Chunk #228 — VIII. A possible underlying neurobiology: connectivity constellations — B. Quality and/or quantity of connections involved in vulnerabilities
These data strongly imply roles for individual differences in the quantity of neuronal connections in heritable determinants of cognitive function. No human data of which we are aware directly address qualitative differences in neuronal connections. However, it seems unlikely that genes that influence quantity would fail to influence quality of connections as well. Interrelations between neurons and glia are also likely to provide significant contributions to the anatomic coherence of white matter pathways. It seems likely that the interindividual differences in diffusion tensor imaging signals that come from white matter differences and that can readily be observed in humans [248] will also receive contributions from “connectivity constellation” genes, to the extent that these individual differences are heritable [249, 250].
