Neuroscience Flashcards
neuroscience
study of the function & structures of the nervous system (brain, neurons, synapses, etc.)
behavioural neuroscience
relates to the observable actions of humans & animals (or artificial systems)
changes to our understanding of the brain are limited by. . .
- religious or moral views
- methodological limitations
- serendipity (reliance on chance discoveries)
- scientific conservatism
Hippocrates (Ancient Greece)
- considered father of modern medicine
- first to propose brain controls the body
- out brain is the command center of body (not heart)
- noted behavioural effects of brain damage
- observed anatomy through open wounds after traumatic head injury of soldiers & gladiators
Who formulated the mind-body problem?
- Rene Descartes, France
- was first to discuss interactions b/w mental & physical
- considered humans & animals like machines
- interested in involuntary reflexes & believed behaviour was driven
What about Luigi Galvani? (Italy) (frog man)
- first to suggest nerve signals are electrical (not fluid)
- rejected idea of animal spirits flowing through hollow nerves
- made a chance discovery that an electrical charge applied to a frog’s leg made the muscle contract
- suggested that nerves much be coated in fat to prevent electricity from leaking out
What about Franz Joseph Gall (Germany)?
- moving beyond mind & brain - first to propose idea of a modular brain
- was interested in relationship b/w brain & personality
- influenced by physiognomy
What is physiognomy?
art of ascribing personality characters to facial features
What did Franz Joseph Gall propose about the brain?
- proposed the brain is composed of several distinct “organs of thought” or faculties
- reflected by characteristic patterns of bumps on skull
- skull maps used to read person’s character
- this is known as PHRENOLOGY
What did Franz Joseph Gall (Germany) introduce?
the important notion of “cortical localisation of function”
- modular organisation
Who provided the first solid evidence of brain modularity?
Paul Broca (France)
- first described in patient Leborgne
- unable to speak after damage to left frontal lobe
- normal chewing & language comprehension
Broca’s aphasia
- autopsy used to figure it out
Carl Wernicke, Germany
-Wernicke’s area
- Unable to comprehend speech
- Normal hearing & language production
- Similar patients subsequently seen with
damage to posterior part of the superior gyrus
How much does adult brain weigh?
1400 g - it is 3% of body weight
How many neurons in adult brain?
100 billion neurons
1,000,000 billion synapses
10^1000000 possible circuits
How much of the energy resources of body does the brain consume?
20%
Is also remarkably energy
efficient running on
20Watts (equivalent to
simple light globe)
Neuropsychology is. . . ?
- Research and clinical speciality
- links brain damage (lesions) with psychological
processes - assess risk (before surgery),
- assess impairments and improvements (after
damage) - behavioural and neuroimaging measures
What is psychopharmacology?
looks at - the role of neurochemistry in mind and behaviour
- natural = neurotransmitters & Hormones
- artificial = drugs
more neurons in the brain =
more synaptic connections = more complexity of brain
The Allen Brain Institute
- 100 million donation from Microsoft founder Paul Allen
- Creating very detailed maps/atlas with data from mouse & human brain from brain areas > neurons>genes
The Human Brain Project
- EU 10-year initiative worth over $1 Billion
- emphasis on simulating neurons for brain inspired computing, neuromorphic computing
What does the human brain project state?
- HBP seeks to bring the bring vital software tools to neuroscience to:
- reduce the need for animal experiments
- study diseases in unprecedented in silico experiments
- improve the validation of data and experiments with computational validation
What does the virtual brain do?
Simulates/models whole brain dynamics and
functional connectivity to understand global brain function in healthy and disordered states like epilepsy
Main 2 divisions of nervous system
peripheral nervous system (PNS)
central nervous system (CNS)
PNS
cranial & spinal nerves
CNS
- brain (including retinal cells in eyeball) & spinal cord
- brain is encased by skull
- spinal cord sits in vertebrae
- allows both protection & flexibility in a moving body
PNS
- refers to network of nerves that extend out from CNS throughout body
- sends messages from brain to control muscle movement
- receives sensory info about body position, pain, temperature, & transmits to CNS
2 main systems in PNS
- somatic & autonomic
Somatic system
- subdivision of PNS
- connects to CNS to sensory input & voluntary motor output
- controls movement of skeletal muscle
- efferent & afferent cranial nerves
- also includes spinal nerves (sensory & motor pathways) that extend through vertebrae
Autonomic system
- connects central system to non-voluntary muscles & glands
- smooth muscle, cardiac muscle
- consists of PARASYMPATHETIC & SYMAPTHETIC system that regulate important bodily functions & responses through opposing influences throughout body
- also includes enteric nervous system which supports digestion
Somatic nerve fibers
efferent nerve fibers send signals from brain to muscle
afferent nerve fibers send signals from peripheral sensory areas to communicate from sense modalities back to brain
sympathetic nervous system
driven predominantly by increased noradrenaline (NA) & adrenaline
parasympathetic nervous system
driven mainly by Ach release (acetylcholine)
REST & DIGEST
Enteric nervous system
- ENS is part of peripheral nervous system
- contains 100 M neurons
- has its own reflexes & senses & can act independently of the brain
- nearly every neurotransmitter found in brain is also found in gut
- plays a major role in emotions & stress
- helps digestion
Enteric nervous system
- ENS is part of peripheral nervous system
- contains 100 M neurons
- has its own reflexes & senses & can act independently of the brain
- nearly every neurotransmitter found in brain is also found in gut
- plays a major role in emotions & stress
- helps digestion
