Not sure what you're looking for specifically, but a quick search for Spinal Nerve (or bundle!) Processing will give you a ton of results. Restrict yourself to pub med or google scholar, because there are a lot of mediocre results.

I think the main confusion here was over the definition of 'absorb'. Your version is much narrower than I'd use. The sensory molecular pathways and accompanying structure of nerves themselves produce significant processing right at the outset which your definition would entirely discount. There is no reason to discount what would otherwise become 'pre-processing' in your model.