Journal article
Spine formation and maturation in the developing rat auditory cortex
Journal of comparative neurology (1911), Vol.519(16), pp.3327-3345
11/01/2011
DOI: 10.1002/cne.22728
PMCID: PMC3905797
PMID: 21800311
Abstract
The rat auditory cortex is organized as a tonotopic map of sound frequency. This map is broadly tuned at birth and is refined during the first 3 weeks postnatal. The structural correlates underlying tonotopic map maturation and reorganization during development are poorly understood. We employed fluorescent dye ballistic labeling ("DiOlistics") alone, or in conjunction with immunohistochemistry, to quantify synaptogenesis in the auditory cortex of normal hearing rats. We show that the developmental appearance of dendritic protrusions, which include both immature filopodia and mature spines, on layers 2/3, 4, and 5 pyramidal and layer 4 spiny nonpyramidal neurons occurs in three phases: slow addition of dendritic protrusions from postnatal day 4 (P4) to P9, rapid addition of dendritic protrusions from P9 to P19, and a final phase where mature protrusion density is achieved (>P21). Next, we combined DiOlistics with immunohistochemical labeling of bassoon, a presynaptic scaffolding protein, as a novel method to categorize dendritic protrusions as either filopodia or mature spines in cortex fixed in vivo. Using this method we observed an increase in the spine-to-filopodium ratio from P9-P16, indicating a period of rapid spine maturation. Previous studies report mature spines as being shorter in length compared to filopodia. We similarly observed a reduction in protrusion length between P9 and P16, corroborating our immunohistochemical spine maturation data. These studies show that dendritic protrusion formation and spine maturation occur rapidly at a time previously shown to correspond to auditory cortical tonotopic map refinement (P11-P14), providing a structural correlate of physiological maturation.
Details
- Title: Subtitle
- Spine formation and maturation in the developing rat auditory cortex
- Creators
- Scott J Schachtele - Department of Biological Sciences, University of Iowa, Iowa City, Iowa 52242-1109, USAJoe LoshMichael E DaileySteven H Green
- Resource Type
- Journal article
- Publication Details
- Journal of comparative neurology (1911), Vol.519(16), pp.3327-3345
- DOI
- 10.1002/cne.22728
- PMID
- 21800311
- PMCID
- PMC3905797
- NLM abbreviation
- J Comp Neurol
- ISSN
- 0021-9967
- eISSN
- 1096-9861
- Publisher
- United States
- Grant note
- R29 NS037159 / NINDS NIH HHS S10 RR017941 / NCRR NIH HHS DC02961 / NIDCD NIH HHS R01 DC002961 / NIDCD NIH HHS
- Language
- English
- Date published
- 11/01/2011
- Academic Unit
- Iowa Neuroscience Institute; Biology; Otolaryngology
- Record Identifier
- 9983992064002771
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