Central acetylcholine synthesis and catabolism activities in the cuttlefish during aging.

Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activities, measured in 10 central regions of young, middle-aged and old cuttlefish, showed a regional heterogeneity but with different age-related distribution patterns. Maximal acetylcholine synthesis and catabolism were observed in the inferior frontal and the optic lobes. Important age-related decreases in ChAT activities were evidenced in most regions, while only moderate variations were found for AChE. Since the superior frontal lobe is involved in visual learning, the dramatic decrease in ChAT activity observed in this lobe (-77%) could be implicated in the learning deficits reported in senescent Sepia.