Tim-principles Of Neuroscience Flashcards
Galileo views
Link between mind and brain, the world is heliocentric, heart mentioned more than brain in the bible
philosophical standpoints- ancient Egyptians
Ancient Egyptian 1600bce-300bce, brain written on pyrus, damage causes change in behaviour. Left heart as the only organ in the body as heart weighed in the afterlife against feathers but didn’t care about the brain
Ancient Greece
Plato and Aristotle 429-322 bce. Plato said mind has 3 parts (higher thinking, emotions and Eros/desire). Aristotle said sensus cominus (common sense where they come together). Source of sensation is heart as first to develop, die immediately, central . Psyche and Eros - Eros mum is Venus, psyche is pretty, Venus gets jealous and gets psyches father to be eaten by monster (mind is immortal)
Hippocrates and materialism 400 BCE-100ACE:
feelings arise from the brain and the brain alone. Galon: physician for the gladiators, brain injuries had behaviour deficits. Noticed nerves went to diff parts of the body. The 4 humours were sent from the brain via these nerves- led to diff personalities/ mental illnesses
Leonardo, Michelangelo and the Renaissance 1400-1600:
thought the brain has ventricles to combine the senses, cognitition, memory. good artist but less understanding of the the brain. Giving life to Adam painting by Michelangelo may have actually been a Picture of the brain. Henry more: brain has no role in behaviour. Shakespeare: where is fancy bread in the heart or in the head
Descartes and dualism 1596-1650:
mechanical part of brain and another part with higher thinking (the mind and the brain). Mechanical: info to the pineal gland sends info to the mind then makes an action via nerves and fluid . Mental illness lost their link between the mind and the brain, children had undeveloped mind and animals had no mind. Jon jarqueo: mental illness caused by brain damage. West riding pauper lunatic asylum - bi lateral control
Relationship between structure and function
Thomas Willis 1600s-father of neuroscience had anatomically correct brain with cortex being memory, cc with thinking and imagination-localisation. Gall:phrenology 1800: feeling brain to tell personality. Flourens:quipotentiality challenged localisation as size of legion not located dictated deficits in pigeons. Karl lashley found size of legion on rags more important for mazes. Broca’s area=aphasia, saying language and wernciks for understanding, nick gage . Golgi first to get image, created stain, everything thanked. Cajal said nerve cells separated. Broadman:neurones organised diff in diff parts (cytoarchitectonics)
Techniques for brain activity
Single neurone recordings:stim in visual field and record AP (hubel and Wiesel but need electrode). Quiroga Jennifer Anniston effect. Electro/magneto encephalography-response of many neurones show localisation. Fmri and tms
Galvanni and mitsugoro
lightning struck metal attached to frog legs, made them move. His nephew got dead criminal bodies and sent electricity through them- deduced messages sent via electricity
Bando Mitsugoro 8th: wanted livers of puffer fish and died (rip) because it had toxin (VGC Na+ inhibitor)
Resting membrane potential
Neurone: cell body, nucleus, axon, dendron, dendrites, myelin sheath,nodes of ranvier, terminal buttons and synapse, lipid bilayer (has ion channel and na/k pump, specific/complementary to Na+ and K+).
Conc diffusion force e.g gradient and electrical force (+ and - attracted but equal each other out to -60mv): at rest, leak K+ are open
na/k pump: 3Na+ out 2K+ in, overall means inside is -, outside is + (polarised) and ATP hydrolysed, pump is phosphorylated
Action potential
Threshold value has to be reached (-50mv),triggers AP, Na+ vgc open, Na+ diffuses down gradient and down electric force, becomes depolarised (more+),. At +40mv ,na+ vgc close, K+ vgc open, K+ diffuses out (axon gets more -), more k+ leaves, becomes hyperpolarised to -75mv, K+ vgc closed, leak channels and pumps restore resting
APs only increase in freq not siz
History of the synapse
vagus nerve attached to heart in solution connected via tube to another heart. If vagus stim- causes HR to decrease, found that heart 2 also slowed. Means vagus nerve supplies chemical (NT)- led to development of drugs for MH disorders
Action of the synapse
Synapse is between the presynaptic membrane of the axon and the post of the dendrite. AP causes Ca2+ vgc to open and ca to diffuse in, binds to vesicles which causes them to bind to the presynaptic membrane and fuse w it. They release NT into the synapse which diffuse across and bind to NT receptors on post. Opens ion/Na vgc, Na diffuse in, creates an AP
Action of drugs on the synapse.
Drugs can be agonist-mimic NT as similar structure so bind to protein receptor or can be antagonist/ inhibitory as bind to protein receptor and blocks it
NT removal and summation
Removal: NT is taken up into pre or by degrading the NT via enzymes, if this doesn’t happen, NT can make the neurone toxic
Spatial summation: if two excitatory but if one excitatory and one inhibitory-no threshold reached (happens on the post)
Brain of a psychopath
Randy Kraft, serial killer used score card, on desth row pleading ngri, used pet scan. Raine did brain scans and found diffs between ngri and control: less pfc, parietal lobe activity , imbalance between 2 hemis, less occipital amygdala and hippo
Types of cells in neurones
Also have glial (gleele) cells: astrocyte (reuptake of NT, conveying blood to diff locations), oligodendrocyte (make myelin), microglial cells (immune responses)
CNS and PNS
cns is the brain and spinal cord, pns is all the nerves outside of these places, has the autonomic nervous system, made of para and sympathetic nervous system. Symp prepares for fight or flight, fright, fuck, para returns to resting state
-Grey matter is neurones, white matter is axons and myelin
Areas of the brain: lobes and general directions
Frontal (motor, body, decision making)-damaged in phinneas gage, parietal (sensorimotor), occipital lobes, temporal lobes (visual, hearing, language, emotion), named after bones
Superior and inferior, anterior (infront) and posterior, dorsal/ superior could be above, ventral/inferior could be below
Areas of the brain: folds and cortex
allows more SA, Gyrus: tops of the hills, sulcus: the valleys inbetween the hills, central sulcus separates frontal from parietal, precentral gyrus and post central gyrus either side. Sylvain fissure divides temp lobe from the frontal lobe and the parietal lobe
Cortex covers the brain made of grey matter
Areas of the brain: spec structures
Basal ganglia control movement and has internal capsule to send info, in middle above amygdala. Cc joins hemis. Thalamus deep in middle of brain, sensory processing. Hippocampus, hypothalamus does. Homeostasis, pineal gland produces melatonin, brain stem made of midbrain, pons and MO (unconscious actions), cerebellum does movement and coordination
Surface of the brain
Superior, middle and inferior frontal gyrus. superior, middle and inferior temporal gyrus, temporal pole at the front, below orbital gyri at front of frontal (where eyes are)superior parietal lobule
In occipital: supramarginal gyrus, angular gyrus and occipital gyri
Parietal occipital sulcus, below is the calcarine sulcus (visual), cingulate gyrus in middle, has cingulate suclus
General terminology and connections
take sections from: coronal/frontal divides anterior from posterior, sagittal divides the two hemis, horizontal divides superior from inferior. Association tracts are like motorways of axons within a hemi. Commissure is communication between hemis. Projection tracts cortical to subcortical, other areas of the CNS
Mininges and ventricles, also blood supply
Ventricles are involved in high level processing but do provide protection between the skull and the brain due to fluid (cerebral spinal fluid) kept in place by the meninges, disease of this is meningitis- bodies reaction is inflammation means nowhere for pressure to go only onto brain. Gets 20% of blood flow for only 2% of body weight, brain has two arteries (internal carotid and the basilar), join to make the circle of willis
Draw out the brain and label
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