1. Epstein T, Saltzman-Benaiah J, O’Hare A, Goll JC, Tuck S. {{Associated features of Asperger Syndrome and their relationship to parenting stress}}. {Child Care Health Dev};2008 (Jul);34(4):503-511.
BACKGROUND: Studies have shown an increased level of stress in parents of autistic children relative to parents of non-autistic children. Few studies have examined parenting stress specifically within the Asperger Syndrome (AS) population. Children with AS often have associated difficulties such as sensory sensitivities and problems with executive functioning (i.e. planning, inhibiting, shifting set). This study was designed to study parenting stress as well as to consider the relationship between parenting stress and some of the associated difficulties of AS. More specifically, the aims of this study were to demonstrate the following: that, as a group, parents of children with AS would report elevated levels of parenting stress, a finding which may be more significant for mothers than fathers; that children with AS show impairment in executive functioning as well as heightened sensory sensitivity according to parent report; that parent report of their child’s demanding characteristics would be positively associated with their self-reported levels of parenting stress. METHODS: Participants in this study were the parents of 39 children between the ages of 5 and 12 years, reflecting a 71% response rate, in the Lothian region of Scotland who completed The Parenting Stress Index, the Behavioural Rating Inventory of Executive Function and the Short Sensory Profile. RESULTS: The study revealed that both mothers and fathers of AS children reported elevated levels of parenting stress. There was a significant positive correlation between mother’s parenting stress and the child’s level of impairment, both with respect to executive dysfunction as well as sensory difficulties. CONCLUSION: The challenges of parenting a child with AS should not be underestimated. Further study is needed to explore the causative role that child impairments play in parenting stress and what types of interventions may prove most helpful to these families.
2. Gargus JJ. {{Genetic calcium signaling abnormalities in the central nervous system: seizures, migraine, and autism}}. {Ann N Y Acad Sci};2009 (Jan);1151:133-156.
The calcium ion is one of the most versatile, ancient, and universal of biological signaling molecules, known to regulate physiological systems at every level from membrane potential and ion transporters to kinases and transcription factors. Disruptions of intracellular calcium homeostasis underlie a host of emerging diseases, the calciumopathies. Cytosolic calcium signals originate either as extracellular calcium enters through plasma membrane ion channels or from the release of an intracellular store in the endoplasmic reticulum (ER) via inositol triphosphate receptor and ryanodine receptor channels. Therefore, to a large extent, calciumopathies represent a subset of the channelopathies, but include regulatory pathways and the mitochondria, the major intracellular calcium repository that dynamically participates with the ER stores in calcium signaling, thereby integrating cellular energy metabolism into these pathways, a process of emerging importance in the analysis of the neurodegenerative and neuropsychiatric diseases. Many of the calciumopathies are common complex polygenic diseases, but leads to their understanding come most prominently from rare monogenic channelopathy paradigms. Monogenic forms of common neuronal disease phenotypes-such as seizures, ataxia, and migraine-produce a constitutionally hyperexcitable tissue that is susceptible to periodic decompensations. The gene families and genetic lesions underlying familial hemiplegic migraine, FHM1/CACNA1A, FHM2/ATP1A2, and FHM3/SCN1A, and monogenic mitochondrial migraine syndromes, provide a robust platform from which genes, such as CACNA1C, which encodes the calcium channel mutated in Timothy syndrome, can be evaluated for their role in autism and bipolar disease.
3. Mosconi MW, Kay M, D’Cruz AM, Seidenfeld A, Guter S, Stanford LD, Sweeney JA. {{Impaired inhibitory control is associated with higher-order repetitive behaviors in autism spectrum disorders}}. {Psychol Med};2009 (Jan 21):1-8.
BACKGROUND: Impairments in executive cognitive control, including a reduced ability to inhibit prepotent responses, have been reported in autism spectrum disorders (ASD). These deficits may underlie patterns of repetitive behaviors associated with the disorder.MethodEighteen individuals with ASD and 15 age- and IQ-matched healthy individuals performed an antisaccade task and a visually guided saccade control task, each with gap and overlap conditions. Measures of repetitive behaviors were obtained using the Autism Diagnostic Inventory – Revised (ADI-R) and examined in relation to neurocognitive task performance. RESULTS: Individuals with an ASD showed increased rates of prosaccade errors (failures to inhibit prepotent responses) on the antisaccade task regardless of task condition (gap/overlap). Prosaccade error rates were associated with the level of higher-order (e.g. compulsions, preoccupations) but not sensorimotor repetitive behaviors in ASD. CONCLUSIONS: Neurocognitive disturbances in voluntary behavioral control suggest that alterations in frontostriatal systems contribute to higher-order repetitive behaviors in ASD.
4. Shultz SR, Macfabe DF, Martin S, Jackson J, Taylor R, Boon F, Ossenkopp KP, Cain DP. {{Intracerebroventricular injections of the enteric bacterial metabolic product propionic acid impair cognition and sensorimotor ability in the Long-Evans rat: Further development of a rodent model of autism}}. {Behav Brain Res};2008 (Dec 30)
Propionic acid (PPA) is a dietary short chain fatty acid and a metabolic end-product of enteric bacteria. Intracerebroventricular (ICV) injections of PPA can result in brain and behavioral abnormalities in rats similar to those seen in humans suffering from autism. To evaluate cognition and sensorimotor ability in the PPA model, male Long-Evans hooded rats received ICV injection of PPA or control compounds prior to behavioral testing in water maze and beam tasks. Compared to controls, PPA-treated rats were impaired in the water maze task as indicated by an unusual pattern of mild or no impairment during spatial acquisition training, but marked impairment during spatial reversal training. PPA-treated rats were also impaired on the beam task. Neuropathological analysis from PPA-treated rats revealed an innate neuroinflammatory response. These findings add to evidence that PPA can change the brain and behavior in the laboratory rat consistent with symptoms of human autism.
5. Smith M, Spence MA, Flodman P. {{Nuclear and mitochondrial genome defects in autisms}}. {Ann N Y Acad Sci};2009 (Jan);1151:102-132.
In this review we will evaluate evidence that altered gene dosage and structure impacts neurodevelopment and neural connectivity through deleterious effects on synaptic structure and function, and evidence that the latter are key contributors to the risk for autism. We will review information on alterations of structure of mitochondrial DNA and abnormal mitochondrial function in autism and indications that interactions of the nuclear and mitochondrial genomes may play a role in autism pathogenesis. In a final section we will present data derived using Affymetrix SNP 6.0 microarray analysis of DNA of a number of subjects and parents recruited to our autism spectrum disorders project. We include data on two sets of monozygotic twins. Collectively these data provide additional evidence of nuclear and mitochondrial genome imbalance in autism and evidence of specific candidate genes in autism. We present data on dosage changes in genes that map on the X chromosomes and the Y chromosome. Precise analyses of Y located genes are often difficult because of the high degree of homology of X- and Y-related genes. However, continued efforts to analyze the latter are important, given the consistent evidence for a 4:1 ratio of males to females affected by autism. It is also important to consider whether environmental factors play a role in generating the nuclear and mitochondrial genomic instability we have observed. The study of autism will benefit from a move to analysis of pathways and multigene clusters for identification of subtypes that share a specific genetic etiology.
