theca cells

Breakdown of Baymax’s neurological scan of Hiro in Big Hero Six

Getting the chance to see Big Hero Six for a second time, on my computer, allowed me to pause the screen and check out all the cool details more carefully.  I was especially interested in the scene where Baymax is scanning Hiro’s neurological functioning.  I wanted to see if the writers and animators just phoned this bit in with a bunch of made-up jargon and figures, or if they actually did their research to add an extra level of authenticity.  I was happy to find that it was the later of these two options.  Even more so than I had hoped for.  They didn’t just do the research, they clearly got a real neurologist to consult on this…  It’s a super impressive facsimile of what a real, super high-tech neuro-scan would look like, right down to being gender and age-specific.

Check it out:

On the viewer’s left side of the screen, just below ‘diagnosis’ there is a list of symptoms.  After ‘no physical injury’ it reads ‘GPR54 detected.’ GPR54, also known as the ‘Kisspeptin receptor’ mitigates endocrine functioning during puberty.  Its activation causes the release of gonadotropin hormones.  In short, it is the mechanism that ‘turns on’ the gonads and basically readies the body for sexual procreation.  All of the aches and pains and weird feelings that occur during puberty are a result of the body adjusting to changes in the gonadal system.   The Kisspeptin receptor usually becomes active around age 11 in girls and 12 in boys.  Hiro is 14, which suggests he’s a bit of a late-bloomer in regards to his physical development, but this is not especially uncommon among children who are intellectually precocious.  No one really knows why this is; it’s just a common correlational finding.  

Next it reads ‘High levels of GnRH.’  GnRH is short for gonadotropin-releasing hormone.  This is a peptide hormone that regulates the release of additional hormones in the anterior pituitary gland within the hypothalamus.  These hormones are released in pulses or waves and it’s often different between boys and girls.  In girls, the pulses tend to occur at a varied rate throughout the menstrual cycle, with big surges occurring just prior to ovulation.  In boys, meanwhile, GnRH is secreted in pulses at a more constant frequency.  Detection of high levels of GnRH in Hiro indicates a pulse of the hormone is occurring and his gonads are in a state of spermatogenesis (i.e. his body is creating sperm… which is likely much more information than anyone needs regarding a cartoon character). 

After that it reads ‘increased pituitary activity.’  Again, the pituitary gland is the main generator for these hormones.  Electrical activity generating in the pituitary causes the release of various hormones.  The pituitary is involved in all manner of state and trait-based functioning.  In this case, the heightened activity is most likely connected to the pulse of GnRH. 

Next it reads ‘High Testosterone.’ Testosterone is an androgen steroid hormone secreted in the testicles of males and the ovaries of females.  Higher levels of testosterone during physical development aids in the tissue growth of secondary sexual characteristics, as well as augmenting muscle and bone mass, and the growth of body hair.  Secretion of testosterone from the adrenal glands is also associated with stress, helping to ready muscles tension and blood flow in so-called ‘fight-or-flight’ situations.  Heightened testosterone in Hiro just means that his body is going through the process of puberty; that his body is at an accelerated process of physical development (i.e. a ‘growth spurt’). 

Next, it reads ‘vocal fluctuation,’ which is pretty straightforward.   During puberty, the larynx grows and expands at a fast pace, altering the pitch and vibration of vocal folds.  Similar to GnRH, the hormones that aid in the growth of the larynx also occur in surges or pulses and this is why adolescent voices sometimes seem to ‘crack’ or suddenly fluctuate. 

Finally, it the readout reads ‘emotional instability.’  This is a complex one.  Obviously, a significant portion of Hiro’s emotional issues is related to his morning over his brother’s death.  Nevertheless, emotional instability is highly common during the process of puberty, a byproduct of hormonal fluctuations as well as differential activity in the brain.  Up in the picture, on the viewer’s right side, there are two side-views of Hiro’s brain.  The first is a baseline image, the picture Baymax took when he first met Hiro.  The second is a current image.  These are both imitations of what full side-view brain scans look like on a functional MRI (magnetic resonance imaging). 

Hiro’s baseline shows relatively normative brain activity, with electrical activity occurring in a broad, spectral fashion.  In the second image, however, the electrical activity is more focal, concentrating in the lower mid-brain region.  This is where the hypothalamus is, and the concentrated activity indicates that the pituitary is in the process of triggering the release of all manner of hormones. 

