ABSTRACT
The human HOXA1 mutation syndromes commonly present with abnormalities of the inner ear and ICAs. Previous cases describe varying degrees of hypoplasia or aplasia of the affected structures, often with asymmetric involvement. We present imaging findings documenting complete absence of the ICAs bilaterally with bilateral CLA, which, to our knowledge, has not been previously reported.
Subject(s)
Carotid Artery, Internal/abnormalities , Developmental Disabilities/genetics , Ear, Inner/abnormalities , Homeodomain Proteins/genetics , Ocular Motility Disorders/genetics , Transcription Factors/genetics , Brain Stem/abnormalities , Brain Stem/pathology , Carotid Artery, Internal/pathology , Child, Preschool , Developmental Disabilities/pathology , Ear, Inner/pathology , Female , Hearing Loss, Sensorineural , Humans , Indians, North American , Magnetic Resonance Angiography , Magnetic Resonance Imaging , Nervous System Malformations/genetics , Nervous System Malformations/pathology , Ocular Motility Disorders/pathologyABSTRACT
Adult rats with amygdala lesions made at either Postnatal Day (PND) 10 or PND40 were tested on a series of reversal tasks that tap the ability to form stimulus-reward associations. PND40 rats were significantly impaired relative to both controls and PND10 rats on learning rate of the original discrimination and subsequent reversals. Analyses of discrete learning phases revealed that the impairment was specific to the postchance phase. The PND10 group was not impaired relative to controls on any measure. These results confirm prior findings that amygdala lesions sustained in adulthood impair the formation of stimulus-reward associations. They also demonstrate that substantial sparing or recovery of function is possible when the lesion is made during early development. Furthermore, the findings support the view that behavioral recovery may be more likely if the lesion is sustained near the time of peak synaptogenesis.
