CNS Flashcards
What makes up the hindbrain?
-medulla
-pons
-cerebellum
What makes up the midbrain?
-substantia nigra (SN)
What makes up the forebrain?
-cerebral cortex
-basal ganglia: striatum (caudate & putamen), globus pallidus, sub-thalamic nucleus
-limbic system: hippocampus, anygdala
-dienecephalon: thalamus, hypothalamus
What are the parts of substantia nigra?
-SN pars compacta
-SN pars reticulata
What role does the SN pars compacta play?
-provides input to the basal ganglia, supplies dopamine to the striatum
*undergoes neurodegeneration in PD
What role does the SN pars reticulata play?
-has an output function, relays signals from the basal ganglia to the thalamus
What does the cerebellum do?
-hindbrain
-“little brain”
-governs motor coordination for producing smooth movements
*undergoes neurodegeneration in spinocerebellar ataxias
What does the medulla do?
-hindbrain
-“autonomic functions”
-includes centers for controlling respiration, cardiac function, vasomotor responses, reflexes (coughing)
What does the pons do?
-hindbrain
-“bridge”
-relays signals from the forebrain to the cerebellum
What does the cortex (cerebrum) do?
-forebrain
-processing and interpreting information
-“high-order processes”
-Schizophrenia is considered a disease of the frontal cortex
What does the limbic system do?
-forebrain
-emotions (amygdala)
-memory (hippocampus)
What does the hypothalamus do?
-regulates internal homeostasis, emotions
-hormonal control (through the pituitary gland) and direct neural regulation
-involuntary functions
What does the thalamus do?
-‘relay station’ to and from the cortex
What does the basal ganglia do?
-voluntary motor control, some cognitive functions
What do astrocytes do?
-provides neurons with growth factors, antioxidants
-supports blood-brain barrier
-removes excess glutamate
What do oligodendrocytes do?
-produces myelin sheath
What do microglia do?
-provides growth factors
-clears debris via phagocytosis
-plays a role in neuroinflammation (if overactive)
What is an EPSP?
EPSP- excitatory postsynaptic potential–> subthreshold depolarization peak
What are the various mechanisms that alter synaptic transmission?
Metabolism- can inhibit enzymes that breakdown neurotransmitters
Uptake- transporters can be blocked to prevent uptake into either the neuron or glial cell
Receptor- can have agonist or antagonist effects that targets the natural neurotransmitter
Degradation- enzymes can inhibit/promote degradation
What are the common amino acid neurotransmitters?
Glutamate
Glycine
GABA
What can excess glutamate do to a neuron?
-cause neuronal damage by allowing excessive Ca2 influx into the neuron
What is glycine similar to?
-GABA but works in the spinal cord
What does GABA do?
-major inhibitory neurotransmitter in the brain
GABA A ion channel allows for influx of Cl- ion
What does Glutamate do?
-offsets GABA
-major excitatory neurotransmitter in the brain
-can be metabotropic (GPCRs) or ionotropic (AMPAs or NMDAs)
What are the common non-amino acid neurotransmitters?
Serotonin
Dopamine
Acetylcholine
Norepinephrine
What type of drugs target Acetylcholine?
-cholinesterase inhibitors such as Aricept used to treat Alzheimer’s disease
What type of drugs target Dopamine?
-drugs that block DAT increasing intracellular dopamine (amphetamine and cocaine)
-antipsychotics (D2 receptor antagonists)
-D2/D3 & D1 receptor agonists for Parkinson’s Disease
-excess dopaminergic signaling may be involved in Schizophrenia
What type of drugs target Norepinephrine?
-NET inhibitors are used to treat depression
What type of drugs target Serotonin?
5-HT2A Antagonists as atypical antipsychotics; can be useful for schizophrenia treatment
5-HT1D agonists for migraine
5-HT2A agonists are hallucinogenic (LSD)
SERT uptake inhibitors for depression
*5-HT axons arise from cell bodies call raphe nuclei