Structurally, the hypothalamus resides right next to the amygdala, part of the limbic system, and a primary component to emotion.  The amygdala is believed to be the part of the brain that connects thoughts and memories to physical sensations.  Put simply, it is what creates emotion.  Being situated so closely to the hypothalamus, an increase in limbic system activity may be merely a byproduct of increases of growth-related hormones during adolescence.  And this often contributes to greater emotional instability tied in with growth spurts. 

Furthermore, the increased activity in the midbrain region often acts to reduce activity in other areas, especially the frontal lobes.  The frontal lobes are the area of the brain most associated with decision-making, foresight, and judgment.  Apparently, there is only so much electrical activity that can occur in the brain at any given moment.  And a concentration of activity in the lower regions can actually reduce such activity in the upper regions.  So, when an adolescent makes a rash decision, acts out, or shows poor judgment, it may often be a result of reduced activity in frontal lobes that occur as a result of heightened activity elsewhere.  And we see this actually occur later on in the movie when Hiro makes a very rash decision and tries to get Baymax to kill Professor Callaghan.  Not only is Hiro still morning Tadashi and feels extremely betrayed by Professor Callaghan, but he’s also at a stage of development where his frontal lobes are at a lower-than-average level of activity… which can lead to rash, impulsive decision-making.  Fortunately, Gogo, Honey and the gang are there to stop Baymax and prevent Hiro from a decision he would ultimately regret.

Finally, the readout also shows Hiro’s heart rate and body temperature, both of which are in the normative range. 

Below the brain scans on the right-hand side is a list of abbreviations of hormones and neurotransmitters.   First is GnRH (or gonadotropin-releasing hormone) already covered above.  Next is LH, which stands for luteinizing hormone.  For girls, luteinizing hormones supports ovarian theca cells in later stages of the menstrual cycle.  In boys, luteinizing hormones helps to activate leydig cells in the testis, assisting in the production of testosterone. 

After that is a figure for FSH.  FSH stands for follicle-stimulating hormone.  FSH is a specific type of luteinizing hormone that activates pubertal maturation.  In girls, FSH is crucial to determining which egg is selected in ovulation.  FSH seems to be able to determine which egg follicle is the strongest and most ready for ovulation (i.e. which egg has the greatest chase of being fertilized and growing into a healthy baby).  In boys, FSH induces sertoli cells to secrete androgen-binding proteins… it helps to activate cells associated with male sexual development. 

Next is T, also known as T3 or Triiodothyronine.   This is a thyroid hormone that plays a significant role in multiple areas of bodily functioning, including metabolism, body temperature, and heart rate.  Elevated levels of T3 is a critical component to adolescent development.  It helps navigate metabolism so to give growing regions the extra energy needed for cellular generation (tissue growth).  For his size and weight, Hiro’s T3 level of 170 definitely suggests he is going through a growth spurt.   

Next is E2, which stands for estradiol.  Estradiol is both a steroid as well as a sex hormone.  It is the primary sex hormone in girls, helping to activate genes whose expression allows further development of the vagina as well as breast growth.  In boys, estradiol acts to help keep nascent sperm cells from dying off prematurely.  Significant heightened E2 levels in boys is a primary indicator of the genetic condition known as Klinefelters syndrome (also known as intersex or XYY syndrome).  At 22, Hiro’s E2 level is a touch high, but well within the normative range for a boy his age. 

And finally, there’s F, which totally perplexes me.  There’s no hormone I can think of that is abbreviated as F. So what’s Hormone F?  I’m still not sure and my best guess is that it’s an in-joke for fans of the anime, Dragonball Z.  

So all of this, this entire business that took me half an hour to write, is detailed in a single scene that lasts maybe ten seconds.  It’s really impressive the amount of detail and research that went into this one scene. 

Ovary - Corpus Luteum

Histology image shows the ovary in overview, the cortex and medulla of the ovary can be clearly seen.

Corpus luteum (yellow body) theca lutein cells and granulosa lutein cells. These cells work together in the production of ovarian hormones that support the initial pregnancy.

Corpus albicans (white body) lack of implantation and associated hCG will lead to this structure not producing hormones.

Atretic follicles are the degenerating follicles from various developmental stages that did not form the ovulating follicle and do not form the corpus luteum.