Paternal stress alters synaptic density and expression of GAP-43, GRIN1, M1 and SYP genes in the hippocampus and cortex of offspring of stress-induced male rats.

Adverse experiences during pregnancy have a negative impact on the neuronal structure and behavior of offspring, but the effects of a father's life events on the outcome of progeny are scarce. The present study is intended to investigate whether paternal stress affects the offspring brain structure, especially those regions concerned with learning and formation of memory, namely the hippocampus (HC) and prefrontal cortex (PFC), and also the expression of certain genes linked to learning and memory in the offspring. Induced stress to male rats by five stressors, one per day followed by allowing them to mate with the normal, unstressed female. Synaptophysin immunoreactivity was assessed in the tissue sections of the HC and PFC as well as expression of genes concerned with learning and memory was evaluated by RT-PCR in the progeny of stress-received males. The progeny of stressed rats had reduced antisynaptophysin immunoreactivity in the HC and PFC. The synaptic density in HC was less in the A-S (Offspring of male rats who received stress during adulthood) and PA-S (offspring of male rats who received stress during both adolescence and adulthood) than in P-S (offspring of male rats who received stress during adolescence) and C-C (offspring of control) groups. Similar results were observed even in the PFC. The results of post hoc tests proved that the HC and PFC of the progeny of stress-exposed rats exhibited considerably less synaptic density than control (P<0.05), and the levels of expression of GAP-43, GRIN1, M1, and SYP genes in HC and PFC were down-regulated. This study concludes that paternal adverse experiences can affect the offspring's synaptic plasticity and also the genes, which can regulate learning and formation of memory.

Comparative in vitro evaluation of remaining dentine thickness following instrumentation with hand and rotary endodontic files during pulpectomy in primary molars: a systematic review.

PURPOSE: The aim was to compare the remaining dentine thickness (RDT) following instrumentation with hand and rotary endodontic files during pulpectomy in primary molars. Research question was 'Is there any difference between the remaining dentine thickness following instrumentation with hand and rotary endodontic files during pulpectomy in primary molars?'. METHODS: Electronic Databases like MEDLINE PubMed, Cochrane Library, EBSCOhost, Google scholar and grey literature were searched between January 1, 2006 and August 31, 2022 for in vitro and ex vivo studies that compared hand and rotary endodontic instrumentation to evaluate the RDT in primary molars. Articles published in English or which could be translated into English were searched. Two reviewers independently selected studies, extracted data, assessed risk of bias using the Revised, validated version of MINORS criteria. RESULTS: Twelve studies were included in qualitative analysis. All included studies showed low risk of bias. Six studies showed more RDT with rotary instrumentation compared to manual instrumentation. Whereas, five studies showed variable results for RDT with manual and rotary instrumentation at different levels of root canals. One study showed no significant difference between manual and rotary instrumentation. In view of methodological heterogeneity of the findings, a meta-analysis was not conducted. CONCLUSION: High quality of evidence based on low risk of bias was found in all the included studies. Statistically, rotary instrumentation showed more RDT than manual instrumentation according to majority of studies. Despite the shortcomings of this systematic review, it is possible to infer that the use of rotary instrumentation provides more RDT and thus there is considerable conservation of tooth structure.