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In the study, 12 (6 females, 6 males) healthy adult New Zealand rabbits were used to examine the morphometrical and stereological values. White matter, gray matter and total segment volume of the segments in the pars lumbalis were calculated by Cavalieri's principle. The findings were grouped according to sexand statistically evaluated. As a result, 38% of the length of the spinal cord in rabbits belonged to the pars lumbalis. The morphometric parameters were not statistically different between male and female rabbits (p > 0.05). The segment with the biggest volume was L5. White matter's greatest volume was the L4 segment. The volume of gray matter was enormous in the L6 segment in both genders. When the average volume of lumbal segments was compared according tosex, there was no statistically significant difference (p > 0.05). However, the volume of each segment was greater in male rabbits than in females. In bothsexes, when the correlation values of the volume were compared with the weight and head-tail length of the rabbit, it was observed that this value was not statistically significant (p > 0.05). As a result, this study is thought to be a reference to the researchers to review the neuroanatomy of the lumbal part of the spinal cord in New Zealand rabbits and to localize the neurological studies to be conducted in this type. [ABSTRACT FROM AUTHOR]

Background: Neurocognitive outcomes beyond childhood in people with a Fontan circulation are not well defined. This study aimed to investigate neurocognitive functioning in adolescents and adults with a Fontan circulation and associations with structural brain injury, brain volumetry, and postnatal clinical factors.Methods: In a binational study, participants with a Fontan circulation without a preexisting major neurological disability were prospectively recruited from the Australia and New Zealand Fontan Registry. Neurocognitive function was assessed by using Cogstate software in 107 participants with a Fontan circulation and compared with control groups with transposition of the great arteries (n=50) and a normal circulation (n=41). Brain MRI with volumetric analysis was performed in the participants with a Fontan circulation and compared with healthy control data from the ABIDE I and II (Autism Brain Imaging Data Exchange) and PING (Pediatric Imaging, Neurocognition, and Genetics) data repositories. Clinical data were retrospectively collected.Results: Of the participants with a Fontan circulation who had a neurocognitive assessment, 55% were male and the mean age was 22.6 years (SD 7.8). Participants with a Fontan circulation performed worse in several areas of neurocognitive function compared with those with transposition of the great arteries and healthy controls (P<0.05). Clinical factors associated with worse neurocognitive outcomes included more inpatient days during childhood, younger age at Fontan surgery, and longer time since Fontan procedure (P<0.05). Adults with a Fontan circulation had more marked neurocognitive dysfunction than adolescents with a Fontan circulation in 2 domains (psychomotor function, P=0.01 and working memory, P=0.02). Structural brain injury was present in the entire Fontan cohort; the presence of white matter injury was associated with worse paired associate learning (P<0.001), but neither the presence nor severity of infarct, subcortical gray matter injury, and microhemorrhage was associated with neurocognitive outcomes. Compared with healthy controls, people with a Fontan circulation had smaller global brain volumes (P<0.001 in all regions) and smaller regional brain volumes in most cerebral cortical regions (P<0.05). Smaller global brain volumes were associated with worse neurocognitive functioning in several domains (P<0.05). A significant positive association was also identified between global brain volumes and resting oxygen saturations (P≤0.04).Conclusions: Neurocognitive impairment is common in adolescents and adults with a Fontan circulation and is associated with smaller gray and white matter brain volume. Understanding modifiable factors that contribute to brain injury to optimize neurocognitive function is paramount. [ABSTRACT FROM AUTHOR]