Neuroscience Flashcards
Central Nervous System
- Brain and spinal cord
- Contains 86 billion neurons
- We can only use 10% of our brain is a myth
Peripheral Nervous System
- Stuff other than brain and spinal cord
Peripheral Nervous System: SENSORY NERVOUS SYSTEM
- Nerves picks up information –> Sends to spinal cord –> Sends to brain
Peripheral Nervous System: MOTOR NERVOUS SYSTEM
- Signals coming from brain –> Sends to muscles –> Muscles contract –> Movement
Autonomic Nervous System
- Controls important bodily function that we don’t need to think about
- Uses neurotransmitters
E.G. Heart rate
Sympathetic Nervous System
- Engages body for fight or flight
- Increases blood pressure
Parasympathetic Nervous System
- Resting conditions
- Decrease blood pressure
Enteric Nervous System
- Controls digestive activity
- Senses physical and chemical conditions in gut
CNS Protection
- Bone
- Meninges - Protect brain from hitting skull
- Blood-Brain Barrier
Brainstem
- Regulates life-supporting functions (Maintain breathing)
- Regulate basic aspects of movement (Posture)
Cerebellum
- Controls precise movements outside our consciousness
- Occupies 10% of brain but contains 70% of neurons
- E.G. Quickly controls the placement of hand when catching ball
- E.G. Controls balance when stepping on escalator
Thalamus
- Sensory relay to cortex
Hypothalamus
- Hormonal regulation
- Motivational control
Limbic System
- Control emotion and memory
- Smell is evocative sent to limbic system straight away
Basal Ganglia
- Control thoughts and actions
- Cerebellum is fine tuning motor neurons to make precise movement
- Basal Ganglia decides which movement should be done now
Neocortex
- 1cm thick tissue wrapped around brain
Corpus Callosum
- Connects 2 hemispheres
Lobes of Neocortex
- Frontal Lobe - Future planning
- Parietal Lobe - Spatial awareness
- Temporal Lobe - Memory and language
- Occipital Lobe - Vision and recognising different objects
Sleep Depravity
- Affects acquiring and remembering information
- Contributes to overeating
- Increases sympathetic nervous system
What Keeps Us Awake?
- Pons, locus coeruleus and raphe nuclei maintains our arousal by sending axons to forebrains
- Locus coeruleus releases noradrenaline
- Raphe nuclei releases serotonin
- Pons release acetylcholine
What Sends Us To Sleep?
- Preoptic area is responsible for making us tired
- Destruction of this area can cause insomnia
Adenosine
- While we are awake, adenosine is built up
- Adenosine increases sleepiness by inhibiting alertness
- Caffeine blocks adenosine receptors and prevents adenosine from binding
Melatonin
- Increases in the evening and peaks during midnight
- Has a clock mechanism that rises in evening and decrease during day
- When jet lagged melatonin is high when new country is during daytime
Sleep Cycles
- When we’re awake, the electrical activity in our brains is high frequency
- When we’re tired or sleeping the activity becomes slower and wave form is larger
REM Sleep
- Neurons in pons wakes up during REM and projects to back of thalamus which projects to visual cortex
- During REM, limbic system becomes active because when we are dreaming we are emotional
- During REM, we believe all our dreams are real because the prefrontal cortex which is usually” nah this can’t be true”, is suppressed
Neural Mechanism of Reward
- If you stimulate the medial forebrain bundle it produced a powerful reward
- Rat pressed lever over and over again and would receive electrical simulation in medial forebrain bundle
- It prefer to starve or even tolerate shocks in order to continue self stimulating
Right Hemisphere
- Receives sensory input from left and controls motor response on left side of body
Left Hemisphere
- Receives sensory input from right and controls motor response on right side of body
Lateralisation of Language
- Biased 90% right handed and 10% left handed due to language being lateralised in our left hemisphere
Dichotic LIstening Task
- If person is hearing a different voice in each ear saying something, they will understand a word faster if presented to right ear since the right ear travels to left hemisphere straight away
- If words presented to left ear, it travels to right hemisphere and travels through corpus callosum and then to left ear
Damage to Borca’s Area
- People can only utter words
- Can’t produce fluid speech
- Problems with writing but not drawing
- E.G. People saying words, but it is stopping and not fluid
Damage to Wernicke’s Area
- Difficulty understanding language and speech
- Can produce fluid speech
- E.G. People saying words, it’s fluid but it’s not making any sense
Split Brain (Roger Perry)
- If object was placed in right hand, it was going to left hemisphere so can tell what the object was
- Of object was placed in left hand, it was going to right hemisphere and can’t travel to left due to corpus callosum was cut
HM
- Hippocampus removed
- Memories were intact but couldn’t learn new information
Alzheimer’s Disease
- Loss of newly learned information
- Widespread degeneration of brain tissue
Brain Lesions
Transcranial Magnetic Stimulation (TMS)
- Uses magnetic pulses to stimulate parts of the brain and study their functions
Single-Cell Recording
- Observing the activity of individual brain cells
Functional Imaging
- Techniques for observing which areas of the brain are active
- EEG
- MRI
- fMRI
- MEG
EEG
- Records electrical activity in the brain
- Good for timing (temporal resolution)
- Not good in locating where activity happens
MRI
- Shows detailed images of brain structures by measuring water in brain tissues
fMRI
- Shows which brain areas are active by measuring oxygen levels in blood
- Good spatial resolution
- HOWEVER, response is a bit delayed
MEG
- Measures magnetic fields from brain activity
- Good spatial and temporal resolution
- HOWEVER, expensive and sensitive to interference
Lateral Hypothalamus
- Controls hunger
- Damage makes animals eat less
Ventromedial Hypothalamus
- Controls fullness
- Damage causes animals to eat more frequently but in normal meal sizes
Arcuate Nucleus
- Contains neurons that either promote or suppress eating
- Reacts to hunger and fullness signals from hormones