Prefrontal damage in childhood and changes in the development of personality: a case report

Unravelling the genetic basis of Schizophrenia

Neuronal development is a highly regulated mechanism that is central to organismal function in animals. In humans, disruptions to this process can lead to a range of neurodevelopmental phenotypes, including Schizophrenia (SCZ). SCZ has a significant genetic component, whereby an individual with an SCZ affected family member is eight times more likely to develop the disease than someone with no family history of SCZ. By examining a combination of genomic, transcriptomic and epigenomic datasets, large-scale 'omics' studies aim to delineate the relationship between genetic variation and abnormal cellular activity in the SCZ brain. Herein, we provide a brief overview of some of the key omics methods currently being used in SCZ research, including RNA-seq, the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) and high-throughput chromosome conformation capture (3C) approaches (e.g., Hi-C), as well as single-cell/nuclei iterations of these methods. We also discuss how these techniques are being employed to further our understanding of the genetic basis of SCZ, and to identify associated molecular pathways, biomarkers, and candidate drug targets.

Why did humans surpass all other primates? Are our brains so different? Part 2

The second part of this review is an attempt to explain why only Homo sapiens developed language. It should be remarked that this review is based on the opinion of a clinical neurologist and does not intend to go beyond an overview of this complex topic. The progressive development of language was probably due to the expansion of the prefrontal cortex (PFC) and its networks. PFC is the largest area of the human cerebral cortex and is much more expanded in humans than in other primates. To achieve language, several other functions should have been attained, including abstraction, reasoning, expanded working memory, and executive functions. All these functions are strongly related to PFC and language had a profound retroactive impact on them all. Language and culture produce anatomic and physiological modifications in the brain. Learning to read is presented as an example of how culture modifies the brain.

Life-long deficits in social adaptation and the frontal lobes: New evidence, seventy-five years after Ackerly and Benton's landmark case report of JP

The case of JP, reported by Ackerly and Benton in 1948 with a detailed follow-up by Ackerly in 1964, stands as the index case of developmental prefrontal damage and its impact on social adaptation. Although the 1948 case report included findings from a 1933 pneumoencephalogram and exploratory craniotomy, a definitive cause was never established for JP's prefrontal damage. Etiologies were never determined for the left-sided seizures that occurred when JP was age four, nor for the progressive anterograde amnesia that JP developed in middle age. Given Ackerly's thoroughness and long-term follow-up of his patient, it was hoped that a brain cutting would have been done, though no report of a post-mortem examination was published. The lead author of this paper (SB) set out to discover what had happened to JP after Ackerly's 1964 report and whether a brain cutting had in fact occurred. Using a variety of investigative approaches, it was discovered that a post-mortem brain examination had taken place. Those present at the brain cutting were identified, and the still-living witnesses to the brain cutting were interviewed. Previously unpublished, relevant materials were uncovered from archival sources. A film of the brain cutting, as well as photos, were located. A film of Ackerly interviewing JP prior to JP's death at age sixty-four also was found. The authors studied autopsy findings in the newly discovered video and still images. These findings were judged consistent with massive perinatal hemorrhagic damage to both frontal lobes. JP's left-sided seizures were likely due to activation of a focus from his congenital brain damage. The anterograde amnesia that was documented when JP was twenty-five and that was noted to worsen when he was forty-nine remains unexplained but may have been related to slowly progressive hydrocephalus. This paper expands what is known about the case of JP, making it the only report of a person with congenital frontal injury followed for their entire life including post-mortem brain examination.

Moral Reasoning in Children with Focal Brain Insults to Frontotemporal Regions

Neuroscientific evidence indicates that human social functioning is supported by a distributed network of frontal and temporal brain regions that undergoes significant development during childhood and adolescence. Clinical studies of individuals with early brain insults (EBI) to frontotemporal regions suggest that such lesions may interfere with the maturation of sociocognitive skills and lead to increased sociobehavioural problems. However, little attention has focussed on the direct assessment of sociocognitive skills, such as moral reasoning, following focal EBI. In the present study, the performance of 15 patients with focal EBI (8–16 years) was compared to that of 15 demographically matched controls on basic neuropsychological measures (IQ and executive functions), sociocognitive tasks (moral reasoning, moral decision-making and empathy) and parent reports of sociobehavioural problems and social adaptive skills. Patients with focal EBI had significantly lower levels of moral reasoning maturity, moral decision-making, and empathy than their matched controls, but did not differ on more general measures of cognition. Their parents also reported increased sociobehavioural problems. These findings suggest that focal EBI to frontotemporal regions can result in reduced sociocognitive capacities, more specifically moral reasoning, and increased vulnerability to sociobehavioural problems.