The hippocampus is a stream processor, responsible for integrating, degrading, and conforming information maps between (primary) external and (inferior) internal systems.
The conformancy function is largely provided by a region of the hippocampus called the “CA2” (not to be confused with Calcium), which has a significant role in mapping and modulating “expectation” state against “current” state.
Nearly all “disorders of consciousness” from “autism” to “schizophrenia” are etiologically differences in circuit integration and conformation compared to expectation in this this region. For example, most phenotypes of “autism” exhibit circuit differences between a region of the hippocampus hypothalamus called the mammillary bodies (sub region, supramammillary nucleus) and the CA2 region of the hippocampus, while “pscyhosis” is the effect of “little astrocyte” signalling across the CA2->CA1 regions.
I think I’ve described the “cognitive” effect of the CA2 as being the fire in Plato’s cave, it transforms the raw data into computationally less intensive and more easily modifiable shadows to plan behavior against.
The CA2 region is the “youngest” hippocampal region in mammals, and is largely the ultimate target for “social information” integration in mammals of all types.
A new AAV tool for highly preferentially targeting hippocampal CA2 – I don’t think this isolates the full range of CA2 expression enough, wish labs would be less dependent on vendor animals, even “wild type” doesn’t really mean “wild” (read: natural).
The CA2 hippocampal subfield in humans: A review – Would be awesome if we could get away from thinking about nervous systems in terms of “function/dysfunction” (slapping my own hand here for the intro here).
Posterior hippocampal CA2/3 volume is associated with autobiographical memory recall ability in lower performing individuals – Ventral CA2 volume should be associated with recall in all individuals, however a circuit imbalance might be why the individual was “lower performing”.
Social odor discrimination and its enhancement by associative learning in the hippocampal CA2 region – This reminds me of Toucan Sam for some reason, but drifting along the air currents toward piss doesn’t seem quite as PG. Chemical signature analysis is almost certainly the first cellular “sense” to develop.
Defining hippocampal area CA2 in the fox (Vulpes vulpes) brain – “autistic” foxes? Yeah, probably.
5HT1AR-FGFR1 Heteroreceptor Complexes Differently Modulate GIRK Currents in the Dorsal Hippocampus and the Dorsal Raphe Serotonin Nucleus of Control Rats and of a Genetic Rat Model of Depression – Pro tip, differences in brainstem/midbrain signalling are literally “depression”/”anxiety”. They aren’t “disease”, they are response states.
Hippocampal subfield vulnerability to α-synuclein pathology precedes neurodegeneration and cognitive dysfunction – Interesting pre-print. Generally, dementia becomes “disease” depending on where the protein “dysfunction” ends up.
Inhibitory control of sharp-wave ripple duration during learning in hippocampal recurrent networks – “waves” are artifacts of metabolic processes, not drivers of them. But does it matter when you average the cart and the horse together?
Development of human hippocampal subfield microstructure related to associative inference – Human brains are too complex and thoughts are made of wishy thinking! (That show aged badly).
Hippocampal oscillatory dynamics in freely behaving rats during exploration of social and non-social stimuli – Humans are unique in that we weight social stimuli a lot heavier than nearly all animals except maybe ants.
Activation of the CA2-ventral CA1 pathway reverses social discrimination dysfunction in Shank3B knockout mice – A “cure” for “Asperger’s” phenotype? Maybe we don’t have to sterilize all “autistic” kids afterall?!?!
Mechanisms of mGluR-dependent plasticity in hippocampal area CA2 – It doesn’t work like we thought it did?
Alteration of hippocampal CA2 plasticity and social memory in adult rats impacted by juvenile stress – The only hope is the sweet sweet release of death. (The work is dumb btw).
Changes in the volumes and asymmetry of subcortical structures in healthy individuals according to gender – Would sure be helpful to people getting twisted into knots over this stuff if we stopped asserting stuff like this without attempting to demonstrate what “gender” actually looks like across the range of expression.
Silencing hippocampal CA2 reduces behavioral flexibility in spatial learning – However it also grants magical “focus” abilities when on track.