Vasotocin neurons and septal V1a-like receptors potently modulate songbird flocking and responses to novelty.

Previous comparisons of territorial and gregarious finches (family Estrildidae) suggest the hypothesis that arginine vasotocin (VT) neurons in the medial bed nucleus of the stria terminalis (BSTm) and V(1a)-like receptors in the lateral septum (LS) promote flocking behavior. Consistent with this hypothesis, we now show that intraseptal infusions of a V(1a) antagonist in male zebra finches (Taeniopygia guttata) reduce gregariousness (preference for a group of 10 versus 2 conspecific males), but have no effect on the amount of time that subjects spend in close proximity to other birds ("contact time"). The antagonist also produces a profound increase in anxiety-like behavior, as exhibited by an increased latency to feed in a novelty-suppressed feeding test.

Behavioral effects of hindbrain vasotocin in goldfish are seasonally variable but not sexually dimorphic.

We have previously demonstrated that centrally administered vasotocin (VT) inhibits social approach toward same-sex conspecifics in male and female goldfish, and that this behavioral effect is dependent upon VT projections to the hindbrain. We now show that there are no sex differences in sensitivity to the behavioral effects of VT, though differences do exist in responsiveness across seasons in both sexes. A central dose of 1 microg, but not 200 ng, inhibited social approach in goldfish in non-reproductive condition, whereas a dose as low as 40 ng inhibited social approach in fish in full reproductive condition.

Olfactory biopsies demonstrate a defect in neuronal development in Rett's syndrome.

Rett's Syndrome (RTT) is a neurodevelopmental disorder resulting from mutation in the mecp2 gene that encodes methyl CpG binding protein 2, a transcriptional repressor. Because this disease primarily affects neurons, tissue is not available during active disease. We used the olfactory system as a model to investigate abnormalities in neuronal development in RTT, because olfactory receptor neurons (ORNs) are replaced throughout life by ongoing postnatal neurogenesis.

Rapid genotyping of common MeCP2 mutations with an electronic DNA microchip using serial differential hybridization.

Rett syndrome is a neurodevelopmental disorder that affects females almost exclusively, and in which eight common point mutations on the X-linked MeCP2 gene are knows to cause over 70% of mutation-positive cases. We explored the use of a novel platform to detect the eight common mutations in Rett syndrome patients to expedite and simplify the process of identification of known genotypes. The Nanogen workstation consists of a two-color assay based on electric hybridization and thermal discrimination, all performed on an electronically active NanoChip.

Mutations in COX15 produce a defect in the mitochondrial heme biosynthetic pathway, causing early-onset fatal hypertrophic cardiomyopathy.

Deficiencies in the activity of cytochrome c oxidase (COX), the terminal enzyme in the respiratory chain, are a frequent cause of autosomal recessive mitochondrial disease in infants. These patients are clinically and genetically heterogeneous, and all defects so far identified in this group have been found in genes coding for accessory proteins that play important roles in the assembly of the COX holoenzyme complex. Many patients, however, remain without a molecular diagnosis.