Pathophysiology of CNS - Rochet Flashcards
What structures are found in the hindbrain?
Medulla
Pons
Cerebellum
What structures are found in the midbrain?
Substantia nigra
What structures are found in the forebrain?
Cerebral cortex
Basal ganglia
Limbic System
Diencephalon
What structures are found in the basal ganglia?
Striatum
Globus pallidus
subthalamic nucleus
What structure are part of the limbic system?
Hipocampus
Amygdala
What structures are part of the diencephalon?
Thalamus
Hypothalamus
What does the medulla do?
- Respiration, cardiac function, vasomotor responses, reflexes
- Reticular system (arousal, wakefulness)
What does the pons do?
Relays signals from forebrain to cerebellum
What does the cerebellum do?
-Motor coordination (smooth movements)
What structures are part of the brain stem?
Medulla
Pons
What does the cerebellum look like?
A little brain (two lobes)
What is a sagittal section?
Cut between the eyes
What are the substantia nigra (SN) pars compacta do?
- INPUT to the basal ganglia
- Voluntary motor control, some cognitivie functions
- Neurodegeneration in PD
The SN pars compacta provides input to the basal ganglia by supplying _______ to the _____
dopamine to the striatum
What does the SN pars reticulata do?
OUTPUT: signals from basal ganglia to the thalamus
What does the cortex do?
Process and interpret info
What does the basal ganglia do?
Voluntary motor control
Cognitive functions
What does the amygdala do?
Emotions
What does the hippocampus do?
Memory
What does the thalamus do?
Relay station–to and from the cortex
What does the hypothalamus do?
Regulate homeostasis
Emotions
Hormonal control
Neural regulation
Where is the amygdala located?
The base of the hippocampus
Decisions are made in _____ loops about how to act on information
cortico-thalamic loops
Schizophrenia is a disease of the _____
frontal cortex
Efferent/afferent neuron tracts transmit signals from the cortex to the periphery?
Efferent
Efferent/afferent neuron tracts transmit signals from the periphery to the cortex?
Afferent
What is the hierarchy of information processing in CNS?
Spinal cord –> hindbrain/cerebellum –> midbrain –> forebrain
The brain is surrounded by layers of membrane called _____
Meninges
What are the three meninges layers?
Dura
Pia
Arachnoid
What is the outer layer of the meninges?
Dura
What is the middle layer of the meninges?
Arachnoid
What is the inner layer of the meninges?
Pia
What fills the space in b/w arachnoid and pia?
CSF
Which layer of the meninges contains blood vessels?
Arachnoid
What is a tumor of the meninges called?
Meningeoma
What is the artery that enters the brain called?
Internal carotid artery
What 4 arteries does the internal carotid artery branch into?
Anterior Cerebral
Middle Cerebral
Posterior communicating
Opthalmic
Migraine involves _____ of cerebral arteries
Dilation
What are the glial cell types?
Astrocytes
Oligodendrocytes
Microglia
What do astrocytes do?
- Provide growth factors and antioxidants
- Remove glutamate
- Support BBB
What do oligodendrocytes do?
Produce myelin sheath
What do microglia do?
Provide growth factors
Clear debris (phagocytosis)
Neuroinflammation (play a role)
What percent of brain cells are glial cells?
80%
Which of the glial cell types is responsible for neurinflammation?
Microglia
Which of the glial cells provide growth factors?
Microglia and astrocytes
Endothelial cells in the BBB are connected by ____
tight junctions
What properties of molecules can get through the BBB?
Non-polar
<500 Daltons
A resting cell is positive/negative inside?
negative
What is a cell body called?
Soma
What are nodes of ranvier?
Gaps in myelin sheath where the AP can be re-initiated
Normal resting potential is about ___?
-80 mV
How long does an AP last?
0.2-0.5ms
Larger diameters have faster/slower rates?
