Social and non‐social visual attention patterns and associative learning in infants at risk for autism

Background: Social inattention is common in children with autism whereas associative learning capabilities are considered a relative strength. Identifying early precursors of impairment associated with autism could lead to earlier identification of this disorder. The present study compared social and non‐social visual attention patterns as well as associative learning in infant siblings of children with autism (AU sibs) and low‐risk (LR) infants at 6 months of age. Methods: Twenty‐five AU sibs and 25 LR infants were observed in a novel social‐object learning task, within which attention to social and non‐social cues was contrasted. Video recorded data were coded for percent duration of gaze to objects or caregiver. Movement rates to activate the toy within the associative learning task were also quantified. Results: Both groups learned the association between moving a switch and activating a cause–effect toy. AU sibs spent less time looking at caregivers and more time looking at the toy or joystick when their caregivers made no attempts to engage their attention. However, response to caregiver‐initiated social bids was comparable for both groups. Conclusions: Infrequent self‐initiated socially directed gaze may be an early marker of later social and communication delays.     

Multiple branch retinal arteriolar occlusions associated with smallpox vaccination

We describe a rare combination of multiple multiple branch retinal arteriolar occlusions (BRAO) and encephalopathy, which developed in an adult male 10 days after smallpox vaccination. A 53-year-old physician presented with sudden temporal visual field loss in the left eye. Ten days earlier he had received a smallpox vaccination. Hyperbaric oxygen was administered because of suspected BRAO. Examination on day 3 revealed a decrease in visual acuity and loss of visual field. Fundoscopy of the left eye disclosed a retinal infarct in the inferior macula and multiple cotton wool spots over the entire posterior pole. Fluorescein angiography showed delayed arterial filling and multiple non-perfused areas. Magnetic resonance imaging of the brain disclosed white matter focal lesions. Neurological examination was normal. Audiological examination revealed mild hearing loss caused by an old phonic trauma. A combination of intravenous methylprednisolone and immunoglobulins, recommended for the treatment of Susac syndrome, was administered. At the follow-up visit 3 months later, visual acuity in the left eye improved, fundoscopy showed resolution of the cotton wool spots and temporal disc pallor, and the visual field was substantially restored.     

Differential behavioral profile induced by the injection of dipotassium chlorazepate within brain areas that project to the nucleus accumbens septi

BackgroundThe effect of the agonism on γ-aminobutyric acid (GABA) receptors was studied within medial prefrontal cortex (mPFC), amygdala (AMY) and ventral hipocampus (VH) in the plus-maze test in male rats bilaterally cannulated. These structures send glutamatergic projections to the nucleus accumbens septi (NAS), in which interaction and integration between these afferent pathways has been described. In a previous study of our group, blockade of glutamatergic transmission within NAS induced an anxiolytic like effectMethodsThree rat groups received either saline or dipotassium chlorazepate (1 or 2 μg/1 μl solution) 15 min before testing. Time spent in the open arms (TSOA), time per entry (TPE), extreme arrivals (EA), open and closed arms entries (OAE, CAE) and relationship between open- and closed-arms quotient (OCAQ) were recordedResultsIn the AMY injected group TSOA, OAE and EA were increased by the higher doses of dipotassium chlorazepate (p < 0.01). In the mPFC, TPE was decreased by both doses (p < 0.05). Injection within ventral hippocampus (VH) decreased TSOA, OAE and OCAQ with lower doses (p < 0.05). When the three studied saline groups were compared, TSOA, OAE, EA and OCAQ were enhanced in the VH group when compared to mPFC and AMY(p < 0.001). Insertion of inner canula (p < 0.001, p < 0.01, p < 0.01) and saline injection showed an increasing significant difference (p < 0.001 in all cases) with the action of guide cannula alone within VH in TSOA, OAE and EA.ConclusionWe conclude that the injection of dipotassium chlorazepate has a differential effect depending of the brain area, leading to facilitatory and inhibitory effects on anxiety processing.