Global cerebral ischemia in adolescent male Long Evans rats: Effects of vanillic acid supplementation on stress response, emotionality, and visuospatial memory

Global Cerebral Ischemia in Male Long Evans Rats Impairs Dopaminergic/ΔFosB Signalling in the Mesocorticolimbic Pathway Without Altering Delay Discounting Rates

“…As mentioned, while such a disregard for the anxiogenic properties of the EPM has historically been interpreted as reduced anxiety-like behaviours, a possible link to impaired behavioural inhibition has also been discussed by these authors ( Plamondon and Khan, 2005 ; Milot and Plamondon, 2009 ). Due to growing literature replicating such results, it has been hypothesised in recent years that this could be indicative of decreased inhibitory control, possibly reflecting behavioural impulsivity ( Knowles et al, 2016 ; Morin et al, 2021 ). Previous studies have interpreted increased open-arm time in the EPM and decreased latency to the centre of the OFT as potential indicators of impulsivity ( Ueno et al, 2002 ; Binder et al, 2004 ), although this interpretation requires further investigation ( Rico et al, 2019 ).…”

“…Appropriate dosage was spread onto a small piece of surgical tape and stuck to the cage wall until ingestion. This analgesia delivery method has been used previously and has the advantage of not interfering with the ischemic process ( Kalliokoski et al, 2010 ; Morin et al, 2021 ). If the dose had not been consumed by the time the next dose was to be given, a subcutaneous Bup HCl injection (0.05 mg/ml; Vetergesic© Multidose, Ceva Animal Health, Canada) was administered instead.…”

“…Interestingly, research has reported GCI rats to show behavioural responses that could indicate a rise in impulsivity and/or behavioural disinhibition after infarct, although these remained formally uncharacterised. Notably, in the Elevated-Plus Maze (EPM), ischemic rats show increased open arm exploration and reduced risk assessment behaviours ( Plamondon and Khan, 2005 ; Yan et al, 2007 ; Knowles et al, 2016 ; Lu et al, 2016 ; Morin et al, 2021 ). Such responses, commonly interpreted as reduced anxiety, appear atypical considering the post-ischemic dysregulation of the hypothalamo-pituitary-adrenal axis, which results in elevated stress-induced corticotropin-releasing hormone and corticosterone (CORT) release, in part due to hippocampal injury affecting negative feedback mechanisms ( Barra de la Tremblaye and Plamondon, 2016 ).…”