[Abstract Title]. - Society for Neuroscience

arranged in three clusters (Pcdh-α, -β, and -γ) at a single chromosomal locus in mammals.
Protocadherins derived from each of these clusters are combinatorially expressed by developing
neurons, in which they localize preferentially to synaptic and perisynaptic sites. Although they
contain 6 extracellular cadherin domains, there is little evidence that the clustered Pcdhs mediate
strong cell-cell adhesion in the nervous system, suggesting that they may have other cellular
functions. In the course of our analysis of the 22-gene Pcdh-γ cluster, we found that γ-Pcdh
proteins are expressed by epithelial cells of the choroid plexus and ependyma at levels higher
than those in neurons or astrocytes. Surprisingly, γ-Pcdh proteins do not localize to the adherens
junctions that are formed basolaterally between adjacent epithelial cells, but are instead tightly
restricted to the apical membrane. Whole-mount immunostaining reveals that γ-Pcdh proteins
localize throughout most of the apical membrane of developing and adult choroid plexus
epithelia, but are excluded both from the tufts of cilia that project from this membrane, as well as
from the tight junctions that separate it from the basolateral membrane. RT-PCR analysis of
isolated choroid plexus RNA detects transcripts encoding many, but not all, of the 22 Pcdh-γ
genes, as well as members of several other protocadherin families, including Fat, Dachsous, and
Celsr, that have been implicated in planar cell polarity. Because the apical surface of ependymal
and choroid plexus epithelial cells is exposed only to cerebrospinal fluid, and not to other cells,
the restricted localization we observe suggests that the γ-Pcdhs have novel, non-adhesive
functions in these cell types. Because Pcdh-γ null mutants die at birth, precluding many
experiments, we are currently testing this hypothesis by utilizing a new, loxP-flanked conditional
mutant allele (Pcdh-γ con ) and a transgenic mouse line expressing Cre specifically in ciliated
epithelial cells.
Disclosures: J.A. Weiner , None; L.F. Helsper, None.
Poster
288. Working Memory: Disorders, Genes and Connectivity
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 288.1/RR8
Topic: F.01.f. Working memory
Support: University Research Foundation
Mind and Life Varela Award
Title: Mindfulness training improves working memory performance in adults with ADHD
Authors: Z. B. ROSEN 1 , M. J. BAIME 2 , J. R. RAMSAY 3 , A. ROSTAIN 4 , K. K.
SREENIVASAN 1 , *A. P. JHA 5 ;