Ivan R. Minev, Daniel J Chew, Evangelos Delivopoulos, James W Fawcett, and Stéphanie P Lacour High Sensitivity Recording of Afferent Nerve Activity Using Ultra-Compliant Microchannel Electrodes: An Acute in Vivo Validation Journal of Neural Engineering 9, no. 2: 026005 (2012) (dresden-ipp.de)
Although 5 - HT3 receptors play a role in afferent signaling in taste buds, the full neural taste response clearly involves other neurotransmitter receptors. (jneurosci.org)
In addition to the microbiota themselves, the GI tract is also home to roughly 50,000 extrinsic and 100 million intrinsic sensory afferent neurons in the enteric nervous system. (ellenratliffrd.com)