Quantitative study of NPY-expressing GABAergic neurons and axons in rat spinal dorsal horn
| Autor: | Thomas C. P. Sardella, Masahiko Watanabe, Erika Polgár, Andrew J. Todd |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Male
inhibitory interneuron Lamina Vesicular Inhibitory Amino Acid Transport Proteins neurokinin 1 receptor Inhibitory postsynaptic potential confocal microscopy gamma-Aminobutyric acid 03 medical and health sciences 0302 clinical medicine Interneurons Tachykinin receptor 1 mental disorders medicine Animals Neuropeptide Y Rats Wistar Posterior Horn Cell Protein Kinase C gamma-Aminobutyric Acid 030304 developmental biology Neurons 0303 health sciences Gephyrin biology PKCγ General Neuroscience fungi Membrane Proteins Receptors Neurokinin-1 Neuropeptide Y receptor gephyrin humanities Axons Rats Posterior Horn Cells nervous system biology.protein GABAergic projection neuron Carrier Proteins Neuroscience 030217 neurology & neurosurgery medicine.drug Research Article |
| Zdroj: | The Journal of Comparative Neurology |
| ISSN: | 1096-9861 |
| Popis: | Between 25–40% of neurons in laminae I–III are GABAergic, and some of these express neuropeptide Y (NPY). We previously reported that NPY-immunoreactive axons form numerous synapses on lamina III projection neurons that possess the neurokinin 1 receptor (NK1r). The aims of this study were to determine the proportion of neurons and GABAergic boutons in this region that contain NPY, and to look for evidence that they selectively innervate different neuronal populations. We found that 4–6% of neurons in laminae I–III were NPY-immunoreactive and based on the proportions of neurons that are GABAergic, we estimate that NPY is expressed by 18% of inhibitory interneurons in laminae I–II and 9% of those in lamina III. GABAergic boutons were identified by the presence of the vesicular GABA transporter (VGAT) and NPY was found in 13–15% of VGAT-immunoreactive boutons in laminae I–II, and 5% of those in lamina III. For both the lamina III NK1r-immunoreactive projection neurons and protein kinase Cγ (PKCγ)-immunoreactive interneurons in lamina II, we found that around one-third of the VGAT boutons that contacted them were NPY-immunoreactive. However, based on differences in the sizes of these boutons and the strength of their NPY-immunoreactivity, we conclude that these originate from different populations of interneurons. Only 6% of VGAT boutons presynaptic to large lamina I projection neurons that lacked NK1rs contained NPY. These results show that NPY-containing neurons make up a considerable proportion of the inhibitory interneurons in laminae I–III, and that their axons preferentially target certain classes of dorsal horn neuron. J. Comp. Neurol. 519:1007–1023, 2011. © 2010 Wiley-Liss, Inc. |
| Databáze: | OpenAIRE |
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