- The interaction of the mammalian brain and immune system is:
|only a defensive response to pathogens|
|always a destructive autoinflammatory pathology|
|sometimes a normal part of development|
|always either a response to a pathogen or a destructive autoinflammatory pathology|
- The brain is surrounded and protected by the blood-brain barrier (BBB), a border of endothelial cells which separates the blood from the fluid surrounding the central nervous system. Testosterone is produced in the gonads, so how can it affect development of the brain?
|Testosterone cannot cross the blood-brain barrier and must direct cells lining the BBB to secrete their own signaling molecules to influence the brain.|
|Steroid hormones are relatively small and lipophilic, so testosterone readily crosses the selectively permeable blood-brain barrier and acts directly on androgen receptors (or is locally converted into estradiol and acts on estrogen receptors)|
|The blood-brain barrier only prevents the migration of cells; anything soluble in the blood fluid can easily cross it.|
|Testosterone does not do anything to the brain.|
- Increased microglial phagocytosis in response to endocannabinoid (eCB) signaling was observed:
|throughout all regions of the brain|
|only in the amygdala|
|throughout the entire body|
|the prefrontal cortex|
- For what purpose did the authors use an antibody against ionized calcium binding adaptor molecule 1 (Iba1)?
How did they determine which cells were engaged in phagocytosis?
- Staining for proliferating cell nuclear antigen (PCNA) enabled the authors to determine the cells the microglia were engulfing were recently divided cells. Since microglia are known to phagocytose dead or apoptotic (dying) cells, the researchers looked for a specific marker of apoptosis.
What was it?
Based on this experiment, were the microglia engulfing apoptotic cells, or otherwise viable cells?
- The presence of DAPI in a phagoyctic cup is taken to mean that:
|the microglia are engulfing debris|
|the microglia are engulfing cells (DAPI stains the nucleus, specifically DNA)|
|the microglia are undergoing apoptosis|
|the microglia are impermeable|
- The phagocytic activity of microglia could be intrinsic to the sex (XX vs XY chromosomes). How do the authors investigate this? What result do they find?
- What question did the authors attempt to address using the thymidine analog 5-bromo-2′-deoxyuridine (BrdU)? What was the finding?
- What molecule did the authors use to prevent phagocytosis? What question were they addressing? What was the outcome of this experiment?
- What are some putative or known roles of the anterodorsal (MeAD), anteroventral (MeAV), posterodorsal (MePD), and posteroventral (MePV) regions of the amygdala (this may not be in the paper)?