| Acetylcholine (ACh) is involved in many functions in the central nervous system, including cognition, learning and the sleep/wake cycle. Acetylcholinesterase (AChE) regulates cholinergic neurotransmission. Because AChE knockout mice survive into adulthood, it has been hypothesized that a related enzyme, butyrylcholinesterase (BuChE) partially compensates for AChE loss and that other neurotransmitter systems might also compensate for loss of cholinergic functions. Wild type and AChE knockout mice have been used to investigate neuroanatomical relationships among neurotransmitter systems that interact with cholinergic systems. Chemical markers were mapped in wild type and knockout mice. Cholinergic markers (ChAT, VAChT, AChE and BuChE), nitrergic and serotonergic markers were unchanged. In AChE knockout mice, TH immunoreactivity was reduced in the locus coeruleus. This study presents a comprehensive overview of the spatial relationships of neurochemically defined neuronal systems in wild type, heterozygous AChE and homozygous AChE knockout mice. |
