  Alzheimer's disease (AD) is an age-specific neurodegenerative disease that
compromises cognitive functioning and impacts the quality of life of an
individual. Pathologically, AD is characterised by abnormal accumulation of
beta-amyloid (A$\beta$) and hyperphosphorylated tau protein. Despite research
advances over the last few decades, there is currently still no cure for AD.
Although, medications are available to control some behavioural symptoms and
slow the disease's progression, most prescribed medications are based on
cholinesterase inhibitors. Over the last decade, there has been increased
attention towards novel drugs, targeting alternative neurotransmitter pathways,
particularly those targeting serotonergic (5-HT) system. In this review, we
focused on 5-HT receptor (5-HTR) mediated signalling and drugs that target
these receptors. These pathways regulate key proteins and kinases such as GSK-3
that are associated with abnormal levels of A$\beta$ and tau in AD. We then
review computational studies related to 5-HT signalling pathways with the
potential for providing deeper understanding of AD pathologies. In particular,
we suggest that multiscale and multilevel modelling approaches could
potentially provide new insights into AD mechanisms, and towards discovering
novel 5-HTR based therapeutic targets.
