Lec 2: Neurons, Neurotransmission, and the CNS Flashcards
glial cells
- “glue” of the nervous system
- help bind together the brain to perform its tasks
astrocyte
- type of glial cell
- help create blood-brain barrier
neurodevelopment: early versions help create “scaffold” to help build the brain
response to injury: release chemicals after an injury that are thought to facilitate the stopping of the injury and stabilize neurological functioning
microglial cells
- type of glial cell
- “scavengers” of the nervous system
- eat dead and dying neurons
oligodendrocyte
- type of glial cell
- support neurotransmission
- insulate the axon to help ensure signal reaches the end
- only found in brain and spinal cord
schwann cell
- type of glial cell
- insulate axons outside of the brain and spinal cord
3 classes of neurons
- motor: carry info about how part of you body should move
- sensory
- interneurons:
- majority of our neurons
- process variety of info
- processing unit of the brain
Multiple sclerosis (MS)
- myelin degrades, which causes damage in the axon
- as the disease progresses, more neurons become compromised
- compromises ability of neural systems to send signals
- immune system attacks the myelin
- variability in symptoms, depends on where the myelin is degrading
Amyotrophic lateral sclerosis (ALS)
- kills motor nerve cell, causes muscles to weaken
- rapidly progressing upper and lower motor disease that results in death
- at first person starts to become uncharacteristically clumsy
- difficulty with coordination and walking
- in advanced stages, impairs ability to control breathing and other vital functions
ischemia
- arteries build up plaque and get clogged
- blood supply to the brain is stopped
- neurons need oxygen to control ion fluxes
- deprived oxygen stops the generation of A.P.s
- neurons enter electrical failure
- prolonged oxygen can lead to neuron death
dopamine
Site of production:
- substantia nigra
- ventral tegmental area (VTA)
Links to cognition:
- higher order cognition
- voluntary movement
- reward/reinforcement learning
Dysfunction:
- Parkinson’s disease
- psychotic thoughts/behaviour
- addiction
Norepinephrine
Site of production: locus coeruleus
Links to cognition:
- cognitive arousal/attention
- memory and mental flexibility
- mood
Dysfunction:
- Alzheimer’s disease (low levels)
- mood disorders
- visuospatial neglect
serotonin
Site of production: raphe nucelus
Link to cognition: mood
Dysfunction:
- mood disorders
- psychotic thoughts/behaviour
Acetylcholine
Site of production: basal forebrain
Links to cognition:
- sensory processing/attention
- learning and short-term memory
- movement
Dysfunction
- Alzheimer’s disease
- Myasthenia gravis (PNS)
Challenge of Psychopharmacology
- an individual’s baseline level of a neurotransmitter can wary
- neurochemical levels can be affected by lots of diff factors
- Yekes-Dodson Curve and the optimal amount of a given neurotransmitter (too much or too little of a neurotransmitter can cause a deficit in performance)
Corticospinal tract
- very important for voluntary motor control
- signal begins in motor cortex and goes to midbrain then medulla
- crosses to the other side of the body via the medullary pyramids then goes to spinal cord
medial lemniscal tract
- major ascending somatosensory tract
- transmits touch info to the brain
- tells the brain how the body is arranged in space
- tells if muscle is extended or relaxed
- helps understand body orientation even if you can’t see it
lateral spinothalamic tract
- major ascending somatosensory tract
- transmits pain and temperature information to the braina
