“From general electrical response of different parts of the plant, he proceeded to record responses from individual cells using microelectrode recording system devised by him. In those early years, prior to the 1920s, such microelectrode studies had not yet been initiated on single neurons in animals. On the basis of a large number of studies, Bose concluded that plants – small or big – have a nervous system akin to one in the lower animals. He reported, “Plants also have receptors for stimuli, conductors (nerves) which electrically code and propagate the stimulus and efferent or terminal motor organs””
Read more: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6702694/