The interaction between depression and stroke is highly complex. Post‐stroke depression (PSD) is among the most frequent neuropsychiatric consequences of stroke. Depression also negatively impacts stroke outcome with increased morbidity, mortality and poorer functional recovery. Antidepressants such as the commonly prescribed selective serotonin reuptake inhibitors improve stroke outcome, an effect that may extend far beyond depression, e.g., to motor recovery. The main biological theory of PSD is the amine hypothesis. Conceivably, ischaemic lesions interrupt the projections ascending from midbrain and brainstem, leading to a decreased bioavailability of the biogenic amines – serotonin (5HT), dopamine (DA) and norepinephrine (NE). Acetylcholine would also be involved. So far, preclinical and translational research on PSD is largely lacking. The implementation and characterization of suitable animal models is clearly a major prerequisite for deeper insights into the biological basis of post‐stroke mood disturbances. Equally importantly, experimental models may also pave the way for the discovery of novel therapeutic targets. If we cannot prevent stroke, we shall try to limit its long‐term consequences. This review therefore presents animal models of PSD and summarizes potential underlying mechanisms including genomic signatures, neurotransmitter and neurotrophin signalling, hippocampal neurogenesis, cellular plasticity in the ischaemic lesion, secondary degenerative changes, activation of the hypothalamo‐pituitary‐adrenal (HPA) axis and neuroinflammation. As stroke is a disease of the elderly, great clinical benefit may especially accrue from deciphering and targeting basic mechanisms underlying PSD in aged animals.
RS67333 is a partial serotonin subtype 4 receptor (5-HT4R) agonist that has been widely studied for its procognitive effect. More recently, it has been shown that its ability to promote the nonamyloidogenic cleavage of the precursor of the neurotoxic amyloid-β peptide leads to the secretion of the neurotrophic protein sAPPα. This effect has generated great interest in RS67333 as a potential treatment for Alzheimer’s disease (AD). We show herein that RS67333 is also a submicromolar acetylcholinesterase (AChE) inhibitor and therefore, could contribute, through this effect, to the restoration of the cholinergic neurotransmission that becomes altered in AD. We planned to pharmacomodulate RS67333 to enhance its AChE inhibitory activity to take advantage of this pleiotropic pharmacological profile in the design of a novel multitarget-directed ligand that is able to exert not only a symptomatic but also, a disease-modifying effect against AD. These efforts allowed us to select donecopride as a valuable dual (h)5-HT4R partial agonist (Ki = 10.4 nM; 48.3% of control agonist response)/(h)AChEI (IC50 = 16 nM) that further promotes sAPPα release (EC50 = 11.3 nM). Donecopride, as a druggable lead, was assessed for its in vivo procognitive effects (0.1, 0.3, 1, and 3 mg/kg) with an improvement of memory performances observed at 0.3 and 1 mg/kg on the object recognition test. On the basis of these in vitro and in vivo activities, donecopride seems to be a promising drug candidate for AD treatment.