Rhythm in acetylcholine-acetylcholinesterase system in the slug, Laevicaulis alte (Ferussac, 1821).

Acetylcholine (ACh) and acetylcholinesterase (AChE) in central nervous system (CNS) and foot muscle (FM) of Laevicaulis alte cresting at 0400 h under LD 12:12 (0600 to 1800 : 1800 to 0600 h) regimen are in phase with each other. Nuli hypothesis (Ho) than for FM AChE, was rejected (A not equal to 0) since F (2,3) (0.05) greater than 9.6 ACh and AChE rhythm phase synchronized motor rhythm of Laevicaulis alte.