Neurons in the rat occipital cortex co-expressing the substance P-receptor and GABA: a comparison between in vivo and organotypic cultures.
The morphology and the distribution of neurons expressing the NK1-receptor (NK1R) and the co-expression of gamma-aminobutyric acid (GABA) in these neurons were studied in the rat occipital cortex and in organotypic cultures (OTCs) derived from this structure. By employing immunohistochemistry, we demonstrate that the NK1R-expressing neurons are non-pyramidal neurons and co-express GABA. Some differences were noted between in vivo and OTCs. NK1R-expressing neurons in OTCs had larger somata and longer dendrites and the proportion stained with an anti-GABA-antibody (approximately 50%) was smaller than in vivo (90%). The preferential location of NK1R-expressing neurons in layers II/III and VI, seen in vivo is not present in OTCs where these neurons distribute rather homogeneously through layers II-VI. Our findings imply that in contrast to the cat and monkey, in the rat occipital cortex the effects of substance P are almost exclusively mediated via inhibitory interneurons.
Echevarría
D
D
Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
Matute
C
C
Albus
K
K
D000818:Animals; D005455:Fluorescent Antibody Technique; D007158:Immunologic Techniques; D009474:Neurons / Q000378:metabolism*; D009778:Occipital Lobe / Q000166:cytology / Q000378:metabolism*; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D018040:Receptors, Neurokinin-1 / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D018040:Receptors, Neurokinin-1; D005680:gamma-Aminobutyric Acid