I wish to learn things about the vagus nerve (my enemy, my ally)
AMAZING. and that's a mood lol... the vagus nerve really has a lot to answer for given its contribution to the hyphen in the gut-brain axis
i'm mostly interested in this topic as it relates to the neuroscience of trauma, so lately i've been reading people arguing about whether or not polyvagal theory is bunk (probably). the theory builds on the foundation of the autonomic nervous system (which regulates involuntary processes like breathing and digestion) as split into the sympathetic (which activates our bodies and gets them ready for fight-or-flight type stuff) and parasympathetic (which calms our bodies down) nervous systems, with the vagus nerve being part of the latter.
but the psychologist/neuroscientist stephen porges further proposed that the parasympathetic nervous system is itself split into two more parts: one "more evolved" part associated with mammalian impulses to regulate ourselves through social connection, and one "less evolved" part that follows reptile and amphibian impulses to freeze when stressed. (he proposed this theory in 1994, but this paper from 2011 was fairly readable for me as a non-scientist.) this got people who study trauma (like my problematic fave bessel van der kolk) excited because a big issue with ptsd is overactivation of the autonomic nervous system--what if we could hack the vagus nerve and make it settle down just by making and nurturing social connections? unfortunately, there doesn't seem to be a lot of evidence for the evolutionary or physiological mechanisms behind the theory (check out this review from 2023 roasting the whole concept). porges still has like, many books published by norton (one coming out this august) and plenty of influence in the field, though.
also, this definitely doesn't close the book on the vagus nerve as a potential site for trauma treatment--now it seems like vagus nerve stimulation is the hot new thing (either using an actual device to do this or through ~self-care stuff like meditating and splashing cold water on your face).
i... don't know if any of this is something you wanted to know, but i had fun writing it instead of packing for my flight tomorrow so thanks