However, the PPI impairment observed in DBA/2 mice relative to the common C57BL/6 strain is confounded by a concomitant reduction in baseline
startle reactivity. In this study, we examined the robustness of the PPI deficit when this confound is fully taken into account.
Male DBA/2 and C57BL/6 mice were compared in a PPI experiment using multiple pulse stimulus intensities, Selleck Vactosertib allowing the possible matching of startle reactivity prior to examination of PPI. The known PPI-enhancing effect of the antipsychotic, clozapine, was then evaluated in half of the animals, whilst the other half was subjected to two additional schizophrenia-relevant behavioural tests: latent inhibition (LI) and locomotor reaction to the psychostimulants-amphetamine and phencyclidine.
PPI deficiency in DBA/2 relative to C57BL/6 mice was essentially independent of the strain difference in baseline startle reactivity. Yet, there was no evidence that DBA/2 mice were superior in detecting the PPI-facilitating effect of clozapine when startle difference was balanced. Compared with C57BL/6 mice, DBA/2 mice also showed impaired LI and a different check details temporal profile in their responses to amphetamine and phencyclidine.
Relative to the C57BL/6 strain, DBA/2 mice displayed multiple behavioural traits relevant to schizophrenia psycho- and physiopathology, indicative of both dopaminergic
and glutamatergic/N-methyl-d-aspartic acid receptor dysfunctions. Further examination
of their underlying neurobiological differences is therefore warranted in order to enhance the power of this specific inter-strain comparison as a model of schizophrenia.”
“Beneficial effects of caffeine on memory processes have been observed in animal models relevant to neurodegenerative diseases and aging, although the underlying mechanisms remain unknown. Because brain-derived neurotrophic factor (BDNF) is associated with memory formation and BDNF’s actions are modulated by adenosine receptors, the molecular targets for the psychostimulant actions of caffeine, we here compare the effects of chronic caffeine (1 mg/mL drinking solution for 30 days) on short- and long term memory and on levels of hippocampal proBDNF, mature Suplatast tosilate BDNF. TrkB and CREB in young (3 month old) and middle-aged (12 month old) rats. Caffeine treatment substantially reduced i) age-related impairments in the two types of memory in an inhibitory avoidance paradigm, and ii) parallel increases in hippocampal BDNF levels. In addition, chronic caffeine increased proBDNF and CREB concentrations, and decreased TrkB levels, in hippocampus regardless of age. These data provide new evidence in favor of the hypothesis that modifications in BDNF and related proteins in the hippocampus contribute to the pro-cognitive effects of caffeine on age-associated losses in memory encoding.