some new properties and keep some old


Ur brain can reorganize by experience

  • Structures of neurons will modify

  • Dendrites new spines

  • Gain and loss of spines indicates new connections which relates to learning 




Thicker cortical areas, more synapses, more dendrites indicate enrichment


Critical period = stages of development when most development happens 






Radial arm maze is an 8 arm maze used to train rats over time, teaching them to learn 

  • If u damage the hippocampus with a lesion (burn) they have unlearned everything 

  • It will eventually begin to relearn some parts, might take longer 




Plasticity - the brain's ability to change and repair itself 

Temporal lobe of professional musicians is 30% larger on average 

Thicker gray matter from their repeated exercise of the skill and body control


Kids are impulsive because the limbic lobe is developing at a faster rate the the frontal lobe 





Adult brain - 

  • More cognition and now the development plateaus 

  • Will decline starting around 60-70 


The curve is like a hill from childhood to elderly 




Crystalline intelligence is the facts is mostly maintained


Fluid intelligence - speed, learning new things (THIS IS WHAT DECLINES) 







Plasticity after brain damage-



Edema is fluid in the brain that increases pressure as a result of the ischemia or hemorrhage 

Sodium potassium pump is putting too much potassium inside 



Cooling brain is a good solution to anti inflame 







Axon sprouting = Collateral sprouting 



Lamarckism - if u dont use it, you lose it (humans with tails)