The maturation of the acetylcholine system in the dentate gyrus of gerbils (Meriones unguiculatus) is affected by epigenetic factors

Abstract

The current study investigated the influence of impoverished rearing (IR) conditions and a single early methamphetamine challenge (MA; 50 mg/kg i.p.) on day 14 on the postnatal maturation of acetylcholinesterase-positive (AChE+) fibres in the hippocampal dentate gyrus (DG) of gerbils (Meriones unguiculatus). The layer-specific densities of histochemically stained AChE+ fibres were quantified in two planes of the left and right DG in young adults (day 90). Compared to enriched reared (ER) animals, the AChE+ fibre densities turned out to be higher in both the septal and the temporal plane of both hemispheres in saline treated IR and MA treated ER gerbils. The temporal plane was slightly more affected than the septal plane. In IR animals, MA treatment selectively diminished the AChE+ fibre densities in the subgranular layer of both left and right temporal DG. In conclusion, the maturation of AChE+ fibres is vulnerable to both rearing conditions and early MA challenge. The results correlate with our previous studies on the dentate cell proliferation rates and the serotonergic innervation, two parameters which are similarly affected by the experimental design. Thus, disturbances of the ACh system may impair the hippocampal plasticity and hippocampus-related cognitive and emotional function.

Developmental neuroplasticity and the origin of neurodegenerative diseases

“…This leads to an aberrant maturation of prefrontal efferences to ipsiand contralateral parietal and limbic areas Witte et al 2007b) as well as behavioural abnormalities (Winterfeld et al 1998). In contrast to the hypoinnervation of the prefrontal cortex, dopaminergic, cholinergic and serotoninergic innervation of subcortical and limbic structures is enhanced (Busche et al 2002(Busche et al , 2004(Busche et al , 2006.…”

A sorting system with automated gates permits individual operant experiments with mice from a social home cage

“…What is needed now are methods that minimize human interaction with the animals and that greatly reduce experimenter time. Furthermore, during longer experiments animals should remain in contact with their social group, since isolated housing can lastingly affect developmental modification of neural systems and behavior (Olsson and Westlund, 2007;Winterfeld et al, 1998;Busche et al, 2006). Recently, Gallistel and coworkers presented a live-in operant environment with the operant box connected to the home cage in a dual cage system permitting highly efficient, 24/7 long-term investigations of multiple learning and memory parameters through successive experiments (Gallistel et al, 2010).…”

Choline status and neurodevelopmental outcomes at 5 years of age in the Seychelles Child Development Nutrition Study

“…As the brain continues to develop rapidly during childhood, nutrition is likely to continue to have an impact on neurodevelopment in the preschool years ( 19 ) . Plasma free choline, for example, is a precursor of the endogenous neurotransmitter ACh and disturbances of the ACh system may impair hippocampus-related cognitive and emotional function ( 20 ) . Also, epigenetic mechanisms, including DNA methylation, function in the neurobiology of cognition ( 21 , 22 ) and provide plausible mechanisms for a role for choline in development.…”