Mean ICV was calculated separately by each year of age for ages below 15 because the volume increase year by year was enormous. Mean ICV was calculated as a single mean for participants above the age of To prevent a possible Type I error due to multiple tests, a Bonferroni correction was applied for correlation analyses. Scatter plots representing the amygdale and hippocampi are illustrated in Figs. Therefore, this approach is useful for identifying data patterns that may otherwise be overlooked by using curve-fitting procedures that assume a specific shape [24].
These results were consistent after adjustment and division by sex Table 2. Table 2 shows the peak ages calculated using the estimated cubic models. The female group reached its local maximal volume earlier than the male group in all regions.
In addition, the left amygdala LA reached its peak around 1. Given that our earlier work found evidence for a peak growth spurt at around two years of age [9] , boys and girls aged 1 to 24 months were included in the Infant category. Figures 4 and 5 depict growth changes of the amygdala and hippocampus until the peak age, all of which showed a rapid volume increase in the first few months from birth regardless of sex.
The female LA growth change was larger for the first few years when adjusted, but its rate decreased earlier than that of the males Fig. The growth change of the RA was smaller than that of the LA, but its sexual difference trend was similar Fig.
The rates of monthly volume changes in the right and left amygdala. Positive values indicate increasing volume. The point of intersection on the x-axis represents the age of local maximal volume. Black line: whole group, blue line: males, red line: females. The rates of monthly volume changes in the right and left hippocampus. In the hippocampus, the female and male groups revealed similar curves in raw LH and RH, but after adjustment the females showed a greater increase during the first several years Fig.
The growth rate change of the whole brain volume also showed a large increase during the first several years of life, and the males displayed a larger growth change across time than the females did. However, after adjustment by ICV, these differences became less obvious.
Figure 6 shows the relationship between age and laterality index. Blue square and blue line: male. Red circle and red line: female. The volumes of the whole brain, amygdale and hippocampi exhibited significant age-related changes from infancy to early adulthood, even after adjustment by ICV.
The cubic models best characterized the estimated developmental trajectories of all the given brain regions, regardless of sex, or hemispheric differences. For the whole brain, the cubic model was consistent with a previous study by Lenroot, et al [5]. However, to our knowledge, no previous study has estimated the non-linear developmental models of the amygdala of healthy humans from infancy to early adulthood.
Giedd [1] reported no volumetric changes of amygdala in females between 4 and 18 years of age. The results of the present study indicated that the maximum volume of the amygdala was reached between 9 and 11 years of age. Moreover, the study showed a non-linear, age-related increase in development after 4 years in both males and females. This result, which is inconsistent with Giedd et al [1] might have been caused by the inclusion of data from infants and toddlers, who showed a robust increase in amygdalar volume during the period of the present study.
Mosconi et al. The present findings appear to bridge the gap between the results of these two previous studies [1] , [12]. The hippocampus also showed a non-linear developmental pattern, with volume increases in both hemispheres until approximately 9 to 11 years of age.
This result was not consistent with previous findings in 4 to 18 year olds. However, other studies have reported volumetric changes in hippocampal sub-regions during this age [25]. Suzuki et al. Moreover, a postmortem study by Benes [27] showed that myelination in the subicular and presubicular regions of the hippocampus continued until adulthood. Furthermore, animal studies [28] have shown that the hippocampus is a region where neurogenesis occurs until adulthood.
The results of the current study corroborate these previous findings. Complex interactions among genetic factors, environmental conditions, as well as changes in these factors, strongly contribute to volume changes in subcomponents of the brain [29]. Such complex interactions might result in large individual variations in amygdalar and hippocampal development causing statistically inconsistent results.
The present results also corroborated previous studies by showing that the peak age of whole brain development occurred earlier in females, than in males, with the exception that the peak age reported in this study happened earlier than has been reported in previously [1] , [3] , [5].
Our results were also consistent with previous studies in showing that males had larger whole brain volumes than females [1] , [3] , [5]. Moreover, the results of this study showed that the right and left amygdala tended to be larger in males than in females.
Similar to the whole brain, the female amygdala reached its peak volume approximately 18 months earlier than the male amygdala. In addition, changes in the growth rate of the amygdala decreased earlier in females.
These findings suggest that the longer growth period of the amygdala might contribute to the larger male amygdala. Animal studies have indicated that the amygdala has rich receptors for male hormones androgen , which promotes myelinogenesis [16] , [30]. Consequently, myelinogenesis might contribute to increases in the volume of the amygdala in males.
Interestingly, however, changes in the growth of the amygdala relative to the intracranial volume were larger in females at the beginning of life, indicating that growth factors affecting the amygdala may change as a result of age and sex. Our results also indicated that the raw hippocampal volumes of males were larger than those of females. Sex differences in changes in absolute hippocampus growth were less obvious compared to those of the amygdala, relative growth changes of the female left hippocampus were larger than those of males in the first years of life.
