Mouse cortical cholinergic neurons: Ontogeny of phenotypes in vivo and in vitro.

The development of cholinergic neurons in mouse frontal cortex was studied both in vivo and in vitro by immunocytochemistry with an antibody to choline acetyltransferase (ChAT), the enzyme responsible for acetylcholine synthesis. While cortical cholinergic neurons have previously been characterized in rat cortex, up until very recently, intrinsic cortical cholinergic neurons were considered to be absent in mouse, and little is known about their development or phenotypic characteristics. The present study found no ChAT-positive neurons in mouse frontal cortex on postnatal day 0 (P0, the day of birth). On P7 there were few, faintly stained, ChAT-positive neurons. The numerical density of ChAT-positive neurons increased substantially with age, from none on P0, to 9.2 + 1.4 on P7, to 14.8 + 0.9 on P16, and 41.6 + 3.9 in adulthood. Considering that the numerical density of total neurons decreases during this postnatal period, the data represent a marked developmental increase in the percentage of cholinergic neurons. The development of cholinergic neurons showed very similar timelines in rat and mouse frontal cortex. Cultures prepared from mouse frontal cortex on embryonic day 16 were maintained for 25, 76, or 100 days in vitro (div). The percentage of ChAT-positive neurons was considerably higher than in vivo, ranging from a mean 28% to 31% across the three age (div) groups. With increasing age of the cultures, the numerical density of total neurons and ChAT-positive neurons decreased while the percentage of ChAT-positive neurons did not change significantly. These observations suggest some temporal stability in the cultures. Using dual immunofluorescence, ChAT-positive neurons were tested for colocalization with GAD or TH. The majority of ChAT-positive neurons colocalized with GAD, both in vitro and in vivo. However, ChAT did not colocalize with TH, either in vitro or in vivo. Our comparison of intact frontal cortex and cultures suggest that while the percentage of cholinergic neurons was greater in the cultures, the cholinergic neurons developed phenotypic similarities in vitro and in vivo.

Grantor dc:publisher

University of North Texas

Year dc:date

2005

Author dc:creator

• Coiculescu, Olivia Elena

Contributors dc:contributor

• Fuchs, Jannon L.
• Gross, Guenter W.
• Schwark, Harris
• Benjamin, Robert C.
• Uphouse, Lynda

• Acetylcholine -- Receptors.
• Mice -- Nervous system.
• Cerebral cortex.
• Neurons.
• cortical cholinergic neurons
• colocalization
• ChAT
• immunocytochemistry
• mouse frontal cortex

Statement dc:rights

• Public
• Copyright
• Coiculescu, Olivia Elena
• Copyright is held by the author, unless otherwise noted. All rights reserved.

Language dc:language

English

Identifier

oclc: 67530940
https://digital.library.unt.edu/ark:/67531/metadc4890/
ark: ark:/67531/metadc4890

OAI identifier oai:identifier

info:ark/67531/metadc4890