An in vitro analog of learning that food is inedible inAplysia: decreased responses to a transmitter signaling food after pairing with transmitters signaling failed swallowing

Abstract

An in vitro analog of learning that a food is inedible provided insight into mechanisms underlying the learning.Aplysialearn to stop responding to a food when they attempt but fail to swallow it. Pairing a cholinergic agonist with an NO donor or histamine in theAplysiacerebral ganglion produced significant decreases in fictive feeding in response to the cholinergic agonist alone. Acetylcholine (ACh) is the transmitter of chemoreceptors sensing food touching the lips. Nitric oxide (NO) and histamine (HA) signal failed attempts to swallow food. Reduced responses to the cholinergic agonist after pairing with NO or HA indicate that learning partially arises via a decreased response to ACh in the cerebral ganglion.