Biology subjects

Hooks, B. M.

Publications and source records attributed to Hooks, B. M..

2 recordsLinked to original sources

bioRxiv2018

Cell type-specific variation of somatotopic precision across corticostriatal projections

The striatum shows general topographic organization and regional differences in behavioral functions. How corticostriatal topography differs across cortical areas and cell types to support these distinct functions is unclear. This study contrasted corticostriatal projections from two layer 5 cell types, intratelencephalic (IT-type) and pyramidal tract (PT-type) neurons, using viral vectors expressing fluorescent reporters in Cre-driver mice. Long-range corticostriatal projections from sensory and motor cortex are somatotopic, with a decreasing somatotopic specificity as injections move from sensory to motor and frontal areas. Somatotopic organization differs between IT-type and PT-type neurons, including injections in the same site, with IT-type neurons having higher somatotopic stereotypy than PT-type neurons. Furthermore, IT-type projections from interconnected cortical areas have stronger correlations in corticostriatal targeting than PT-type projections do. Thus, as predicted by a long-standing basal ganglia model, corticostriatal projections of interconnected cortical areas form parallel circuits in basal ganglia-thalamus-cortex loops.

neuroscience↗

bioRxiv2017

The Transcriptional Logic of Mammalian Neuronal Diversity

The mammalian nervous system is constructed of many cell types, but the principles underlying this diversity are poorly understood. To assess brain-wide transcriptional diversity, we sequenced the transcriptomes of the largest collection of genetically and anatomically identified neuronal classes. Using improved expression metrics that distinguish information content from signal-to-noise-ratio, we found that homeobox transcription factors contain the highest information about cell types and have the lowest noise. Genes that contribute the most to neuronal diversity tend to be long and enriched in factors specifically involved in neuronal function. Genome accessibility measurements reveal that long genes have more candidate regulatory elements arrayed in more distinct patterns. These elements frequently overlap interspersed repeats (mobile elements) and the pattern of repeats is predictive of gene expression. New regulatory sites resulting from elongation of neuronal genes by mobile elements may be an evolutionary force enhancing nervous system complexity.

neuroscience↗