This is the first of three blogs regarding the role of Hypothalamus with respect to Escaping Titan. As Tyler Yohe and I initially discussed the Synapse Stimulant Implants (SSIs) and how they could be used to provide control of the player-character body, we discussed the idea that an SSI in the hypothalamus could not only convey healing, but a degree of fine control over the more "automatic" functions of the body. Such control could provide greater or lesser sensitivities to pain, heat, cold, hunger, body temperature, and even normal body cycles.
In this respect, the Hypothalamic SSI is the ideal implant for a future astronaut or colonist. Harsh environments, temperature and pressure extremes, micro (or no) gravity, and altered day/night and seasonal cycles all suggest that a Hypothalamic SSI is not just optional, but necessary – hence its inclusion in the scientifically realistic Escaping Titan. In this blog, we will discuss an overview of the function of the hypothalamus. Next month we will discuss the details of hypothalamus structure and location for the "Operation-style" mini-game, then the following month we'll come back to some more details of how control of the hypothalamus can translate to in-game Healing Ability.
In popular culture, it is fairly common knowledge that there is a portion of the nervous system dedicated to the “Fight or Flight” response. We call it the “Sympathetic Nervous System” and it largely consists of a chain of ganglia (clusters of neuron cell bodies) that run parallel to the spinal cord and have origins in the brainstem and thalamus to prepare the body for activity by increasing heart rate, breathing, tighten muscles, dilate pupils and nostrils and flood the bloodstream with adrenaline.
A similar system, the “Parasympathetic Nervous System” serves the functions of “Feed and Breed” and is responsible for hunger, satiety, body temperature, and hormonal control of the body. The origins of the latter are in the hypothalamus, which acts as the brain’s major control interface with many separate systems of the body. Copyright 2013, Sebastian Kaulitzki. Royalty-free image used under license from Shutterstock.
Most of you should be familiar with the common hormones testosterone, estrogen, progesterone produced by testes and ovaries; adrenalin and cortisol produced by adrenal glands, thyroxin, produced by the thyroid gland, and growth hormone, secreted by the pituitary gland. With the exception of growth hormone, each of these hormones is produced outside the brain by specialized tissues that receive extensive blood and neural inputs. In addition to the obvious effects (e.g. reproductive effects and secondary sex characteristics), these hormones have profound effects on muscle development, blood pressure, metabolism, fat deposition, and bone growth.
What is less obvious is that the production of each of these hormones is under strict control of the brain - both through direct neuron connections (i.e. to the adrenal gland), or indirectly through specialized "tropins" or regulatory hormones produced by tissues in the brain. The hypothalamus is as much a "gland" be definition, as it is a nucleus of the brain. Neurons in hypothalamus controls the autonomic (i.e. automatic or involuntary) functions of the nervous system and body, regulate homeostasis - body temperature, blood pressure, digestion, heart rate, respiration rate, etc. - and gives instructions to the pituitary gland (distinctly a gland
and not a nucleus) through specific releasing hormones and inhibiting hormones. In this manner, it also controls the functions of all the other glands, directly or indirectly, of the body, forming what is officially termed the "endocrine" (hormonal) system. Copyright 2013, Alila Medical Images. Royalty-free image used under license from Shutterstock.
The hypothalamus produces antidiuretic hormone (ADH) or vasopressin which regulates smooth muscle contraction around the blood vessels, and hence the blood pressure throughout the body. This is a very important function, since blood must be under pressure to penetrate the small capillaries that serve all tissues of the body. Another important, similar, hormine produced in hypothalamus is oxytocin, which produces contraction in smooth muscle of the mammaries and uterus, promoting lactation and inducing labor during pregnancy. Both hormones are produced by the hypothalamus, but stored and released by the pituitary. This is accomplished by neurons with cell bodies in the hypothalamus, and axon terminals which store and release the hormones onto blood vessels in the posterior pituitary in much the same manner as neurotransmitter release onto other neurons.
A series of "stimulating" or "releasing" hormones are produced and released in the anterior pituitary by neurons that receive inputs from other areas of hypothalamus. Prolactin (stimulates mammary glands), human growth hormone (affects bone and muscle growth), melanocyte stimulating hormone (affects skin color, and has some interesting interactions with the enkephalin/pain system), thyroid stimulating hormone (causes thyroid to produce thyroxin and thyrotropin), adrenocorticotropic hormone (causes the adrenal cortex to produce cortisol, one of the bodies primary stress-response hormones), follicle stimulating hormone (causes the development of follicles and ova in the ovaries and also promotes estrogen synthesis), and lutenizing hormone (causes ovulation, the release of ova from follicles, and transforms the follicle into a "corpus luteum" which produces progesterone).
Along with some lesser known neurotransmitters and neuromodulators produced in various areas of the brain which also have hormone-like functions both within the brain and throughout the body, the hypothalamus is intricately involved in control of the body – its neighbor, the thalamus (and midbrain and spinal cord) is in direct neural control – while the hypothalamus exercises indirect endocrine or hormonal control. Many systems of the body will certainly continue to function with inputs from the rest of the brain, but each of these systems has an override or regulatory function to control every aspect of the body.
Thus the hypothalamus really is
the control center for the whole body. In Escaping Titan, you don't necessarily have to put up with the body
telling you what to do. You
are in control!
Join us next month for Part 2: Hypothalamus – When, Where, & How.