Lecture 34 Flashcards
Hindbrain
medulla
pons, cerebellum
Midbrain
substantia nigra
Forebrain
cerebral cortex
basal ganglia: striatum, globus pallidus, subthalamic nucleus
limbic system: hippocampus, amygdala
diencephalon: thalamus, hypothalamus
Medulla
autonomic functions: control of involuntary movements
controls respiration, cardiac function, vasomotor responses, reflexes
Pons
key of neurotransmitters
relays signals from the forebrains to the cerebellum
Cerebellum
little brain
governs motor coordination for producing smooth movements
undergoes neurodegeneration in spinocerebellar ataxias
Substantia nigra
SN pars compacta: produces dopamine
provides input to the basal ganglia, supplies dopamine to the striatum
involved in voluntary motor control and some cognitive functions
undergoes neurodegeneration in PD
Cortex
involved in processing and interpreting information
Damage can affect movement, speech, personality
Damage to the frontal cortex can lead to schizophrenia
Basal ganglia
striatum, globus pallidus, subthalamic nucleus
Limbic system
emotions (amygdala), memory (hippocampus)
Where are decisions made?
cortico-thalamic loops about how to interpret and act on the incoming sensory information
What can damage to the cortex do?
affect movement, speech, personality
Where does schizophrenia occur?
disease of frontal cortex
Astrocytes
provide neurons with growth factor, antioxidants
remove excess glutamate (excitotoxic neurotransmitter)
support the BBB
Oligodendrocytes
produce myelin sheath that insulates axons
Microglia
provide growth factors
clear debris by phagocytosis
role in neuroinflammation
overactive in alzheimer’s
BBB
The BBB is stabilized by tight junctions in the endothelial cell layer of blood vessels in the brain
NEURON
?
Normal action potential
slide 13
lasts 0.2-0.5 msec
refractory period: period after action potential during which a neiron will not fire again
Excitatory neurotransmitters
slide 15
Inhibitory neurotransmitters
slide 16
Drugs can alter synaptic transmission by various mechanisms
figure on slide 20 and 21
Common amino acid neurotransmitters
GABA
Glycine
Glutamate
GABA
major inhibitory neurotransmitter in the brain
depresses neuronal excitability by increasing the influx of Cl- ions into the neuron: making more negative
there are GABA-A and GABA-B receptors
drugs that interact with GABA pathways are CNS depressants such as: sedative hypnotics, anticonvulsants, anxiolytics
disorders: seizures, spasticity, addiction/alochol
Glycine
similar to GABA but acts in the spinal cord
Glutamate
major excitatory aa neurotransmitter in the brain
excess glutamate can cause neuronal damage by allowing excessive Ca influx into the neuron
Common non-amino acid neurotransmitters
acetylcholine
dopamine
norepinephrine
serotonin; 5-hydroxytryptamine (5-HT)