Gogtay et al. Thus, the larger growth change of the left hippocampus in females might be the result of development in posterior hippocampal sub region. Furthermore, only the female hippocampus laterality index changed significantly as a result of age, causing left and right volumes to become more symmetrical as age increased. It has been reported that females tend to use both hemispheres for information processing through the larger commissural systems [21] , which might contribute to symmetrizing the bilateral hippocampi, and to refining and developing strong connections, even after the formation of neural networks are completed.
Such knowledge about sexual dimorphism could be a helpful to understand psychiatric disorders and diseases with different prevalence rates between males and females [5] , [18] , [25] , [26] , [31] — [33]. Courtesy of Gogtay et al. For an animated version click here. Please read the Duke Wordpress Policies. Contact the Duke WordPress team. The Alcohol Pharmacology Education Partnership. Schwartz-Bloom, Ph. Fulton T. Cross-sectional area of the posterior hippocampus in autistic patients with cerebellar and corpus callosum abnormalities.
Neurology ; 45 : — Sapolsky RM. Glucocorticoids and hippocampal atrophy in neuropsychiatric disorders. Arch Gen Psychiatry ; 57 : — J Autism Dev Disord ; 10 : 91 — Seress L. Morphological variability and developmental aspects of monkey and human granule cells: differences between the rodent and primate dentate gyrus. Epilepsy Res Suppl ; 7 : 3 — Neuronal connections, cell formation and cell migration in the perinatal human hippocampal dentate gyrus. Cesk Fysiol ; 47 : 42 — Psychiatric disorders in children and adolescents with mental retardation and active epilepsy.
Arch Neurol ; 53 : — Feedforward excitation of the hippocampus by afferents from the entorhinal cortex: redefinition of the role of the trisynaptic pathway. Oxford University Press is a department of the University of Oxford.
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Volume Article Contents Abstract. Development of the hippocampal formation from 2 to 42 years: MRI evidence of smaller area dentata in autism. Osamu Saitoh , Osamu Saitoh. Oxford Academic.
Google Scholar. Christina M. Eric Courchesne. Revision received:. Select Format Select format. Permissions Icon Permissions. Abstract Autism, a neuropsychiatric disorder that severely impairs social, language and cognitive development, has a clinical onset in the first years of life.
Age years. History of seizures. Co-occurring medical conditions. Restricted and repetitive. ADI communication scores are reported separately for verbal and non-verbal autistic subjects verbal subjects: sum of verbal and non-verbal communication scores; non-verbal subjects: non-verbal communication score only.
Ranges for ADI subscales for a diagnosis of autism: Social Impairment 10—30 , Restricted and Repetitive Behaviours 3—12 , Communication Impairment; verbal subjects 8—26 , non-verbal subjects 7— All autistic subjects were negative for fragile X chromosome as determined by DNA or chromosomal analysis. Open in new tab. Open in new tab Download slide. J Comp Neurol. Curr Opin Neurobiol. Exp Brain Res. A J Psychiatry. Nat Med. Neurosci Biobehav Rev. Ann Neurol.
Trends Neurosci. J Neuropathol Exp Neurol. Neurobiol Dis. Exp Neurol. Neuropathol Appl Neurobiol. J Autism Dev Disord. Acta Neuropathol Berl. Arch Gen Psychiatry. Epilepsy Res Suppl.
Cesk Fysiol. Arch Neurol. Download all slides. View Metrics. Email alerts Article activity alert. Advance article alerts. New issue alert. Subject alert. Receive exclusive offers and updates from Oxford Academic. Citing articles via Web of Science Navigating the recurrent perplexity of prefrontal function.
Researchers have restored brain plasticity in the visual cortex of middle-aged mice to that of a younger state by manipulating a gene called Arc. What is the hippocampus? Medically reviewed by Daniel Murrell, M. Function What can go wrong? Diseases that affect the hippocampus What happens if the hippocampus is small? Current research The hippocampus is a part of the brain.
What can go wrong? Diseases that affect the hippocampus. What happens if the hippocampus is small? Current research. Exposure to air pollutants may amplify risk for depression in healthy individuals. Costs associated with obesity may account for 3. Related Coverage. Reading aloud boosts memory Want to improve your memory? Adult brains make no new 'memory' cells The birth of new neurons in the human hippocampus declines steeply in childhood and is 'undetectable' in adulthood, according to a challenging new… READ MORE.
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Making an older brain younger by manipulating a single gene Researchers have restored brain plasticity in the visual cortex of middle-aged mice to that of a younger state by manipulating a gene called Arc.
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