Lecture 1

the fundamental unit

neurons

________ knew brain damage was correlated with behavioural impairments

physicians

aristotle thought that brains purpose was?

to cool the blood

reasons people didn’t know much about the brain

ack of neuroanotomi al data, religious views, philosophical views, no way to share information

when did early drawings happen, by who?

1543, by vesalius, many more came later like willis

arguments about functions of different brain regions

ventricles of fluid filled cavities were thought to be critical because full of CSF

________ proposed an influential fluid model

descartes

what was descartes model

fluid movements through the eye, nerves, and pineal gland play a role in controlling muscles

what kind of model was descartes

dualist, compatible with religion

what are distinctions in brain regions made with

visual, cytoarchitectural, functional, biological

cytoarchitectural distinctions

primary motor cortex has enormous Betz cells, requires microscopy

functional distinctions

requires neuroimaging and clinical studies

biological distinctions

gene expression profiles, requires advanced tools

visual distinction

based on landmarks like orbitofrontal cortex

holistic view

all brain regions in all functions, 1800s

localized function view

different regions have specific functions, early advocate was gall

some of gall’s arguments

based on observation that brain structure correlated with cognition in animals

experience dependent neuroplasticity

brain regions might change with use of their dedicated function

phrenology

19th century pseudoscience that assumed brain areas were related to mental traits, changes in areas would deform the cranium which led to the genuine husband vs unreliable husband images

fritsch and hitzig experiment

studied effects of brain stimulation on movement in dogs, found that zapping different parts of the brain resulted in different movements, showed some functional localization

strokes often result in brain damage and language impairment

aphasia

brocas aphasia

damage to broca’s area, results in speech fluency issues, hard slow laboured speech

wernickes aphasia

damage to wernickes area, results in speech comprehension issues, can speak properly but doesn’t make any sense, word salad

development of microscopy and advanced _______ _______ to reveal cells were critical events

staining methods like nissl stain to reveal neuronal structure and organization

ramon y cajal

father of modern neuroscience, advanced staining procedures used by golgi to visualize nervous system

neuron doctrine

nervous system made up of discrete individual cells

reticular theory

nervous system made up of a single continuous network

____________ proposed the synapse

sherrington

brodmann map

map based on cell structure and organization (cytoarchitecture)

52 regions, different functions

why use animals for research

ethical, reductionist/logical, evolutionary, comparative

ethical perspective

to infer behaviour causes relationships, we need experimental designs which directly manipulate the NS, unecthiclal to do this in humans

reductionist/logistic perspective

animals have a relatively simple ns and behaviours which are convenient to study

evolutionary perspective

ns similarities between species related to behavioural similarities

comparative perspective

differences related to differences

limitations of animal models

cost is high, modelling human behaviour is challenging, not all findings are generalizable

how do we study the neural mechanisms of depression in mice

have to translate the symptoms and feelings into them

inducing depression in mice

depression is connected to certain stressful events in humans, can expose mice to simile circumstances

chronic intermittent stress

models human stress with things that are meaningful to mice, for example water deprivation, cage tilting, strobe light, food deprivation, damp bedding

symptoms of depression in humans

loss of interest or pleasure in normally enjoyed activities

decreases energy

guilt and low self worth

disturbed sleep, appetite, activity

inability to concentrate

thoughts of suicide

anhedonia

absence of pleasure seeking behaviour

depression like behaviour in mice tests

tail suspension test, sucrose preference test, forced swim test

tail suspension test

how long do mice take to stop trying to get out of this unpleasurable position

sucrose preference test

putting something sweet which they like, see how long it takes for them to stop trying. anhedonia

forced swim test

how long does it take for them to stop trying to get out of water, stress coping indicator

key features of a disorder model

behavioural impairments similar to disorder, biological changes similar to disorder, behavioural impairments and/or biological changes are at least partially reversed by drugs which treat the disorder

prefrontal cortex

largest part of brain in front, not associated with motor function but everything else, particularly large in humans and chimpanzees