Faster
T/F: Action potentials for a single neuron always have the same magnitutde
True
The current in a nerve fiber is greater as a result of ____
summation
What is a nerve fiber?
Bundle of axons
What are EPSPs?
Excitatory post-synaptic potential
Excitatory neurotransmitters act on __- receptors and allow ____ to cross the membrane
ionotropic
Na+ ions
An increase in strength of stimulus will increase _____ but not _____
magnitude of depolarization but not magnitude of action potential
Does an EPSP always trigger an AP?
no– can bring cell closer to threshold so the next EPSP causes AP
Whta are IPSPs?
inhibitory post-synaptic potentials
Inhibitory neurotransmitters induce ____ by allowing ___ to cross membrane
Hyperpolarization
Cl-
Usually drugs in the CNS modify ____
synaptic neurotransmission
What are common aa neurotransmitters?
GABA
Glutamate
Glycine
Is GABA excitatory or inhibitory?
Inhibitory
GABA caues influx of ___
Cl-
What are the 2 GABA receptors?
A and B
What drug classes interact with GABA pathways?
Sedative hypnotics (benzodiazepines, barbiturates)
anticonvulsants
Anxiolytics
Which of the GABA receptors is inotropic and which is GPCR?
A - inotropic
B - GPCR
Is glutamate inhibitory or excitatory?
Excitatory
Glutamate causes ___ to enter cell?
Calcium
What disease are caused by GABA?
Epilepsy
Spasticity
addiction/alcohol
What is glycine?
NT similar to GABA–but in spinal cord
What does excess glutamate cause?
Damage to neuron
What disease does excess glutamate cause?
Epilepsy
Schizophrenia
What are the metabotropic glutamate receptors?
GPCRs - mGluR
What are the ionotropic glutamate receptors?
NMDA, AMPA (ion channels)
What are the non-amino acid NTs?
Acetylcholine
Dopamine
Norepinephrine
Serotonin (5-HT)
Acetylcholine receptors are ___ and ___?
Muscarinic, nicotinic
Where is acetylcholine found?
Basal forebrain, pons, cortex, basal ganglia
What does acetylcholine cause?
Cognitive function/decline
Nicotine dependence
Movement disorders
Is acetylcholine excitatory or inhibitory?
Excitatory
Where does glutamate work?
All over the brain
Where does GABA work?
All over the brain
What disease does dopamine contribute to?
Schizophrenia Parkinson's disease Depression Addiction ADHD
Where is dopamine found?
Midbrain (SN, VTA)
Dopamine neurons arise from __ and ____
Ventral tegmental area, SN
Blocking DAT causes what?
Increased dopamine (no reuptake) which causes addiction/euphoria
PD is caused by ___ of DA
loss
Schizophrenia is caused by ___ dopamine
excessive
What drugs interact with DA pathways?
Antipsychotics (D2 antagonists)
D2/D2, and D1 agonists (for PD)
What type of receptors are all dopamine receptors?
GPCR
Norepinephrine targets what receptors?
alpha and Beta adrenergic
What is NET?
Norepinephrine transporter (drug target)
Where does norepinephrine work in the brain?
Pons
What diseases is NE involved with?
Memory
Depression
Addiction
Pain
NET inhibitors are used to treat___
depression
Serotinin is involved with what disease?
Depression
Mood disorders/anxiety
Schizophrenia
What are drug targets for serotoinin?
Receptors and serotonin transporter (SERT)
Which of the serotonin receptors is NOT GPCR? What is it?
5-HT3 - ion channel
Where does serotonin work?
Midbrain/pons
5-HT axons arise from a group of cell bodies in the brain stem called the ______
raphe nuclei
Serotonin systems are involved in what 4 normal things?
- Sleep
- Vigilance
- Mood
- Sexual function
SERT inhibitors are used to treat what?
Depression
5-HT2A agonists are ___
Hallucinogenic
5-HT2A antagonists are used as _____
atypical antipsychotics
______ is used to treat migraine
5-HT1D agonists