Claustrum Flashcards
What does claustrum mean?
hidden away or “to close or shut”
Where is the claustrum?
between striatum/putamen and insula
Compared to the cerebral cortex what percentage of cells does the claustrum have?
claustrum has <1% of the cells of the cerebral cortex
Why is it difficult to stimulate the claustrum?
- it is hidden by surrounding axon white matter tracts
- trying to stimulate claustrum is DIFFICULT WITHOUT STIMULATING THE SURROUNDING AXONS
What kind of imaging can be usd to detect claustrum connections with the cortex?
diffusion tensor imaging
As a function of its volume, what brain structure is the most densely connected region?
claustrum
which parts of the brain are the claustrum axons mostly connected to?
- most FRONTAL parts of cerebral cortex
- most POSTERIOR parts of the cerebral cortex
Which part of the brain does the cluastrum have the strongest BIDIRECTIONAL communication with?
frontal cortex
TRUE or FALSE: there is generally a strong sensory cortex input to the claustrum
FALSE: weak sensory input
Which NT (cells) project to the claustrum?
- serotonin
- dopamine
- ACh
Which part of the frontal cortex has the strongest bidirectional connection with the claustrum?
limbic and associative
List the following inputs to the claustrum from most ventral to dorsal:
- olfactory
- visual
- sensory motor
- PFC
- auditory
olfactory > PFC > sensory-motor > auditory > visual
TRUE or FALSE: claustrum outputs are predominantly glutamatergic, so they hyperpolarize neurons
FALSE: yes glutamatergic, but that means they depolarize cells
TRUE or FALSE: frontal cortex receive input from ventral claustrum, and posterior cortex receive input from dorsal claustrum
FALSE:
- FRONTAL cortex receive input from DORSAL claustrum
- POSTERIOR cortex receive input from VENTRAL claustrum
TRUE or FALSE: the anatomical organization of claustrum-cortex connections is the same across species
FALSE: these connections are different across species
TRUE or FALSE:
- in humans and primates, the claustrum has pronounced connections with the pre-motor areas of the frontal cortex
- in rodents and cats, the claustrum has pronounced connections with the visual cortex
FALSE:
- in humans, primates, and CATS, claustrum –> VISUAL CORTEX
- in rodents, claustrum –> pre-motor areas
TRUE or FALSE:
- in humans, primates, and cats, the claustrum plays a large role in vision
- in rodents, the claustrum plays a large role in motor control
TRUE
What are the 2 subtypes of excitatory cells?
- type 1 (non spiny)
- type 2 (spiny)
What is the difference between type 1 and 2 excitatory cells?
- type 1: non spiny; low dendritic spines; NO AP bursts
- type 2: spiny; extensive dendrites; AP bursts
How do claustrum neurons respond to cortical inputs?
feedforward inhibition
Are claustrum inputs to PV cells or ClaC cells stronger?
inputs to PV cells stronger
What is the best way to activate the claustrum?
optogenetics
how does ChR2 allow depolarization in response to blue light?
increase inward sodium currents
TRUE or FALSE: because claustrum outputs are glutamatergic, activation of the claustrum excites excitatory cells in the PFC.
FALSE: it is glutamatergic, but it activates INTERNEURONS that INHIBIT excitatory cells in the PFC
TRUE or FALSE: activation of the claustrum causes inhibition of INs and activation of pyramidal cells
FALSE:
- inhibition of pyramidal cells
- excitation of INs
Which type of INs allow the claustrum to generate cortical inhibition?
NPY interneurons
What happens to pyramidal cell firing when NPY neurons are suppressed?
increase in firing
TRUE or FALSE: the claustrum excites both the PFC and the RSP (posterior cortex)
FALSE:
- inhibit PFC
- excite posterior regions
What does RSP stand for and where is it in the brain? Is it excited or inhibited by the claustrum?
- retrosplenial cortex
- located at posterior regions of the cortex
- excited by the claustrum
How does the frontal cortex modulate the posterior cortex?
connected by the claustrum
TRUE or FALSE: activation of the LEFT frontal anterior cingulate cortex activate claustrum neurons projecting to the RIGHT visual cortex
TRUE
what kind of waves does the claustrum-stimulate waves look like?
slow wave sleep
Are claustrum cells more active during sleep or during awak?
during sleep
What kind of memories are thought to be consolidated or stabilized during sleep?
episodic
Since claustrum cells are active during slow wave sleep, what does this imply.
It may also play a role in memory consolidation, which happens during slow wave sleep
In associative learning, when do claustrum cells start to increase their firing?
during the CS (e.g. during the tone presented before the puff of air)
TRUE or FALSE: lesioning the claustrum increased learning of the CS-CR response
FALSE: decreased learning
TRUE or FALSE: if the claustrum is inhibited, mother mice are much quicker to retrieve their pups
EXPLAIN.
FALSE: if claustrum inhibited, mother mice take MUCH LONGER to retrieve their pups
this is because the claustrum is involved in “ignoring” sensory stimuli that are not deemed important for the task
What kind of opioid receptors are mainly found on claustrum cells?
kappa opioid receptors
which drug activates kappa opioid receptors? What is the active compound?
- salvia
- salvinorin A (active)
Does salvia binding to kappa opioid receptors cause presynaptic inhibition or excitation of release of NTs?
inhibition
What are the symptoms or taking salvia?
intense hallucinations; delirium; sleep-like state; detachment from reality
Is salvia a kappa opioid agonist or antagonist?
agonist
Does salvia enhance or inhibit release of NTs?
inihibit
Which NT does salvia affect? How does it affect its release?
REDUCES release of GLUTAMATE
Besides kappa opioid recrptors, which other receptor is largely found in the claustrum?
serotonergic 5HT2A receptors
Which drug can activate 5HT2A receptors?
psilocybin
What are the symptoms of taking psilocybin?
hallucination, euphoria, changes in perception
What is the effect of psilocybin the PFC?
increase spine density
TRUE or FALSE: psilocybin effects are long-lasting
TRUE
Does psilocybin increase or decrease claustrum activity?
decrease claustrum activity (increase PFC activity b/c claustrum inhibits PFC)
