lecture 5: neurons and neurotransmitters Flashcards
whats the brains role in prediction and interpretation
it works out whats going on, whats going to happen in the future and how behaviour should change to best suit these situations
interpretation
smell = smells are purely a construction of the brain (good vs bad smells) , creating emotional experience of liking or disliking, the actual molecules aren’t good or bad
colours = dont exist out in the environment independent of us, its our nervous system which converts it into the sensation of being something
- our reality doesn’t necessarily correspond with everyone around us
predictions
your brain is continually making predictions about what is going to happen next
- past experience (memory) is most useful in guiding these processes
how much of the bodies energy does the brain demand
20%
central nervous system includes
brain and spinal cord
peripheral nervous system includes
peripheral nerves and ganglia
four lobes of the cerebral cortex
- frontal lobe = decision making, planning
- parietal lobe = working out where your body is in space and where limbs are relative to your body
- occipital = vision
- temporal lobe = memory
what separates the frontal lobe and parietal lobe
the central sulcus
what separates the front, parietal and temporal lobes
the sylvian fissure
cerebrum
perception of yourself as an individual being
cerebellum
learning skills eg: riding a bike
brain stem
controlling intake of food, water, basic behaviours you need to stay alive
grey matter
where all the critical cells and neurons are located
white matter
connects neurons to one another, or sends info down to control muscles
neurons
- the brains processing units (specialised nerve cells)
- approx 85,000,000,000 in the average human brain, each makes between 100-10,000 connections with others
what is the key to info processing in the nervous system
the inside of the neuron is negatively charged compared to the outside
- neurons have a membrane potential of about -70 mv
- info is transmitted within the cell by transient alterations in the membrane potential
dendrites
receive info from other neurons, called pre synaptic neurons, or from the environment
soma
the cell body of a neuron, containing the nucleus and vital organelles for maintaining the cells function and protein synthesis
axon
the long, slender projection of a neuron (nerve cell) that transmits electrical impulses away from the cell body to other neurons, muscles or glands
axon terminal
the specialised ending of an axon that transmits signals to other neurons or cells via neurotransmitters at synapses
resting membrane potential
the electrical potential difference across a cells plasma when the cell is at rest and not undergoing any significant electrical activity
graded potential
- pulse within a dendrite that can vary in size
- localised, temporary changes in a cells membrane potential that vary in magnitude according to the strength of the stimulus
action potentials
rapid, all or none, and long distance signals that can travel without weakening
ion channel
integral membrane proteins that contain pathways through which ions can flow
membrane depolarisation
the process where a cells membrane potential becomes less negative, often triggered by an influx of positively charged ions
temporal summation
the addition of multiple stimuli arriving at the same synapse in quick succession
spatial summation
the combined effect of multiple stimuli arriving at different locations on a neuron simultaneously
initial segment
actual site where the AP is generated
tetrodotoxin (TTX)
- 10,000 times deadlier than cyanide
- blocks ion flow through channels that generate action potentials
