Decreases in mucosally-evoked tachykinin signaling pathways can explain age-related reductions in murine colonic motility patterns.

Background: Increasing age increases the incidence of chronic constipation and fecal impaction. The contribution of the natural aging process to this phenotype is unclear. This study explored the effects of age on key motility patterns in the murine colon and determined the contribution that altered neurokinin 2 (NK) -mediated signaling made to the aging phenotype.

Age-Associated mRNA and miRNA Expression Changes in the Blood-Brain Barrier.

Functional and structural age-associated changes in the blood-brain barrier (BBB) may affect the neurovascular unit and contribute to the onset and progression of age-associated neurodegenerative pathologies, including Alzheimer's disease. The current study interrogated the RNA profile of the BBB in an ageing human autopsy brain cohort and an ageing mouse model using combined laser capture microdissection and expression profiling. Only 12 overlapping genes were altered in the same direction in the BBB of both ageing human and mouse cohorts.

Gastrointestinal capacity, gut hormones and appetite change during rat pregnancy and lactation.

Pregnancy and lactation increase maternal appetite and adiposity, which in humans can lead to long-term body mass retention. Previous rat reproduction studies suggest that appetite-inhibiting gut hormone, peptide-YY (PYY), is elevated, despite hyperphagia also that gastrointestinal size increases. The present study characterised changes in orexigenic (appetite-stimulating) ghrelin and anorexigenic (appetite-inhibiting) PYY and glucagon-like peptide-1 (GLP-1), and gastrointestinal architecture during pregnancy and lactation, in matched fed and fasted plasma and gut tissue samples taken during the dark phase.

Changes in neuromuscular structure and functions of human colon during ageing are region-dependent.

Objective: To determine if human colonic neuromuscular functions decline with increasing age.

Design: Looking for non-specific changes in neuromuscular function, a standard burst of electrical field stimulation (EFS) was used to evoke neuronally mediated (cholinergic/nitrergic) contractions/relaxations in muscle strips of human ascending and descending colon, aged 35-91 years (macroscopically normal tissue; 239 patients undergoing cancer resection). Then, to understand mechanisms of change, numbers and phenotype of myenteric neurons (30 306 neurons stained with different markers), densities of intramuscular nerve fibres (51 patients in total) and pathways involved in functional changes were systematically investigated (by immunohistochemistry and use of pharmacological tools) in elderly (≥70 years) and adult (35-60 years) groups.

Changes in murine anorectum signaling across the life course.

Background: Increasing age is associated with an increase in the incidence of chronic constipation and fecal impaction. The contribution of the natural aging process to these conditions is not fully understood. This study examined the effects of increasing age on the function of the murine anorectum.