Patterning events and specification signals in the developing hippocampus.
The mouse hippocampus is an attractive model system in which to study patterning of a cortical structure. Ongoing studies indicate that hippocampal areas or fields are specified many days before birth -- possibly involving signals from within the cortical mantle. Although the hippocampal CA fields are distinguished by cytoarchitecture only after birth, molecular differences between fields appear by late gestation. Moreover, these embryonic fields are already specified to develop additional features that characterize the mature fields. The basic division of the hippocampus into fields may be specified still earlier. Thus, if medial cortical neuroepithelium is isolated in vitro early in hippocampal neurogenesis, it can autonomously generate features of a patterned hippocampus. In vivo, the spatial progression of initial field differentiation suggests that signals regulating growth and patterning could arise from sources close to the hippocampal poles. Observations of mouse mutants indicate that the cortical hem, an embryonic structure close to one pole of the hippocampus, is a source of such regulatory signals.
Grove
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Department of Neurobiology, Pharmacology and Physiology, University of Chicago, IL 60637, USA. egrove@drugs.bsd.uchicago.edu
Tole
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D000367:Age Factors; D000818:Animals; D015415:Biomarkers; D019485:Bone Morphogenetic Proteins / Q000235:genetics; D019070:Cell Lineage / Q000502:physiology; D002540:Cerebral Cortex / Q000196:embryology; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006624:Hippocampus / Q000737:chemistry / Q000166:cytology / Q000196:embryology*; D017403:In Situ Hybridization; D051379:Mice; D008817:Mice, Mutant Strains; D009419:Nerve Tissue Proteins / Q000235:genetics; D009474:Neurons / Q000737:chemistry / Q000166:cytology / Q000502:physiology; D050816:Octamer Transcription Factor-6; D011247:Pregnancy; D011518:Proto-Oncogene Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D018092:Kainic Acid Receptors / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D051153:Wnt Proteins; D029961:Zebrafish Proteins
D015415:Biomarkers; D019485:Bone Morphogenetic Proteins; D009419:Nerve Tissue Proteins; D050816:Octamer Transcription Factor-6; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D018092:Kainic Acid Receptors; D014157:Transcription Factors; D051153:Wnt Proteins; D029961:Zebrafish Proteins; C494180:Pou3f1 protein, mouse; C494179:Pou3f1 protein, rat